fmt: group_imports = "StdExternalCrate"

feat: bytecode
refactor: use GhostCell to provide interior mutability in Ir
2026-03-08 17:41:06 +08:00 · 2026-03-08 17:41:06 +08:00 · 2026-03-08 16:57:34 +08:00 · 2026-02-25 21:14:35 +08:00 · 2026-02-25 21:14:27 +08:00 · 2026-02-21 22:30:13 +08:00
508 changed files with 9777 additions and 4197 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,6 @@ flamegraph*.svg
 perf.data*
 profile.json.gz
 prof.json
+*.cpuprofile
+*.cpuprofile.gz
+*v8.log*
--- a/.lazy.lua
+++ b/.lazy.lua
@@ -3,5 +3,25 @@ vim.lsp.config("biome", {
    on_dir(vim.fn.getcwd())
  end
 })
+vim.lsp.config("eslint", {
+  settings = {
+    eslint = {
+      options = {
+        configFile = "./nix-js/runtime-ts/eslint.config.mts"
+      }
+    }
+  }
+})
+vim.lsp.config("rust_analyzer", {
+  settings = {
+    ["rust-analyzer"] = {
+      cargo = {
+        features = {
+          "inspector"
+        }
+      }
+    }
+  }
+})

 return {}
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -47,12 +47,56 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"

+[[package]]
+name = "anstream"
+version = "0.6.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43d5b281e737544384e969a5ccad3f1cdd24b48086a0fc1b2a5262a26b8f4f4a"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
 [[package]]
 name = "anstyle"
 version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"

+[[package]]
+name = "anstyle-parse"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+dependencies = [
+ "anstyle",
+ "once_cell_polyfill",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "anyhow"
 version = "1.0.101"
@@ -123,6 +167,12 @@ dependencies = [
 "backtrace",
 ]

+[[package]]
+name = "base64"
+version = "0.21.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
+
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -239,9 +289,12 @@ dependencies = [

 [[package]]
 name = "bumpalo"
-version = "3.19.1"
+version = "3.20.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5dd9dc738b7a8311c7ade152424974d8115f2cdad61e8dab8dac9f2362298510"
+checksum = "5d20789868f4b01b2f2caec9f5c4e0213b41e3e5702a50157d699ae31ced2fcb"
+dependencies = [
+ "allocator-api2",
+]

 [[package]]
 name = "bytes"
@@ -379,21 +432,36 @@ dependencies = [

 [[package]]
 name = "clap"
-version = "4.5.58"
+version = "4.5.59"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "63be97961acde393029492ce0be7a1af7e323e6bae9511ebfac33751be5e6806"
+checksum = "c5caf74d17c3aec5495110c34cc3f78644bfa89af6c8993ed4de2790e49b6499"
 dependencies = [
 "clap_builder",
+ "clap_derive",
 ]

 [[package]]
 name = "clap_builder"
-version = "4.5.58"
+version = "4.5.59"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f13174bda5dfd69d7e947827e5af4b0f2f94a4a3ee92912fba07a66150f21e2"
+checksum = "370daa45065b80218950227371916a1633217ae42b2715b2287b606dcd618e24"
 dependencies = [
+ "anstream",
 "anstyle",
 "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.5.55"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a92793da1a46a5f2a02a6f4c46c6496b28c43638adea8306fcb0caa1634f24e5"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
 ]

 [[package]]
@@ -420,6 +488,21 @@ dependencies = [
 "cc",
 ]

+[[package]]
+name = "colorchoice"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
+
+[[package]]
+name = "colored"
+version = "3.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "faf9468729b8cbcea668e36183cb69d317348c2e08e994829fb56ebfdfbaac34"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "combine"
 version = "4.6.7"
@@ -888,6 +971,27 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c34f04666d835ff5d62e058c3995147c06f42fe86ff053337632bca83e42702d"

+[[package]]
+name = "env_filter"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a1c3cc8e57274ec99de65301228b537f1e4eedc1b8e0f9411c6caac8ae7308f"
+dependencies = [
+ "log",
+]
+
+[[package]]
+name = "env_logger"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2daee4ea451f429a58296525ddf28b45a3b64f1acf6587e2067437bb11e218d"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "env_filter",
+ "log",
+]
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -962,6 +1066,26 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"

+[[package]]
+name = "fastwebsockets"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "305d3ba574508e27190906d11707dad683e0494e6b85eae9b044cb2734a5e422"
+dependencies = [
+ "base64 0.21.7",
+ "bytes",
+ "http-body-util",
+ "hyper",
+ "hyper-util",
+ "pin-project",
+ "rand 0.8.5",
+ "sha1",
+ "simdutf8",
+ "thiserror 1.0.69",
+ "tokio",
+ "utf-8",
+]
+
 [[package]]
 name = "fd-lock"
 version = "4.0.4"
@@ -1051,9 +1175,9 @@ checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"

 [[package]]
 name = "futures"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65bc07b1a8bc7c85c5f2e110c476c7389b4554ba72af57d8445ea63a576b0876"
+checksum = "8b147ee9d1f6d097cef9ce628cd2ee62288d963e16fb287bd9286455b241382d"
 dependencies = [
 "futures-channel",
 "futures-core",
@@ -1066,9 +1190,9 @@ dependencies = [

 [[package]]
 name = "futures-channel"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2dff15bf788c671c1934e366d07e30c1814a8ef514e1af724a602e8a2fbe1b10"
+checksum = "07bbe89c50d7a535e539b8c17bc0b49bdb77747034daa8087407d655f3f7cc1d"
 dependencies = [
 "futures-core",
 "futures-sink",
@@ -1076,15 +1200,15 @@ dependencies = [

 [[package]]
 name = "futures-core"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05f29059c0c2090612e8d742178b0580d2dc940c837851ad723096f87af6663e"
+checksum = "7e3450815272ef58cec6d564423f6e755e25379b217b0bc688e295ba24df6b1d"

 [[package]]
 name = "futures-executor"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e28d1d997f585e54aebc3f97d39e72338912123a67330d723fdbb564d646c9f"
+checksum = "baf29c38818342a3b26b5b923639e7b1f4a61fc5e76102d4b1981c6dc7a7579d"
 dependencies = [
 "futures-core",
 "futures-task",
@@ -1093,15 +1217,15 @@ dependencies = [

 [[package]]
 name = "futures-io"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e5c1b78ca4aae1ac06c48a526a655760685149f0d465d21f37abfe57ce075c6"
+checksum = "cecba35d7ad927e23624b22ad55235f2239cfa44fd10428eecbeba6d6a717718"

 [[package]]
 name = "futures-macro"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "162ee34ebcb7c64a8abebc059ce0fee27c2262618d7b60ed8faf72fef13c3650"
+checksum = "e835b70203e41293343137df5c0664546da5745f82ec9b84d40be8336958447b"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -1110,21 +1234,21 @@ dependencies = [

 [[package]]
 name = "futures-sink"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e575fab7d1e0dcb8d0c7bcf9a63ee213816ab51902e6d244a95819acacf1d4f7"
+checksum = "c39754e157331b013978ec91992bde1ac089843443c49cbc7f46150b0fad0893"

 [[package]]
 name = "futures-task"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f90f7dce0722e95104fcb095585910c0977252f286e354b5e3bd38902cd99988"
+checksum = "037711b3d59c33004d3856fbdc83b99d4ff37a24768fa1be9ce3538a1cde4393"

 [[package]]
 name = "futures-util"
-version = "0.3.31"
+version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9fa08315bb612088cc391249efdc3bc77536f16c91f6cf495e6fbe85b20a4a81"
+checksum = "389ca41296e6190b48053de0321d02a77f32f8a5d2461dd38762c0593805c6d6"
 dependencies = [
 "futures-channel",
 "futures-core",
@@ -1134,7 +1258,6 @@ dependencies = [
 "futures-task",
 "memchr",
 "pin-project-lite",
- "pin-utils",
 "slab",
 ]

@@ -1188,6 +1311,12 @@ dependencies = [
 "wasip3",
 ]

+[[package]]
+name = "ghost-cell"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8449d342b1c67f49169e92e71deb7b9b27f30062301a16dbc27a4cc8d2351b7"
+
 [[package]]
 name = "gimli"
 version = "0.32.3"
@@ -1315,6 +1444,12 @@ version = "1.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6dbf3de79e51f3d586ab4cb9d5c3e2c14aa28ed23d180cf89b4df0454a69cc87"

+[[package]]
+name = "httpdate"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
+
 [[package]]
 name = "hyper"
 version = "1.8.1"
@@ -1328,6 +1463,7 @@ dependencies = [
 "http",
 "http-body",
 "httparse",
+ "httpdate",
 "itoa",
 "pin-project-lite",
 "pin-utils",
@@ -1358,7 +1494,7 @@ version = "0.1.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "96547c2556ec9d12fb1578c4eaf448b04993e7fb79cbaad930a656880a6bdfa0"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bytes",
 "futures-channel",
 "futures-util",
@@ -1578,6 +1714,12 @@ dependencies = [
 "windows-sys 0.60.2",
 ]

+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
+
 [[package]]
 name = "itertools"
 version = "0.13.0"
@@ -1781,6 +1923,12 @@ dependencies = [
 "regex-automata",
 ]

+[[package]]
+name = "md5"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae960838283323069879657ca3de837e9f7bbb4c7bf6ea7f1b290d5e9476d2e0"
+
 [[package]]
 name = "memchr"
 version = "2.8.0"
@@ -1877,7 +2025,7 @@ dependencies = [
 [[package]]
 name = "nix-compat"
 version = "0.1.0"
-source = "git+https://git.snix.dev/snix/snix.git#9d414bec7c7fff1fca6ba6d14dda6c4295521260"
+source = "git+https://git.snix.dev/snix/snix.git#1b37f68842a7e5e226d9dc009e9a90d400c5fb14"
 dependencies = [
 "bitflags",
 "bstr",
@@ -1900,7 +2048,7 @@ dependencies = [
 [[package]]
 name = "nix-compat-derive"
 version = "0.1.0"
-source = "git+https://git.snix.dev/snix/snix.git#9d414bec7c7fff1fca6ba6d14dda6c4295521260"
+source = "git+https://git.snix.dev/snix/snix.git#1b37f68842a7e5e226d9dc009e9a90d400c5fb14"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -1912,18 +2060,28 @@ name = "nix-js"
 version = "0.1.0"
 dependencies = [
 "anyhow",
- "base64",
+ "base64 0.22.1",
+ "bumpalo",
 "bzip2",
+ "clap",
+ "colored",
 "criterion",
 "deno_core",
 "deno_error",
 "derive_more",
 "dirs",
 "ere",
+ "fastwebsockets",
 "flate2",
+ "ghost-cell",
 "hashbrown 0.16.1",
 "hex",
+ "http",
+ "http-body-util",
+ "hyper",
+ "hyper-util",
 "itertools 0.14.0",
+ "md5",
 "miette",
 "mimalloc",
 "nix-compat",
@@ -1939,16 +2097,19 @@ dependencies = [
 "rustyline",
 "serde",
 "serde_json",
+ "sha1",
 "sha2",
 "string-interner",
 "tap",
 "tar",
 "tempfile",
+ "test-log",
 "thiserror 2.0.18",
 "tokio",
 "toml",
 "tracing",
 "tracing-subscriber",
+ "uuid",
 "xz2",
 ]

@@ -1957,6 +2118,7 @@ name = "nix-js-macros"
 version = "0.1.0"
 dependencies = [
 "convert_case 0.11.0",
+ "proc-macro2",
 "quote",
 "syn",
 ]
@@ -2067,6 +2229,12 @@ version = "1.21.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"

+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+
 [[package]]
 name = "oorandom"
 version = "11.1.5"
@@ -2359,6 +2527,8 @@ version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
+ "libc",
+ "rand_chacha 0.3.1",
 "rand_core 0.6.4",
 ]

@@ -2368,10 +2538,20 @@ version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
 dependencies = [
- "rand_chacha",
+ "rand_chacha 0.9.0",
 "rand_core 0.9.5",
 ]

+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.6.4",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.9.0"
@@ -2484,7 +2664,7 @@ version = "0.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ab3f43e3283ab1488b624b44b0e988d0acea0b3214e694730a055cb6b2efa801"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bytes",
 "futures-channel",
 "futures-core",
@@ -2541,9 +2721,9 @@ dependencies = [

 [[package]]
 name = "rnix"
-version = "0.13.0"
+version = "0.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b8276b540c344ec04cd215fb3d35db378c2b1861cc44802c2c097f3490f6e52"
+checksum = "c163bd17372eecdf10d351c34584b7de7c1a33be4e92a32f3fb3f5a7fe3f579b"
 dependencies = [
 "rowan",
 ]
@@ -2895,6 +3075,17 @@ dependencies = [
 "v8",
 ]

+[[package]]
+name = "sha1"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
 [[package]]
 name = "sha2"
 version = "0.10.9"
@@ -2946,6 +3137,12 @@ version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e320a6c5ad31d271ad523dcf3ad13e2767ad8b1cb8f047f75a8aeaf8da139da2"

+[[package]]
+name = "simdutf8"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
+
 [[package]]
 name = "slab"
 version = "0.4.12"
@@ -3045,6 +3242,12 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72abeda133c49d7bddece6c154728f83eec8172380c80ab7096da9487e20d27c"

+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "strum"
 version = "0.27.2"
@@ -3101,9 +3304,9 @@ checksum = "a7973cce6668464ea31f176d85b13c7ab3bba2cb3b77a2ed26abd7801688010a"

 [[package]]
 name = "syn"
-version = "2.0.115"
+version = "2.0.116"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e614ed320ac28113fa64972c4262d5dbc89deacdfd00c34a3e4cea073243c12"
+checksum = "3df424c70518695237746f84cede799c9c58fcb37450d7b23716568cc8bc69cb"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -3112,9 +3315,9 @@ dependencies = [

 [[package]]
 name = "syn-match"
-version = "0.3.0"
+version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "783c4140d7ed89f37116e865b49e5a9fdd28608b9071a9dd1e158b50fc0a31fc"
+checksum = "54b8f0a9004d6aafa6a588602a1119e6cdaacec9921aa1605383e6e7d6258fd6"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -3234,6 +3437,28 @@ dependencies = [
 "windows-sys 0.60.2",
 ]

+[[package]]
+name = "test-log"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37d53ac171c92a39e4769491c4b4dde7022c60042254b5fc044ae409d34a24d4"
+dependencies = [
+ "env_logger",
+ "test-log-macros",
+ "tracing-subscriber",
+]
+
+[[package]]
+name = "test-log-macros"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be35209fd0781c5401458ab66e4f98accf63553e8fae7425503e92fdd319783b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "text-size"
 version = "1.1.1"
@@ -3423,9 +3648,9 @@ dependencies = [

 [[package]]
 name = "toml_parser"
-version = "1.0.8+spec-1.1.0"
+version = "1.0.9+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0742ff5ff03ea7e67c8ae6c93cac239e0d9784833362da3f9a9c1da8dfefcbdc"
+checksum = "702d4415e08923e7e1ef96cd5727c0dfed80b4d2fa25db9647fe5eb6f7c5a4c4"
 dependencies = [
 "winnow",
 ]
@@ -3562,9 +3787,9 @@ checksum = "81b79ad29b5e19de4260020f8919b443b2ef0277d242ce532ec7b7a2cc8b6007"

 [[package]]
 name = "unicode-ident"
-version = "1.0.23"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "537dd038a89878be9b64dd4bd1b260315c1bb94f4d784956b81e27a088d9a09e"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"

 [[package]]
 name = "unicode-linebreak"
@@ -3615,6 +3840,12 @@ dependencies = [
 "serde_derive",
 ]

+[[package]]
+name = "utf-8"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09cc8ee72d2a9becf2f2febe0205bbed8fc6615b7cb429ad062dc7b7ddd036a9"
+
 [[package]]
 name = "utf8-ranges"
 version = "1.0.5"
@@ -3639,6 +3870,7 @@ version = "1.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b672338555252d43fd2240c714dc444b8c6fb0a5c5335e65a07bba7742735ddb"
 dependencies = [
+ "getrandom 0.4.1",
 "js-sys",
 "wasm-bindgen",
 ]
--- a/24
+++ b/24
@@ -1,15 +1,31 @@
 [no-exit-message]
@repl:
-  cargo run --bin repl
+  cargo run -- repl

 [no-exit-message]
@eval expr:
-  cargo run --bin eval -- '{{expr}}'
+  cargo run -- eval --expr '{{expr}}'

 [no-exit-message]
@replr:
-  cargo run --bin repl --release
+  cargo run --release -- repl

 [no-exit-message]
@evalr expr:
-  cargo run --bin eval --release -- '{{expr}}'
+  cargo run --release -- eval --expr '{{expr}}'
+
+[no-exit-message]
+@repli:
+  cargo run --release --features inspector -- --inspect-brk 127.0.0.1:9229 repl
+
+[no-exit-message]
+@evali expr:
+  cargo run --release --features inspector -- --inspect-brk 127.0.0.1:9229 eval --expr '{{expr}}'
+
+[no-exit-message]
+@replp:
+  cargo run --release --features prof -- repl
+
+[no-exit-message]
+@evalp expr:
+  cargo run --release --features prof -- eval --expr '{{expr}}'
--- a/biome.json
+++ b/biome.json
@@ -1,5 +1,5 @@
 {
-  "$schema": "https://biomejs.dev/schemas/2.3.9/schema.json",
+  "$schema": "https://biomejs.dev/schemas/2.3.14/schema.json",
  "vcs": {
    "enabled": true,
    "clientKind": "git",
@@ -20,10 +20,37 @@
  "linter": {
    "rules": {
      "style": {
-        "useNamingConvention": "warn"
+        "useNamingConvention": {
+          "level": "warn",
+          "options": {
+            "strictCase": false,
+            "conventions": [
+              {
+                "selector": { "kind": "objectLiteralProperty" },
+                "formats": ["camelCase", "PascalCase", "CONSTANT_CASE"]
+              },
+              {
+                "selector": { "kind": "typeProperty" },
+                "formats": ["camelCase", "snake_case"]
+              }
+            ]
+          }
+        }
      }
    }
  },
+  "overrides": [
+    {
+      "includes": ["**/global.d.ts"],
+      "linter": {
+        "rules": {
+          "style": {
+            "useNamingConvention": "off"
+          }
+        }
+      }
+    }
+  ],
  "javascript": {
    "formatter": {
      "arrowParentheses": "always",
--- a/flake.nix
+++ b/flake.nix
@@ -34,6 +34,7 @@
              just
              samply
              jq
+              tokei

              nodejs
              nodePackages.npm
--- a/nix-js-macros/Cargo.toml
+++ b/nix-js-macros/Cargo.toml
@@ -8,5 +8,6 @@ proc-macro = true

 [dependencies]
 convert_case = "0.11"
+proc-macro2 = "1.0"
 quote = "1.0"
 syn = { version = "2.0", features = ["full"] }
--- a/nix-js-macros/src/ir.rs
+++ b/nix-js-macros/src/ir.rs
@@ -4,22 +4,22 @@
 //! an Intermediate Representation (IR) that follows a specific pattern. It generates:
 //! 1. An enum representing the different kinds of IR nodes.
 //! 2. Structs for each of the variants that have fields.
-//! 3. `Ref` and `Mut` versions of the main enum for ergonomic pattern matching on references.
-//! 4. `From` implementations to easily convert from a struct variant (e.g., `BinOp`) to the main enum (`Ir::BinOp`).
-//! 5. A `To[IrName]` trait to provide a convenient `.to_ir()` method on the variant structs.
+//! 3. `From` implementations to easily convert from a struct variant (e.g., `BinOp`) to the main enum (`Ir::BinOp`).
+//! 4. A `To[IrName]` trait to provide a convenient `.to_ir()` method on the variant structs.

 use convert_case::{Case, Casing};
 use proc_macro::TokenStream;
 use quote::{format_ident, quote};
 use syn::{
-    FieldsNamed, Ident, Token, Type, parenthesized,
+    Expr, ExprPath, FieldsNamed, GenericArgument, GenericParam, Generics, Ident, Path, PathSegment,
+    Token, Type, TypePath, parenthesized,
    parse::{Parse, ParseStream, Result},
    punctuated::Punctuated,
    token,
 };

 /// Represents one of the variants passed to the `ir!` macro.
-pub enum VariantInput {
+enum VariantInput {
    /// A unit-like variant, e.g., `Arg`.
    Unit(Ident),
    /// A tuple-like variant with one unnamed field, e.g., `ExprRef(ExprId)`.
@@ -29,11 +29,12 @@ pub enum VariantInput {
 }

 /// The top-level input for the `ir!` macro.
-pub struct MacroInput {
+struct MacroInput {
    /// The name of the main IR enum to be generated (e.g., `Ir`).
-    pub base_name: Ident,
+    base_name: Ident,
+    generics: Generics,
    /// The list of variants for the enum.
-    pub variants: Punctuated<VariantInput, Token![,]>,
+    variants: Punctuated<VariantInput, Token![,]>,
 }

 impl Parse for VariantInput {
@@ -64,13 +65,14 @@ impl Parse for VariantInput {

 impl Parse for MacroInput {
    fn parse(input: ParseStream) -> Result<Self> {
-        // The macro input is expected to be: `IrName, Variant1, Variant2, ...`
        let base_name = input.parse()?;
-        input.parse::<Token![,]>()?;
+        let generics = Generics::parse(input)?;
+        input.parse::<Token![;]>()?;
        let variants = Punctuated::parse_terminated(input)?;

        Ok(MacroInput {
            base_name,
+            generics,
            variants,
        })
    }
@@ -81,17 +83,39 @@ pub fn ir_impl(input: TokenStream) -> TokenStream {
    let parsed_input = syn::parse_macro_input!(input as MacroInput);

    let base_name = &parsed_input.base_name;
-    let ref_name = format_ident!("{}Ref", base_name);
-    let mut_name = format_ident!("{}Mut", base_name);
+    let generic_params = &parsed_input.generics.params;
+    let mk_ident_path = |ident| Path {
+        leading_colon: None,
+        segments: Punctuated::from_iter(std::iter::once(PathSegment {
+            ident,
+            arguments: Default::default(),
+        })),
+    };
+    let generic_args = {
+        generic_params
+            .iter()
+            .map(|arg| match arg {
+                GenericParam::Lifetime(lifetime) => {
+                    GenericArgument::Lifetime(lifetime.lifetime.clone())
+                }
+                GenericParam::Const(cnst) => GenericArgument::Const(Expr::Path(ExprPath {
+                    path: mk_ident_path(cnst.ident.clone()),
+                    attrs: Vec::new(),
+                    qself: None,
+                })),
+                GenericParam::Type(ty) => GenericArgument::Type(Type::Path(TypePath {
+                    path: mk_ident_path(ty.ident.clone()),
+                    qself: None,
+                })),
+            })
+            .collect::<Punctuated<_, Token![,]>>()
+    };
+    let where_clause = &parsed_input.generics.where_clause;
    let to_trait_name = format_ident!("To{}", base_name);
    let to_trait_fn_name = format_ident!("to_{}", base_name.to_string().to_case(Case::Snake));

    let mut enum_variants = Vec::new();
    let mut struct_defs = Vec::new();
-    let mut ref_variants = Vec::new();
-    let mut mut_variants = Vec::new();
-    let mut as_ref_arms = Vec::new();
-    let mut as_mut_arms = Vec::new();
    let mut span_arms = Vec::new();
    let mut from_impls = Vec::new();
    let mut to_trait_impls = Vec::new();
@@ -109,19 +133,15 @@ pub fn ir_impl(input: TokenStream) -> TokenStream {
                });

                enum_variants.push(quote! { #name(#inner_type) });
-                ref_variants.push(quote! { #name(&'a #inner_type) });
-                mut_variants.push(quote! { #name(&'a mut #inner_type) });
-                as_ref_arms.push(quote! { Self::#name(inner) => #ref_name::#name(inner) });
-                as_mut_arms.push(quote! { Self::#name(inner) => #mut_name::#name(inner) });
                span_arms.push(quote! { Self::#name(inner) => inner.span });
                from_impls.push(quote! {
-                    impl From<#inner_type> for #base_name {
+                    impl <#generic_params> From<#inner_type> for #base_name <#generic_args> #where_clause {
                        fn from(val: #inner_type) -> Self { #base_name::#name(val) }
                    }
                });
                to_trait_impls.push(quote! {
-                    impl #to_trait_name for #name {
-                        fn #to_trait_fn_name(self) -> #base_name { #base_name::from(self) }
+                    impl <#generic_params> #to_trait_name <#generic_args> for #name #where_clause {
+                        fn #to_trait_fn_name(self) -> #base_name <#generic_args> { #base_name::from(self) }
                    }
                });
            }
@@ -138,25 +158,24 @@ pub fn ir_impl(input: TokenStream) -> TokenStream {

                let inner_type = name.clone();
                enum_variants.push(quote! { #name(#inner_type) });
-                ref_variants.push(quote! { #name(&'a #inner_type) });
-                mut_variants.push(quote! { #name(&'a mut #inner_type) });
-                as_ref_arms.push(quote! { Self::#name(inner) => #ref_name::#name(inner) });
-                as_mut_arms.push(quote! { Self::#name(inner) => #mut_name::#name(inner) });
                span_arms.push(quote! { Self::#name(inner) => inner.span });
                from_impls.push(quote! {
-                    impl From<#inner_type> for #base_name {
+                    impl <#generic_params> From<#inner_type> for #base_name <#generic_args> #where_clause {
                        fn from(val: #inner_type) -> Self { #base_name::#name(val) }
                    }
                });
                to_trait_impls.push(quote! {
-                    impl #to_trait_name for #name {
-                        fn #to_trait_fn_name(self) -> #base_name { #base_name::from(self) }
+                    impl <#generic_params> #to_trait_name <#generic_args> for #name #where_clause {
+                        fn #to_trait_fn_name(self) -> #base_name <#generic_args> { #base_name::from(self) }
                    }
                });
            }
            VariantInput::Struct(name, mut fields) => {
                let inner_type = name.clone();

+                fields.named.iter_mut().for_each(|field| {
+                    field.vis = syn::Visibility::Public(syn::token::Pub::default());
+                });
                fields.named.push(syn::Field {
                    attrs: vec![],
                    vis: syn::Visibility::Public(syn::token::Pub::default()),
@@ -168,22 +187,18 @@ pub fn ir_impl(input: TokenStream) -> TokenStream {

                struct_defs.push(quote! {
                    #[derive(Debug)]
-                    pub struct #name #fields
+                    pub struct #name <#generic_params> #where_clause #fields
                });
-                enum_variants.push(quote! { #name(#inner_type) });
-                ref_variants.push(quote! { #name(&'a #inner_type) });
-                mut_variants.push(quote! { #name(&'a mut #inner_type) });
-                as_ref_arms.push(quote! { Self::#name(inner) => #ref_name::#name(inner) });
-                as_mut_arms.push(quote! { Self::#name(inner) => #mut_name::#name(inner) });
+                enum_variants.push(quote! { #name(#inner_type <#generic_args>) });
                span_arms.push(quote! { Self::#name(inner) => inner.span });
                from_impls.push(quote! {
-                    impl From<#inner_type> for #base_name {
-                        fn from(val: #inner_type) -> Self { #base_name::#name(val) }
+                    impl <#generic_params> From<#inner_type <#generic_args>> for #base_name <#generic_args> #where_clause {
+                        fn from(val: #inner_type <#generic_args>) -> Self { #base_name::#name(val) }
                    }
                });
                to_trait_impls.push(quote! {
-                    impl #to_trait_name for #name {
-                        fn #to_trait_fn_name(self) -> #base_name { #base_name::from(self) }
+                    impl <#generic_params> #to_trait_name <#generic_args> for #name <#generic_args> #where_clause {
+                        fn #to_trait_fn_name(self) -> #base_name <#generic_args> { #base_name::from(self) }
                    }
                });
            }
@@ -193,41 +208,15 @@ pub fn ir_impl(input: TokenStream) -> TokenStream {
    // Assemble the final generated code.
    let expanded = quote! {
        /// The main IR enum, generated by the `ir!` macro.
-        #[derive(Debug, IsVariant, Unwrap, TryUnwrap)]
-        pub enum #base_name {
+        #[derive(Debug)]
+        pub enum #base_name <#generic_params> #where_clause {
            #( #enum_variants ),*
        }

        // The struct definitions for the enum variants.
        #( #struct_defs )*

-        /// An immutable reference version of the IR enum.
-        #[derive(Debug, IsVariant, Unwrap, TryUnwrap)]
-        pub enum #ref_name<'a> {
-            #( #ref_variants ),*
-        }
-
-        /// A mutable reference version of the IR enum.
-        #[derive(Debug, IsVariant, Unwrap, TryUnwrap)]
-        pub enum #mut_name<'a> {
-            #( #mut_variants ),*
-        }
-
-        impl #base_name {
-            /// Converts a `&Ir` into a `IrRef`.
-            pub fn as_ref(&self) -> #ref_name<'_> {
-                match self {
-                    #( #as_ref_arms ),*
-                }
-            }
-
-            /// Converts a `&mut Ir` into a `IrMut`.
-            pub fn as_mut(&mut self) -> #mut_name<'_> {
-                match self {
-                    #( #as_mut_arms ),*
-                }
-            }
-
+        impl <#generic_params> #base_name <#generic_args> #where_clause {
            pub fn span(&self) -> rnix::TextRange {
                match self {
                    #( #span_arms ),*
@@ -239,9 +228,9 @@ pub fn ir_impl(input: TokenStream) -> TokenStream {
        #( #from_impls )*

        /// A trait for converting a variant struct into the main IR enum.
-        pub trait #to_trait_name {
+        pub trait #to_trait_name <#generic_params> #where_clause {
            /// Performs the conversion.
-            fn #to_trait_fn_name(self) -> #base_name;
+            fn #to_trait_fn_name(self) -> #base_name <#generic_args>;
        }

        // Implement the `ToIr` trait for each variant struct.
--- a/nix-js/Cargo.toml
+++ b/nix-js/Cargo.toml
@@ -14,6 +14,9 @@ nix-compat = { git = "https://git.snix.dev/snix/snix.git", version = "0.1.0", fe
 anyhow = "1.0"
 rustyline = "17.0"

+# CLI
+clap = { version = "4", features = ["derive"] }
+
 # Logging
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
@@ -24,6 +27,7 @@ miette = { version = "7.4", features = ["fancy"] }

 hashbrown = "0.16"
 string-interner = "0.19"
+bumpalo = { version = "3.20", features = ["allocator-api2", "boxed", "collections"] }

 rust-embed="8.11"

@@ -36,6 +40,8 @@ deno_error = "0.7"

 nix-nar = "0.3"
 sha2 = "0.10"
+sha1 = "0.10"
+md5 = "0.8"
 hex = "0.4"

 base64 = "0.22"
@@ -53,7 +59,7 @@ dirs = "6.0"
 tempfile = "3.24"
 rusqlite = { version = "0.38", features = ["bundled"] }

-rnix = "0.13"
+rnix = "0.14"
 rowan = "0.16"

 nix-js-macros = { path = "../nix-js-macros" }
@@ -61,8 +67,23 @@ ere = "0.2.4"
 num_enum = "0.7.5"
 tap = "1.0.1"

+# Inspector (optional)
+fastwebsockets = { version = "0.10", features = ["upgrade"], optional = true }
+hyper = { version = "1", features = ["http1", "server"], optional = true }
+hyper-util = { version = "0.1", features = ["tokio"], optional = true }
+http-body-util = { version = "0.1", optional = true }
+http = { version = "1", optional = true }
+uuid = { version = "1", features = ["v4"], optional = true }
+ghost-cell = "0.2.6"
+colored = "3.1.1"
+
+[features]
+inspector = ["dep:fastwebsockets", "dep:hyper", "dep:hyper-util", "dep:http-body-util", "dep:http", "dep:uuid"]
+prof = []
+
 [dev-dependencies]
 criterion = { version = "0.8", features = ["html_reports"] }
+test-log = { version = "0.2", features = ["trace"] }

 [[bench]]
 name = "basic_ops"
--- a/nix-js/benches/basic_ops.rs
+++ b/nix-js/benches/basic_ops.rs
@@ -1,7 +1,8 @@
 mod utils;

-use criterion::{Criterion, criterion_group, criterion_main};
 use std::hint::black_box;
+
+use criterion::{Criterion, criterion_group, criterion_main};
 use utils::eval;

 fn bench_arithmetic(c: &mut Criterion) {
--- a/nix-js/benches/builtins.rs
+++ b/nix-js/benches/builtins.rs
@@ -1,7 +1,8 @@
 mod utils;

-use criterion::{Criterion, criterion_group, criterion_main};
 use std::hint::black_box;
+
+use criterion::{Criterion, criterion_group, criterion_main};
 use utils::eval;

 fn bench_builtin_math(c: &mut Criterion) {
--- a/nix-js/benches/compile_time.rs
+++ b/nix-js/benches/compile_time.rs
@@ -1,8 +1,9 @@
 mod utils;

+use std::hint::black_box;
+
 use criterion::{Criterion, criterion_group, criterion_main};
 use nix_js::context::Context;
-use std::hint::black_box;
 use utils::compile;

 fn bench_parse_and_downgrade(c: &mut Criterion) {
--- a/nix-js/benches/thunk_scope.rs
+++ b/nix-js/benches/thunk_scope.rs
@@ -1,7 +1,8 @@
 mod utils;

-use criterion::{Criterion, criterion_group, criterion_main};
 use std::hint::black_box;
+
+use criterion::{Criterion, criterion_group, criterion_main};
 use utils::eval;

 fn bench_non_recursive(c: &mut Criterion) {
--- a/nix-js/runtime-ts/eslint.config.mts
+++ b/nix-js/runtime-ts/eslint.config.mts
@@ -0,0 +1,20 @@
+import js from "@eslint/js";
+import { defineConfig } from "eslint/config";
+import globals from "globals";
+import tseslint from "typescript-eslint";
+
+export default defineConfig([
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    files: ["**/*.{js,mjs,cjs,ts,mts,cts}"],
+    languageOptions: { globals: globals.es2022 },
+    rules: {
+      "no-unused-vars": "off",
+      "@typescript-eslint/no-unused-vars": ["error", { varsIgnorePattern: "^_", argsIgnorePattern: "^_" }],
+    },
+  },
+  {
+    ignores: ["dist/**/*"],
+  },
+]);
--- a/nix-js/runtime-ts/package-lock.json
+++ b/nix-js/runtime-ts/package-lock.json
--- a/nix-js/runtime-ts/package.json
+++ b/nix-js/runtime-ts/package.json
@@ -3,15 +3,20 @@
  "version": "0.1.0",
  "private": true,
  "scripts": {
+    "check": "tsc --noEmit && npx eslint && biome check",
    "typecheck": "tsc --noEmit",
    "build": "node build.mjs",
    "dev": "npm run typecheck && npm run build"
  },
  "devDependencies": {
    "esbuild": "^0.24.2",
-    "typescript": "^5.7.2"
+    "eslint": "^9.39.2",
+    "typescript": "^5.7.2",
+    "typescript-eslint": "^8.55.0",
+    "jiti": "^2.6.1"
  },
  "dependencies": {
+    "globals": "^17.3.0",
    "js-sdsl": "^4.4.2"
  }
 }
--- a/nix-js/runtime-ts/src/builtins/arithmetic.ts
+++ b/nix-js/runtime-ts/src/builtins/arithmetic.ts
@@ -1,30 +1,26 @@
-/**
- * Arithmetic builtin functions
- */
-
-import type { NixBool, NixInt, NixNumber, NixValue } from "../types";
-import { forceNumeric, coerceNumeric, forceInt } from "../type-assert";
 import { op } from "../operators";
+import { coerceNumeric, forceInt, forceNumeric } from "../type-assert";
+import type { NixBool, NixInt, NixNumber, NixValue } from "../types";

 export const add =
  (a: NixValue) =>
  (b: NixValue): bigint | number => {
    const [av, bv] = coerceNumeric(forceNumeric(a), forceNumeric(b));
-    return (av as any) + (bv as any);
+    return (av as never) + (bv as never);
  };

 export const sub =
  (a: NixValue) =>
  (b: NixValue): bigint | number => {
    const [av, bv] = coerceNumeric(forceNumeric(a), forceNumeric(b));
-    return (av as any) - (bv as any);
+    return (av as never) - (bv as never);
  };

 export const mul =
  (a: NixValue) =>
  (b: NixValue): bigint | number => {
    const [av, bv] = coerceNumeric(forceNumeric(a), forceNumeric(b));
-    return (av as any) * (bv as any);
+    return (av as never) * (bv as never);
  };

 export const div =
@@ -36,10 +32,9 @@ export const div =
      throw new RangeError("Division by zero");
    }

-    return (av as any) / (bv as any);
+    return (av as never) / (bv as never);
  };

-// Bitwise operations - only for integers
 export const bitAnd =
  (a: NixValue) =>
  (b: NixValue): NixInt => {
--- a/nix-js/runtime-ts/src/builtins/attrs.ts
+++ b/nix-js/runtime-ts/src/builtins/attrs.ts
@@ -1,15 +1,12 @@
-/**
- * Attribute set operation builtin functions
- */
-
-import type { NixValue, NixAttrs, NixList } from "../types";
-import { forceAttrs, forceStringValue, forceFunction, forceList } from "../type-assert";
+import { mkPos, select } from "../helpers";
 import { createThunk } from "../thunk";
+import { forceAttrs, forceFunction, forceList, forceStringValue } from "../type-assert";
+import { ATTR_POSITIONS, type NixAttrs, type NixList, type NixValue } from "../types";

-export const attrNames = (set: NixValue): string[] => Object.keys(forceAttrs(set)).sort();
+export const attrNames = (set: NixValue): string[] => Array.from(forceAttrs(set).keys()).sort();

 export const attrValues = (set: NixValue): NixValue[] =>
-  Object.entries(forceAttrs(set))
+  Array.from(forceAttrs(set).entries())
    .sort(([a], [b]) => {
      if (a < b) {
        return -1;
@@ -24,21 +21,24 @@ export const attrValues = (set: NixValue): NixValue[] =>
 export const getAttr =
  (s: NixValue) =>
  (set: NixValue): NixValue =>
-    forceAttrs(set)[forceStringValue(s)];
+    select(forceAttrs(set), [s]);

 export const hasAttr =
  (s: NixValue) =>
  (set: NixValue): boolean =>
-    Object.hasOwn(forceAttrs(set), forceStringValue(s));
+    forceAttrs(set).has(forceStringValue(s));

 export const mapAttrs =
  (f: NixValue) =>
  (attrs: NixValue): NixAttrs => {
    const forcedAttrs = forceAttrs(attrs);
    const forcedF = forceFunction(f);
-    const newAttrs: NixAttrs = {};
-    for (const key in forcedAttrs) {
-      newAttrs[key] = createThunk(() => forceFunction(forcedF(key))(forcedAttrs[key]), "created by mapAttrs");
+    const newAttrs: NixAttrs = new Map();
+    for (const [key, val] of forcedAttrs) {
+      newAttrs.set(
+        key,
+        createThunk(() => forceFunction(forcedF(key))(val), "created by mapAttrs"),
+      );
    }
    return newAttrs;
  };
@@ -46,25 +46,20 @@ export const mapAttrs =
 export const removeAttrs =
  (attrs: NixValue) =>
  (list: NixValue): NixAttrs => {
-    const new_attrs: NixAttrs = {};
-    const forced_attrs = forceAttrs(attrs);
-    const forced_list = forceList(list);
-    const keys_to_remove = new Set(forced_list.map(forceStringValue));
-
-    for (const key in forced_attrs) {
-      if (!keys_to_remove.has(key)) {
-        new_attrs[key] = forced_attrs[key];
+    const newAttrs: NixAttrs = new Map(forceAttrs(attrs));
+    const forcedList = forceList(list);
+    for (const item of forcedList) {
+      newAttrs.delete(forceStringValue(item));
    }
-    }
-    return new_attrs;
+    return newAttrs;
  };

 export const listToAttrs = (e: NixValue): NixAttrs => {
-  const attrs: NixAttrs = {};
-  const forced_e = [...forceList(e)].reverse();
-  for (const obj of forced_e) {
+  const attrs: NixAttrs = new Map();
+  const forcedE = [...forceList(e)].reverse();
+  for (const obj of forcedE) {
    const item = forceAttrs(obj);
-    attrs[forceStringValue(item.name)] = item.value;
+    attrs.set(forceStringValue(select(item, ["name"])), select(item, ["value"]));
  }
  return attrs;
 };
@@ -74,10 +69,18 @@ export const intersectAttrs =
  (e2: NixValue): NixAttrs => {
    const f1 = forceAttrs(e1);
    const f2 = forceAttrs(e2);
-    const attrs: NixAttrs = {};
-    for (const key of Object.keys(f2)) {
-      if (Object.hasOwn(f1, key)) {
-        attrs[key] = f2[key];
+    const attrs: NixAttrs = new Map();
+    if (f1.size < f2.size) {
+      for (const [key] of f1) {
+        if (f2.has(key)) {
+          attrs.set(key, f2.get(key) as NixValue);
+        }
+      }
+    } else {
+      for (const [key] of f2) {
+        if (f1.has(key)) {
+          attrs.set(key, f2.get(key) as NixValue);
+        }
      }
    }
    return attrs;
@@ -88,20 +91,20 @@ export const catAttrs =
  (list: NixValue): NixList => {
    const key = forceStringValue(attr);
    return forceList(list)
-      .map((set) => forceAttrs(set)[key])
-      .filter((val) => val !== undefined);
+      .map((set) => forceAttrs(set).get(key))
+      .filter((val) => val !== undefined) as NixList;
  };

 export const groupBy =
  (f: NixValue) =>
  (list: NixValue): NixAttrs => {
-    const attrs: NixAttrs = {};
-    const forced_f = forceFunction(f);
-    const forced_list = forceList(list);
-    for (const elem of forced_list) {
-      const key = forceStringValue(forced_f(elem));
-      if (!attrs[key]) attrs[key] = [];
-      (attrs[key] as NixList).push(elem);
+    const attrs: NixAttrs = new Map();
+    const forcedF = forceFunction(f);
+    const forcedList = forceList(list);
+    for (const elem of forcedList) {
+      const key = forceStringValue(forcedF(elem));
+      if (!attrs.has(key)) attrs.set(key, []);
+      (attrs.get(key) as NixList).push(elem);
    }
    return attrs;
  };
@@ -111,29 +114,26 @@ export const zipAttrsWith =
  (list: NixValue): NixValue => {
    const listForced = forceList(list);

-    // Map to collect all values for each attribute name
    const attrMap = new Map<string, NixValue[]>();

-    // Iterate through each attribute set in the list
    for (const item of listForced) {
      const attrs = forceAttrs(item);

-      // Collect all attribute names and their values
-      for (const [key, value] of Object.entries(attrs)) {
+      for (const [key, value] of attrs) {
        if (!attrMap.has(key)) {
          attrMap.set(key, []);
        }
-        attrMap.get(key)!.push(value);
+        (attrMap.get(key) as NixValue[]).push(value);
      }
    }

-    // Build the result attribute set
-    const result: Record<string, NixValue> = {};
+    const result: NixAttrs = new Map();

    for (const [name, values] of attrMap.entries()) {
-      // Apply f to name and values list
-      // f is curried: f name values
-      result[name] = createThunk(() => forceFunction(forceFunction(f)(name))(values));
+      result.set(
+        name,
+        createThunk(() => forceFunction(forceFunction(f)(name))(values)),
+      );
    }

    return result;
@@ -145,15 +145,15 @@ export const unsafeGetAttrPos =
    const name = forceStringValue(attrName);
    const attrs = forceAttrs(attrSet);

-    if (!(name in attrs)) {
+    if (!attrs.has(name)) {
      return null;
    }

-    const positions = (attrs as any)[Nix.ATTR_POSITIONS];
-    if (!positions || !(name in positions)) {
+    const positions = attrs[ATTR_POSITIONS];
+    if (!positions || !positions.has(name)) {
      return null;
    }

-    const span = positions[name];
-    return Nix.mkPos(span);
+    const span = positions.get(name) as number;
+    return mkPos(span);
  };
--- a/nix-js/runtime-ts/src/builtins/context.ts
+++ b/nix-js/runtime-ts/src/builtins/context.ts
@@ -1,15 +1,15 @@
-import type { NixValue, NixAttrs, NixString } from "../types";
-import { isStringWithContext } from "../types";
-import { forceString, forceAttrs, forceList, forceStringValue } from "../type-assert";
-import { force } from "../thunk";
 import {
-  type NixStringContext,
-  getStringValue,
-  getStringContext,
-  mkStringWithContext,
  decodeContextElem,
+  getStringContext,
+  getStringValue,
+  mkStringWithContext,
+  type NixStringContext,
  parseContextToInfoMap,
 } from "../string-context";
+import { force } from "../thunk";
+import { forceAttrs, forceList, forceString, forceStringValue } from "../type-assert";
+import type { NixAttrs, NixString, NixValue } from "../types";
+import { isStringWithContext } from "../types";

 /**
 * builtins.hasContext - Check if string has context
@@ -113,20 +113,20 @@ export const getContext = (value: NixValue): NixAttrs => {
  const context = getStringContext(s);

  const infoMap = parseContextToInfoMap(context);
-  const result: NixAttrs = {};
+  const result: NixAttrs = new Map();

  for (const [path, info] of infoMap) {
-    const attrs: NixAttrs = {};
+    const attrs: NixAttrs = new Map();
    if (info.path) {
-      attrs["path"] = true;
+      attrs.set("path", true);
    }
    if (info.allOutputs) {
-      attrs["allOutputs"] = true;
+      attrs.set("allOutputs", true);
    }
    if (info.outputs.length > 0) {
-      attrs["outputs"] = info.outputs;
+      attrs.set("outputs", info.outputs);
    }
-    result[path] = attrs;
+    result.set(path, attrs);
  }

  return result;
@@ -154,22 +154,22 @@ export const appendContext =
    const ctxAttrs = forceAttrs(ctxValue);
    const newContext: NixStringContext = new Set(existingContext);

-    for (const [path, infoVal] of Object.entries(ctxAttrs)) {
+    for (const [path, infoVal] of ctxAttrs) {
      if (!path.startsWith("/nix/store/")) {
        throw new Error(`context key '${path}' is not a store path`);
      }

-      const info = forceAttrs(infoVal);
+      const info = forceAttrs(infoVal as NixValue);

-      if ("path" in info) {
-        const pathVal = force(info["path"]);
+      if (info.has("path")) {
+        const pathVal = force(info.get("path") as NixValue);
        if (pathVal === true) {
          newContext.add(path);
        }
      }

-      if ("allOutputs" in info) {
-        const allOutputs = force(info["allOutputs"]);
+      if (info.has("allOutputs")) {
+        const allOutputs = force(info.get("allOutputs") as NixValue);
        if (allOutputs === true) {
          if (!path.endsWith(".drv")) {
            throw new Error(
@@ -180,8 +180,8 @@ export const appendContext =
        }
      }

-      if ("outputs" in info) {
-        const outputs = forceList(info["outputs"]);
+      if (info.has("outputs")) {
+        const outputs = forceList(info.get("outputs") as NixValue);
        if (outputs.length > 0 && !path.endsWith(".drv")) {
          throw new Error(
            `tried to add derivation output context of ${path}, which is not a derivation, to a string`,
--- a/nix-js/runtime-ts/src/builtins/conversion.ts
+++ b/nix-js/runtime-ts/src/builtins/conversion.ts
@@ -2,12 +2,16 @@
 * Conversion and serialization builtin functions
 */

-import type { NixString, NixValue } from "../types";
-import { isStringWithContext, isNixPath } from "../types";
-import { force } from "../thunk";
-import { type NixStringContext, mkStringWithContext, addBuiltContext } from "../string-context";
+import {
+  addBuiltContext,
+  mkStringWithContext,
+  type NixStringContext,
+  StringWithContext,
+} from "../string-context";
+import { force, isThunk } from "../thunk";
 import { forceFunction, forceStringNoCtx } from "../type-assert";
-import { nixValueToJson } from "../conversion";
+import type { NixString, NixValue } from "../types";
+import { isNixPath, isStringWithContext, NixPath } from "../types";
 import { isAttrs, isPath, typeOf } from "./type-check";

 export const fromJSON = (e: NixValue): NixValue => {
@@ -16,12 +20,12 @@ export const fromJSON = (e: NixValue): NixValue => {
    throw new TypeError(`builtins.fromJSON: expected a string, got ${typeOf(str)}`);
  }
  const jsonStr = isStringWithContext(str) ? str.value : str;
-  return Deno.core.ops.op_from_json(jsonStr);
+  return Deno.core.ops.op_from_json(jsonStr) as NixValue;
 };

 export const fromTOML = (e: NixValue): NixValue => {
  const toml = forceStringNoCtx(e);
-  return Deno.core.ops.op_from_toml(toml);
+  return Deno.core.ops.op_from_toml(toml) as NixValue;
 };

 export const toJSON = (e: NixValue): NixString => {
@@ -33,8 +37,12 @@ export const toJSON = (e: NixValue): NixString => {
  return mkStringWithContext(string, context);
 };

-export const toXML = (e: NixValue): never => {
-  throw new Error("Not implemented: toXML");
+export const toXML = (e: NixValue): NixString => {
+  const [xml, context] = Deno.core.ops.op_to_xml(force(e));
+  if (context.length === 0) {
+    return xml;
+  }
+  return mkStringWithContext(xml, new Set(context));
 };

 /**
@@ -87,7 +95,7 @@ export const coerceToString = (
  value: NixValue,
  mode: StringCoercionMode,
  copyToStore: boolean = false,
-  outContext?: NixStringContext,
+  outContext: NixStringContext,
 ): string => {
  const v = force(value);

@@ -97,11 +105,9 @@ export const coerceToString = (
  }

  if (isStringWithContext(v)) {
-    if (outContext) {
    for (const elem of v.context) {
      outContext.add(elem);
    }
-    }
    return v.value;
  }

@@ -110,46 +116,38 @@ export const coerceToString = (
    if (copyToStore) {
      const pathStr = v.value;
      const storePath = Deno.core.ops.op_copy_path_to_store(pathStr);
-      if (outContext) {
      outContext.add(storePath);
-      }
      return storePath;
    }
    return v.value;
  }

  if (typeof v === "object" && v !== null && !Array.isArray(v)) {
-    // First, try the __toString method if present
-    // This allows custom types to define their own string representation
-    if ("__toString" in v) {
-      // Force the method in case it's a thunk
-      const toStringMethod = forceFunction(v.__toString);
+    if (v instanceof Map) {
+      if (v.has("__toString")) {
+        const toStringMethod = forceFunction(v.get("__toString") as NixValue);
        const result = force(toStringMethod(v));
-      // Recursively coerceToString
        return coerceToString(result, mode, copyToStore, outContext);
      }

-    // If no __toString, try outPath (used for derivations and store paths)
-    // This allows derivation objects like { outPath = "/nix/store/..."; } to be coerced
-    if ("outPath" in v) {
-      // Recursively coerce the outPath value
-      const outPath = coerceToString(v.outPath, mode, copyToStore, outContext);
-      if ("type" in v && v.type === "derivation" && "drvPath" in v && outContext) {
-        const drvPathValue = force(v.drvPath);
+      if (v.has("outPath")) {
+        const outPath = coerceToString(v.get("outPath") as NixValue, mode, copyToStore, outContext);
+        if (v.has("type") && v.get("type") === "derivation" && v.has("drvPath") && outContext) {
+          const drvPathValue = force(v.get("drvPath") as NixValue);
          const drvPathStr = isStringWithContext(drvPathValue)
            ? drvPathValue.value
            : typeof drvPathValue === "string"
              ? drvPathValue
              : null;
          if (drvPathStr) {
-          const outputName = "outputName" in v ? String(force(v.outputName)) : "out";
+            const outputName = v.has("outputName") ? String(force(v.get("outputName") as NixValue)) : "out";
            addBuiltContext(outContext, drvPathStr, outputName);
          }
        }
        return outPath;
      }
+    }

-    // Attribute sets without __toString or outPath cannot be coerced
    throw new TypeError(`cannot coerce ${typeOf(v)} to a string`);
  }

@@ -254,14 +252,14 @@ export const coerceToStringWithContext = (
 * - Returns the path string (not a NixPath object)
 * - Preserves string context if present
 */
-export const coerceToPath = (value: NixValue, outContext?: NixStringContext): string => {
+export const coerceToPath = (value: NixValue, outContext: NixStringContext): string => {
  const forced = force(value);

  if (isPath(forced)) {
    return forced.value;
  }
-  if (isAttrs(forced) && Object.hasOwn(forced, "__toString")) {
-    const toStringFunc = forceFunction(forced.__toString);
+  if (isAttrs(forced) && forced.has("__toString")) {
+    const toStringFunc = forceFunction(forced.get("__toString") as NixValue);
    return coerceToPath(toStringFunc(forced), outContext);
  }

@@ -290,3 +288,84 @@ export const coerceToPath = (value: NixValue, outContext?: NixStringContext): st
 export const toStringFunc = (value: NixValue): NixString => {
  return coerceToStringWithContext(value, StringCoercionMode.ToString, false);
 };
+
+export type JsonValue = number | boolean | string | null | { [key: string]: JsonValue } | Array<JsonValue>;
+export const nixValueToJson = (
+  value: NixValue,
+  strict: boolean,
+  outContext: NixStringContext,
+  copyToStore: boolean,
+  seen: Set<NixValue> = new Set(),
+): JsonValue => {
+  const v = strict ? force(value) : value;
+
+  if (isThunk(v) || typeof v === "function")
+    throw new Error(`cannot convert ${isThunk(v) ? "thunk" : "lambda"} to JSON`);
+  if (v === null) return null;
+  if (typeof v === "bigint") {
+    const num = Number(v);
+    if (v > Number.MAX_SAFE_INTEGER || v < Number.MIN_SAFE_INTEGER) {
+      console.warn(`integer ${v} exceeds safe range, precision may be lost`);
+    }
+    return num;
+  }
+  if (typeof v === "number") return v;
+  if (typeof v === "boolean") return v;
+  if (typeof v === "string") return v;
+  if (v instanceof StringWithContext) {
+    for (const elem of v.context) {
+      outContext.add(elem);
+    }
+    return v.value;
+  }
+  if (v instanceof NixPath) {
+    if (copyToStore) {
+      const storePath = Deno.core.ops.op_copy_path_to_store(v.value);
+      outContext.add(storePath);
+      return storePath;
+    } else {
+      return v.value;
+    }
+  }
+
+  // FIXME: is this check necessary?
+  // if (seen.has(v)) {
+  //   throw new Error("cycle detected in toJSON");
+  // } else {
+  //   seen.add(v)
+  // }
+
+  if (Array.isArray(v)) {
+    return v.map((item) => nixValueToJson(item, strict, outContext, copyToStore, seen));
+  }
+
+  if (v instanceof Map) {
+    if (v.has("__toString") && typeof force(v.get("__toString") as NixValue) === "function") {
+      const toStringMethod = force(v.get("__toString") as NixValue) as (self: typeof v) => NixValue;
+      const result = force(toStringMethod(v));
+      if (typeof result === "string") {
+        return result;
+      }
+      if (isStringWithContext(result)) {
+        for (const elem of result.context) {
+          outContext.add(elem);
+        }
+        return result.value;
+      }
+      return nixValueToJson(result, strict, outContext, copyToStore, seen);
+    }
+
+    if (v.has("outPath")) {
+      return nixValueToJson(v.get("outPath") as NixValue, strict, outContext, copyToStore, seen);
+    }
+
+    const result: { [key: string]: JsonValue } = {};
+    const keys = Array.from(v.keys()).sort();
+    for (const key of keys) {
+      result[key] = nixValueToJson(v.get(key) as NixValue, strict, outContext, copyToStore, seen);
+    }
+    return result;
+  }
+
+  throw new Error(`cannot convert ${typeof v} to JSON`);
+};
--- a/nix-js/runtime-ts/src/builtins/derivation.ts
+++ b/nix-js/runtime-ts/src/builtins/derivation.ts
@@ -1,45 +1,125 @@
-import type { NixValue, NixAttrs } from "../types";
-import { forceStringValue, forceList, forceStringNoCtx } from "../type-assert";
-import { force } from "../thunk";
 import {
-  type DerivationData,
-  type OutputInfo,
-  generateAterm,
-  generateAtermModulo,
-} from "../derivation-helpers";
-import { coerceToString, StringCoercionMode } from "./conversion";
-import {
-  type NixStringContext,
-  extractInputDrvsAndSrcs,
-  isStringWithContext,
-  mkStringWithContext,
-  addDrvDeepContext,
  addBuiltContext,
+  addDrvDeepContext,
+  mkStringWithContext,
+  type NixStringContext,
 } from "../string-context";
-import { nixValueToJson } from "../conversion";
-import { isNixPath } from "../types";
+import { force } from "../thunk";
+import { forceAttrs, forceList, forceStringNoCtx, forceStringValue } from "../type-assert";
+import type { NixAttrs, NixValue } from "../types";
+import { coerceToString, type JsonValue, nixValueToJson, StringCoercionMode } from "./conversion";

-const drvHashCache = new Map<string, string>();
-
-const forceAttrs = (value: NixValue): NixAttrs => {
-  const forced = force(value);
-  if (
-    typeof forced !== "object" ||
-    forced === null ||
-    Array.isArray(forced) ||
-    isStringWithContext(forced) ||
-    isNixPath(forced)
-  ) {
-    throw new TypeError(`Expected attribute set for derivation, got ${typeof forced}`);
+export interface OutputInfo {
+  path: string;
+  hashAlgo: string;
+  hash: string;
 }
-  return forced;
+
+export interface DerivationData {
+  name: string;
+  outputs: Map<string, OutputInfo>;
+  inputDrvs: Map<string, Set<string>>;
+  inputSrcs: Set<string>;
+  platform: string;
+  builder: string;
+  args: string[];
+  env: Map<string, string>;
+}
+
+export const escapeString = (s: string): string => {
+  let result = "";
+  for (const char of s) {
+    switch (char) {
+      case '"':
+        result += '\\"';
+        break;
+      case "\\":
+        result += "\\\\";
+        break;
+      case "\n":
+        result += "\\n";
+        break;
+      case "\r":
+        result += "\\r";
+        break;
+      case "\t":
+        result += "\\t";
+        break;
+      default:
+        result += char;
+    }
+  }
+  return `"${result}"`;
 };

+const quoteString = (s: string): string => `"${s}"`;
+
+const cmpByKey = <T>(a: [string, T], b: [string, T]): number => (a[0] < b[0] ? -1 : a[0] > b[0] ? 1 : 0);
+
+export const generateAterm = (drv: DerivationData): string => {
+  const outputEntries: string[] = [];
+  const sortedOutputs = Array.from(drv.outputs.entries()).sort(cmpByKey);
+  for (const [name, info] of sortedOutputs) {
+    outputEntries.push(
+      `(${quoteString(name)},${quoteString(info.path)},${quoteString(info.hashAlgo)},${quoteString(info.hash)})`,
+    );
+  }
+  const outputs = outputEntries.join(",");
+
+  const inputDrvEntries: string[] = [];
+  const sortedInputDrvs = Array.from(drv.inputDrvs.entries()).sort(cmpByKey);
+  for (const [drvPath, outputs] of sortedInputDrvs) {
+    const sortedOuts = Array.from(outputs).sort();
+    const outList = `[${sortedOuts.map(quoteString).join(",")}]`;
+    inputDrvEntries.push(`(${quoteString(drvPath)},${outList})`);
+  }
+  const inputDrvs = inputDrvEntries.join(",");
+
+  const sortedInputSrcs = Array.from(drv.inputSrcs).sort();
+  const inputSrcs = sortedInputSrcs.map(quoteString).join(",");
+
+  const args = drv.args.map(escapeString).join(",");
+  const envs = Array.from(drv.env.entries())
+    .sort(cmpByKey)
+    .map(([k, v]) => `(${escapeString(k)},${escapeString(v)})`);
+
+  return `Derive([${outputs}],[${inputDrvs}],[${inputSrcs}],${quoteString(drv.platform)},${escapeString(drv.builder)},[${args}],[${envs}])`;
+};
+
+export const generateAtermModulo = (drv: DerivationData, inputDrvHashes: Map<string, string>): string => {
+  const outputEntries: string[] = [];
+  const sortedOutputs = Array.from(drv.outputs.entries()).sort(cmpByKey);
+  for (const [name, info] of sortedOutputs) {
+    outputEntries.push(
+      `(${quoteString(name)},${quoteString(info.path)},${quoteString(info.hashAlgo)},${quoteString(info.hash)})`,
+    );
+  }
+  const outputs = outputEntries.join(",");
+
+  const inputDrvEntries: string[] = [];
+  const sortedInputDrvHashes = Array.from(inputDrvHashes.entries()).sort(cmpByKey);
+  for (const [drvHash, outputs] of sortedInputDrvHashes) {
+    const sortedOuts = outputs.split(",").sort();
+    const outList = `[${sortedOuts.map(quoteString).join(",")}]`;
+    inputDrvEntries.push(`(${quoteString(drvHash)},${outList})`);
+  }
+  const inputDrvs = inputDrvEntries.join(",");
+
+  const sortedInputSrcs = Array.from(drv.inputSrcs).sort();
+  const inputSrcs = sortedInputSrcs.map(quoteString).join(",");
+
+  const args = drv.args.map(escapeString).join(",");
+  const envs = Array.from(drv.env.entries())
+    .sort(cmpByKey)
+    .map(([k, v]) => `(${escapeString(k)},${escapeString(v)})`);
+
+  return `Derive([${outputs}],[${inputDrvs}],[${inputSrcs}],${quoteString(drv.platform)},${escapeString(drv.builder)},[${args}],[${envs}])`;
+};
 const validateName = (attrs: NixAttrs): string => {
-  if (!("name" in attrs)) {
+  if (!attrs.has("name")) {
    throw new Error("derivation: missing required attribute 'name'");
  }
-  const name = forceStringValue(attrs.name);
+  const name = forceStringValue(attrs.get("name") as NixValue);
  if (!name) {
    throw new Error("derivation: 'name' cannot be empty");
  }
@@ -50,17 +130,17 @@ const validateName = (attrs: NixAttrs): string => {
 };

 const validateBuilder = (attrs: NixAttrs, outContext: NixStringContext): string => {
-  if (!("builder" in attrs)) {
+  if (!attrs.has("builder")) {
    throw new Error("derivation: missing required attribute 'builder'");
  }
-  return coerceToString(attrs.builder, StringCoercionMode.ToString, true, outContext);
+  return coerceToString(attrs.get("builder") as NixValue, StringCoercionMode.ToString, true, outContext);
 };

 const validateSystem = (attrs: NixAttrs): string => {
-  if (!("system" in attrs)) {
+  if (!attrs.has("system")) {
    throw new Error("derivation: missing required attribute 'system'");
  }
-  return forceStringValue(attrs.system);
+  return forceStringValue(attrs.get("system") as NixValue);
 };

 const validateOutputs = (outputs: string[]): void => {
@@ -82,17 +162,25 @@ const validateOutputs = (outputs: string[]): void => {
 };

 const extractOutputs = (attrs: NixAttrs, structuredAttrs: boolean): string[] => {
-  if (!("outputs" in attrs)) {
+  if (!attrs.has("outputs")) {
    return ["out"];
  }

  let outputs: string[];
  if (structuredAttrs) {
-    const outputsList = forceList(attrs.outputs);
+    const outputsList = forceList(attrs.get("outputs") as NixValue);
    outputs = outputsList.map((o) => forceStringValue(o));
  } else {
-    const outputsStr = coerceToString(attrs.outputs, StringCoercionMode.ToString, false, new Set());
-    outputs = outputsStr.split(/\s+/).filter((s) => s.length > 0);
+    const outputsStr = coerceToString(
+      attrs.get("outputs") as NixValue,
+      StringCoercionMode.ToString,
+      false,
+      new Set(),
+    );
+    outputs = outputsStr
+      .trim()
+      .split(/\s+/)
+      .filter((s) => s.length > 0);
  }

  validateOutputs(outputs);
@@ -100,20 +188,13 @@ const extractOutputs = (attrs: NixAttrs, structuredAttrs: boolean): string[] =>
 };

 const extractArgs = (attrs: NixAttrs, outContext: NixStringContext): string[] => {
-  if (!("args" in attrs)) {
+  if (!attrs.has("args")) {
    return [];
  }
-  const argsList = forceList(attrs.args);
+  const argsList = forceList(attrs.get("args") as NixValue);
  return argsList.map((a) => coerceToString(a, StringCoercionMode.ToString, true, outContext));
 };

-const outputPathName = (drvName: string, output: string) => {
-  if (output === "out") {
-    return drvName
-  }
-  return `${drvName}-${output}`
-}
-
 const structuredAttrsExcludedKeys = new Set([
  "__structuredAttrs",
  "__ignoreNulls",
@@ -124,9 +205,9 @@ const structuredAttrsExcludedKeys = new Set([

 const specialAttrs = new Set(["args", "__ignoreNulls", "__contentAddressed", "__impure"]);

-const sortedJsonStringify = (obj: Record<string, any>): string => {
+const sortedJsonStringify = (obj: Record<string, JsonValue>): string => {
  const sortedKeys = Object.keys(obj).sort();
-  const sortedObj: Record<string, any> = {};
+  const sortedObj: Record<string, JsonValue> = {};
  for (const key of sortedKeys) {
    sortedObj[key] = obj[key];
  }
@@ -143,8 +224,8 @@ const extractEnv = (
  const env = new Map<string, string>();

  if (structuredAttrs) {
-    const jsonAttrs: Record<string, any> = {};
-    for (const [key, value] of Object.entries(attrs)) {
+    const jsonAttrs: Record<string, JsonValue> = {};
+    for (const [key, value] of attrs) {
      if (!structuredAttrsExcludedKeys.has(key)) {
        const forcedValue = force(value);
        if (ignoreNulls && forcedValue === null) {
@@ -198,13 +279,13 @@ const extractEnv = (
    }
    env.set("__json", sortedJsonStringify(jsonAttrs));
  } else {
-    for (const [key, value] of Object.entries(attrs)) {
+    for (const [key, value] of attrs) {
      if (!specialAttrs.has(key)) {
-        const forcedValue = force(value);
+        const forcedValue = force(value as NixValue);
        if (ignoreNulls && forcedValue === null) {
          continue;
        }
-        env.set(key, coerceToString(value, StringCoercionMode.ToString, true, outContext));
+        env.set(key, coerceToString(value as NixValue, StringCoercionMode.ToString, true, outContext));
      }
    }
  }
@@ -219,29 +300,29 @@ interface FixedOutputInfo {
 }

 const extractFixedOutputInfo = (attrs: NixAttrs, ignoreNulls: boolean): FixedOutputInfo | null => {
-  if (!("outputHash" in attrs)) {
+  if (!attrs.has("outputHash")) {
    return null;
  }

-  const hashValue = force(attrs.outputHash);
+  const hashValue = force(attrs.get("outputHash") as NixValue);
  if (ignoreNulls && hashValue === null) {
    return null;
  }
-  const hashRaw = forceStringNoCtx(attrs.outputHash);
+  const hashRaw = forceStringNoCtx(hashValue);

  let hashAlgo = null;
-  if ("outputHashAlgo" in attrs) {
-    const algoValue = force(attrs.outputHashAlgo);
+  if (attrs.has("outputHashAlgo")) {
+    const algoValue = force(attrs.get("outputHashAlgo") as NixValue);
    if (!(ignoreNulls && algoValue === null)) {
-      hashAlgo = forceStringNoCtx(attrs.outputHashAlgo);
+      hashAlgo = forceStringNoCtx(algoValue);
    }
  }

  let hashMode = "flat";
-  if ("outputHashMode" in attrs) {
-    const modeValue = force(attrs.outputHashMode);
+  if (attrs.has("outputHashMode")) {
+    const modeValue = force(attrs.get("outputHashMode") as NixValue);
    if (!(ignoreNulls && modeValue === null)) {
-      hashMode = forceStringValue(attrs.outputHashMode);
+      hashMode = forceStringValue(modeValue);
    }
  }

@@ -268,157 +349,60 @@ export const derivationStrict = (args: NixValue): NixAttrs => {
  const builder = validateBuilder(attrs, collectedContext);
  const platform = validateSystem(attrs);

-  const structuredAttrs = "__structuredAttrs" in attrs ? force(attrs.__structuredAttrs) === true : false;
-  const ignoreNulls = "__ignoreNulls" in attrs ? force(attrs.__ignoreNulls) === true : false;
+  const structuredAttrs = attrs.has("__structuredAttrs")
+    ? force(attrs.get("__structuredAttrs") as NixValue) === true
+    : false;
+  const ignoreNulls = attrs.has("__ignoreNulls")
+    ? force(attrs.get("__ignoreNulls") as NixValue) === true
+    : false;

  const outputs = extractOutputs(attrs, structuredAttrs);
  const fixedOutputInfo = extractFixedOutputInfo(attrs, ignoreNulls);
  validateFixedOutputConstraints(fixedOutputInfo, outputs);

-  if ("__contentAddressed" in attrs && force(attrs.__contentAddressed) === true) {
+  if (attrs.has("__contentAddressed") && force(attrs.get("__contentAddressed") as NixValue) === true) {
    throw new Error("ca derivations are not supported");
  }

-  if ("__impure" in attrs && force(attrs.__impure) === true) {
+  if (attrs.has("__impure") && force(attrs.get("__impure") as NixValue) === true) {
    throw new Error("impure derivations are not supported");
  }

  const drvArgs = extractArgs(attrs, collectedContext);
  const env = extractEnv(attrs, structuredAttrs, ignoreNulls, collectedContext, drvName);

-  const { inputDrvs, inputSrcs } = extractInputDrvsAndSrcs(collectedContext);
+  const envEntries: [string, string][] = Array.from(env.entries());
+  const contextArray: string[] = Array.from(collectedContext);

-  const collectDrvReferences = (): string[] => {
-    const refs = new Set<string>();
-    for (const src of inputSrcs) {
-      refs.add(src);
-    }
-    for (const drvPath of inputDrvs.keys()) {
-      refs.add(drvPath);
-    }
-    return Array.from(refs).sort();
-  };
-
-  let outputInfos: Map<string, OutputInfo>;
-  let drvPath: string;
-
-  if (fixedOutputInfo) {
-    const pathName = outputPathName(drvName, "out");
-    const outPath = Deno.core.ops.op_make_fixed_output_path(
-      fixedOutputInfo.hashAlgo,
-      fixedOutputInfo.hash,
-      fixedOutputInfo.hashMode,
-      pathName,
+  const rustResult: {
+    drvPath: string;
+    outputs: [string, string][];
+  } = Deno.core.ops.op_finalize_derivation(
+    drvName,
+    builder,
+    platform,
+    outputs,
+    drvArgs,
+    envEntries,
+    contextArray,
+    fixedOutputInfo,
  );

-    const hashAlgoPrefix = fixedOutputInfo.hashMode === "recursive" ? "r:" : "";
-    outputInfos = new Map([
-      [
-        "out",
-        {
-          path: outPath,
-          hashAlgo: hashAlgoPrefix + fixedOutputInfo.hashAlgo,
-          hash: fixedOutputInfo.hash,
-        },
-      ],
-    ]);
-    env.set("out", outPath);
-
-    const finalDrv: DerivationData = {
-      name: drvName,
-      outputs: outputInfos,
-      inputDrvs,
-      inputSrcs,
-      platform,
-      builder,
-      args: drvArgs,
-      env,
-    };
-    const finalAterm = generateAterm(finalDrv);
-    drvPath = Deno.core.ops.op_write_derivation(drvName, finalAterm, collectDrvReferences());
-
-    const fixedHashFingerprint = `fixed:out:${hashAlgoPrefix}${fixedOutputInfo.hashAlgo}:${fixedOutputInfo.hash}:${outPath}`;
-    const fixedModuloHash = Deno.core.ops.op_sha256_hex(fixedHashFingerprint);
-    drvHashCache.set(drvPath, fixedModuloHash);
-  } else {
-    const maskedOutputs = new Map<string, OutputInfo>(
-      outputs.map((o) => [
-        o,
-        {
-          path: "",
-          hashAlgo: "",
-          hash: "",
-        },
-      ]),
-    );
-    const maskedEnv = new Map(env);
-    for (const output of outputs) {
-      maskedEnv.set(output, "");
-    }
-
-    const maskedDrv: DerivationData = {
-      name: drvName,
-      outputs: maskedOutputs,
-      inputDrvs,
-      inputSrcs,
-      platform,
-      builder,
-      args: drvArgs,
-      env: maskedEnv,
-    };
-
-    const inputDrvHashes = new Map<string, string>();
-    for (const [drvPath, outputNames] of inputDrvs) {
-      const cachedHash = drvHashCache.get(drvPath);
-      if (!cachedHash) {
-        throw new Error(`Missing modulo hash for input derivation: ${drvPath}`);
-      }
-      inputDrvHashes.set(cachedHash, Array.from(outputNames).join(","));
-    }
-
-    const maskedAterm = generateAtermModulo(maskedDrv, inputDrvHashes);
-    const drvModuloHash = Deno.core.ops.op_sha256_hex(maskedAterm);
-
-    outputInfos = new Map<string, OutputInfo>();
-    for (const outputName of outputs) {
-      const pathName = outputPathName(drvName, outputName);
-      const outPath = Deno.core.ops.op_make_store_path(`output:${outputName}`, drvModuloHash, pathName);
-      outputInfos.set(outputName, {
-        path: outPath,
-        hashAlgo: "",
-        hash: "",
-      });
-      env.set(outputName, outPath);
-    }
-
-    const finalDrv: DerivationData = {
-      ...maskedDrv,
-      outputs: outputInfos,
-      env,
-    };
-    const finalAterm = generateAterm(finalDrv);
-    drvPath = Deno.core.ops.op_write_derivation(drvName, finalAterm, collectDrvReferences());
-
-    const finalAtermModulo = generateAtermModulo(finalDrv, inputDrvHashes);
-    const cachedModuloHash = Deno.core.ops.op_sha256_hex(finalAtermModulo);
-    drvHashCache.set(drvPath, cachedModuloHash);
-  }
-
-  const result: NixAttrs = {};
+  const result: NixAttrs = new Map();

  const drvPathContext = new Set<string>();
-  addDrvDeepContext(drvPathContext, drvPath);
-  result.drvPath = mkStringWithContext(drvPath, drvPathContext);
+  addDrvDeepContext(drvPathContext, rustResult.drvPath);
+  result.set("drvPath", mkStringWithContext(rustResult.drvPath, drvPathContext));

-  for (const [outputName, outputInfo] of outputInfos.entries()) {
+  for (const [outputName, outputPath] of rustResult.outputs) {
    const outputContext = new Set<string>();
-    addBuiltContext(outputContext, drvPath, outputName);
-    result[outputName] = mkStringWithContext(outputInfo.path, outputContext);
+    addBuiltContext(outputContext, rustResult.drvPath, outputName);
+    result.set(outputName, mkStringWithContext(outputPath, outputContext));
  }

  return result;
 };

-export const derivation = (_: NixValue): NixAttrs => {
-  throw new Error("unreachable: placeholder derivation implementation called")
+export const derivationStub = (_: NixValue): NixAttrs => {
+  throw new Error("unreachable: stub derivation implementation called");
 };
--- a/nix-js/runtime-ts/src/builtins/flake.ts
+++ b/nix-js/runtime-ts/src/builtins/flake.ts
@@ -0,0 +1,17 @@
+import type { NixValue } from "../types";
+
+export const getFlake = (_attrs: NixValue): never => {
+  throw new Error("Not implemented: getFlake");
+};
+
+export const parseFlakeName = (_s: NixValue): never => {
+  throw new Error("Not implemented: parseFlakeName");
+};
+
+export const parseFlakeRef = (_s: NixValue): never => {
+  throw new Error("Not implemented: parseFlakeRef");
+};
+
+export const flakeRefToString = (_attrs: NixValue): never => {
+  throw new Error("Not implemented: flakeRefToString");
+};
--- a/nix-js/runtime-ts/src/builtins/functional.ts
+++ b/nix-js/runtime-ts/src/builtins/functional.ts
@@ -1,11 +1,7 @@
-/**
- * Functional programming builtin functions
- */
-
-import { CatchableError, type NixValue } from "../types";
-import { force } from "../thunk";
-import { coerceToString, StringCoercionMode } from "./conversion";
 import { printValue } from "../print";
+import { force } from "../thunk";
+import { CatchableError, type NixValue } from "../types";
+import { coerceToString, StringCoercionMode } from "./conversion";
 import { isAttrs } from "./type-check";

 export const seq =
@@ -31,7 +27,7 @@ export const deepSeq =
          recurse(val);
        }
      } else if (isAttrs(forced)) {
-        for (const [_, val] of Object.entries(forced)) {
+        for (const [_, val] of forced.entries()) {
          recurse(val);
        }
      }
@@ -45,7 +41,7 @@ export const abort = (s: NixValue): never => {
 };

 export const throwFunc = (s: NixValue): never => {
-  throw new CatchableError(coerceToString(s, StringCoercionMode.Base));
+  throw new CatchableError(coerceToString(s, StringCoercionMode.Base, false, new Set()));
 };

 export const trace =
--- a/nix-js/runtime-ts/src/builtins/hash.ts
+++ b/nix-js/runtime-ts/src/builtins/hash.ts
@@ -0,0 +1,34 @@
+import { select } from "../helpers";
+import { forceAttrs, forceStringNoCtx, forceStringValue } from "../type-assert";
+import type { NixValue } from "../types";
+import { realisePath } from "./io";
+
+export const hashFile =
+  (type: NixValue) =>
+  (p: NixValue): string => {
+    const algo = forceStringNoCtx(type);
+    const pathStr = realisePath(p);
+    return Deno.core.ops.op_hash_file(algo, pathStr);
+  };
+
+export const hashString =
+  (type: NixValue) =>
+  (s: NixValue): string => {
+    const algo = forceStringNoCtx(type);
+    const data = forceStringValue(s);
+    return Deno.core.ops.op_hash_string(algo, data);
+  };
+
+export const convertHash = (args: NixValue): string => {
+  const attrs = forceAttrs(args);
+  const hash = forceStringNoCtx(select(attrs, ["hash"]));
+
+  let hashAlgo: string | null = null;
+  if (attrs.has("hashAlgo")) {
+    hashAlgo = forceStringNoCtx(select(attrs, ["hashAlgo"]));
+  }
+
+  const toHashFormat = forceStringNoCtx(select(attrs, ["toHashFormat"]));
+
+  return Deno.core.ops.op_convert_hash(hash, hashAlgo, toHashFormat);
+};
--- a/nix-js/runtime-ts/src/builtins/index.ts
+++ b/nix-js/runtime-ts/src/builtins/index.ts
@@ -1,85 +1,54 @@
-/**
- * Main builtins export
- * Combines all builtin function categories into the global `builtins` object
- */
-
-// Import all builtin categories
+import { createThunk, force } from "../thunk";
+import type { NixAttrs, NixFunction, NixValue } from "../types";
 import * as arithmetic from "./arithmetic";
-import * as math from "./math";
-import * as typeCheck from "./type-check";
-import * as list from "./list";
 import * as attrs from "./attrs";
-import * as string from "./string";
-import * as pathOps from "./path";
-import * as functional from "./functional";
-import * as io from "./io";
 import * as conversion from "./conversion";
-import * as misc from "./misc";
 import * as derivation from "./derivation";
+import * as flake from "./flake";
+import * as functional from "./functional";
+import * as hash from "./hash";
+import * as io from "./io";
+import * as list from "./list";
+import * as math from "./math";
+import * as misc from "./misc";
+import * as pathOps from "./path";
+import * as string from "./string";
+import * as typeCheck from "./type-check";

-import type { NixValue } from "../types";
-import { createThunk, force, isThunk } from "../thunk";
-import { getTos } from "../helpers";
-
-/**
- * Symbol used to mark functions as primops (primitive operations)
- * This is similar to IS_THUNK but for builtin functions
- */
 export const PRIMOP_METADATA = Symbol("primop_metadata");

-/**
- * Metadata interface for primop functions
- */
 export interface PrimopMetadata {
-  /** The name of the primop (e.g., "add", "map") */
  name: string;
-  /** Total arity of the function (number of arguments it expects) */
  arity: number;
-  /** Number of arguments already applied (for partial applications) */
  applied: number;
 }

-/**
- * Mark a function as a primop with metadata
- * For curried functions, this recursively marks each layer
- *
- * @param func - The function to mark
- * @param name - Name of the primop
- * @param arity - Total number of arguments expected
- * @param applied - Number of arguments already applied (default: 0)
- * @returns The marked function
- */
 export const mkPrimop = (
-  func: (...args: NixValue[]) => NixValue,
+  func: NixFunction,
  name: string,
  arity: number,
  applied: number = 0,
-): Function => {
-  // Mark this function as a primop
-  (func as any)[PRIMOP_METADATA] = {
+): ((...args: NixValue[]) => NixValue) => {
+  func[PRIMOP_METADATA] = {
    name,
    arity,
    applied,
  } satisfies PrimopMetadata;

-  // If this is a curried function and not fully applied,
-  // wrap it to mark the next layer too
  if (applied < arity - 1) {
-    const wrappedFunc = ((...args: NixValue[]) => {
-      const result = func(...args);
-      // If result is a function, mark it as the next layer
+    const wrappedFunc: NixFunction = ((arg: NixValue) => {
+      const result = func(arg);
      if (typeof result === "function") {
-        return mkPrimop(result, name, arity, applied + args.length);
+        return mkPrimop(result, name, arity, applied + 1);
      }
      return result;
-    }) as any;
+    });

-    // Copy the primop metadata to the wrapper
    wrappedFunc[PRIMOP_METADATA] = {
      name,
      arity,
      applied,
-    } satisfies PrimopMetadata;
+    };

    return wrappedFunc;
  }
@@ -87,12 +56,9 @@ export const mkPrimop = (
  return func;
 };

-/**
- * Type guard to check if a value is a primop
- * @param value - Value to check
- * @returns true if value is marked as a primop
- */
-export const is_primop = (value: unknown): value is Function & { [PRIMOP_METADATA]: PrimopMetadata } => {
+export const isPrimop = (
+  value: NixValue,
+): value is NixFunction & { [PRIMOP_METADATA]: PrimopMetadata } => {
  return (
    typeof value === "function" &&
    PRIMOP_METADATA in value &&
@@ -101,29 +67,15 @@ export const is_primop = (value: unknown): value is Function & { [PRIMOP_METADAT
  );
 };

-/**
- * Get primop metadata from a function
- * @param func - Function to get metadata from
- * @returns Metadata if function is a primop, undefined otherwise
- */
-export const get_primop_metadata = (func: unknown): PrimopMetadata | undefined => {
-  if (is_primop(func)) {
+export const getPrimopMetadata = (func: NixValue): PrimopMetadata | undefined => {
+  if (isPrimop(func)) {
    return func[PRIMOP_METADATA];
  }
  return undefined;
 };

-/**
- * The global builtins object
- * Contains 80+ Nix builtin functions plus metadata
- *
- * All functions are curried for Nix semantics:
- * - Single argument functions: (a) => result
- * - Multi-argument functions: (a) => (b) => result
- *
- * All primop functions are marked with PRIMOP_METADATA symbol for runtime introspection
- */
-export const builtins: any = {
+export const builtins: NixAttrs = new Map<string, NixValue>(
+  Object.entries({
    add: mkPrimop(arithmetic.add, "add", 2),
    sub: mkPrimop(arithmetic.sub, "sub", 2),
    mul: mkPrimop(arithmetic.mul, "mul", 2),
@@ -193,7 +145,7 @@ export const builtins: any = {
    warn: mkPrimop(functional.warn, "warn", 2),
    break: mkPrimop(functional.breakFunc, "break", 1),

-  derivation: undefined as any,
+    derivation: mkPrimop(derivation.derivationStub, "derivation", 1),
    derivationStrict: mkPrimop(derivation.derivationStrict, "derivationStrict", 1),

    import: mkPrimop(io.importFunc, "import", 1),
@@ -221,13 +173,19 @@ export const builtins: any = {
    toXML: mkPrimop(conversion.toXML, "toXML", 1),
    toString: mkPrimop(conversion.toStringFunc, "toString", 1),

+    hashFile: mkPrimop(hash.hashFile, "hashFile", 2),
+    hashString: mkPrimop(hash.hashString, "hashString", 2),
+    convertHash: mkPrimop(hash.convertHash, "convertHash", 2),
+
+    flakeRefToString: mkPrimop(flake.flakeRefToString, "flakeRefToString", 1),
+    getFlake: mkPrimop(flake.getFlake, "getFlake", 1),
+    parseFlakeName: mkPrimop(flake.parseFlakeName, "parseFlakeName", 1),
+    parseFlakeRef: mkPrimop(flake.parseFlakeRef, "parseFlakeRef", 1),
+
    addErrorContext: mkPrimop(misc.addErrorContext, "addErrorContext", 1),
    appendContext: mkPrimop(misc.appendContext, "appendContext", 1),
    getContext: mkPrimop(misc.getContext, "getContext", 1),
    hasContext: mkPrimop(misc.hasContext, "hasContext", 1),
-  hashFile: mkPrimop(misc.hashFile, "hashFile", 2),
-  hashString: mkPrimop(misc.hashString, "hashString", 2),
-  convertHash: mkPrimop(misc.convertHash, "convertHash", 2),
    unsafeDiscardOutputDependency: mkPrimop(
      misc.unsafeDiscardOutputDependency,
      "unsafeDiscardOutputDependency",
@@ -236,14 +194,10 @@ export const builtins: any = {
    unsafeDiscardStringContext: mkPrimop(misc.unsafeDiscardStringContext, "unsafeDiscardStringContext", 1),
    addDrvOutputDependencies: mkPrimop(misc.addDrvOutputDependencies, "addDrvOutputDependencies", 2),
    compareVersions: mkPrimop(misc.compareVersions, "compareVersions", 2),
-  flakeRefToString: mkPrimop(misc.flakeRefToString, "flakeRefToString", 1),
    functionArgs: mkPrimop(misc.functionArgs, "functionArgs", 1),
    genericClosure: mkPrimop(misc.genericClosure, "genericClosure", 1),
-  getFlake: mkPrimop(misc.getFlake, "getFlake", 1),
    outputOf: mkPrimop(misc.outputOf, "outputOf", 2),
    parseDrvName: mkPrimop(misc.parseDrvName, "parseDrvName", 1),
-  parseFlakeName: mkPrimop(misc.parseFlakeName, "parseFlakeName", 1),
-  parseFlakeRef: mkPrimop(misc.parseFlakeRef, "parseFlakeRef", 1),
    placeholder: mkPrimop(misc.placeholder, "placeholder", 1),
    replaceStrings: mkPrimop(misc.replaceStrings, "replaceStrings", 3),
    splitVersion: mkPrimop(misc.splitVersion, "splitVersion", 1),
@@ -263,10 +217,8 @@ export const builtins: any = {
    langVersion: 6,
    nixPath: [],
    nixVersion: "2.31.2",
-  storeDir: "INVALID_PATH",
-
-  __traceCaller: (e: NixValue) => {
-    console.log(`traceCaller: ${getTos()}`);
-    return e;
-  },
-};
+    storeDir: createThunk(() => {
+      throw new Error("stub storeDir evaluated");
+    }),
+  }),
+);
--- a/nix-js/runtime-ts/src/builtins/io.ts
+++ b/nix-js/runtime-ts/src/builtins/io.ts
@@ -1,8 +1,8 @@
-/**
- * I/O and filesystem builtin functions
- * Implemented via Rust ops exposed through deno_core
- */
-
+import { select } from "../helpers";
+import { getPathValue } from "../path";
+import type { NixStringContext, StringWithContext } from "../string-context";
+import { addOpaqueContext, decodeContextElem, mkStringWithContext } from "../string-context";
+import { force } from "../thunk";
 import {
  forceAttrs,
  forceBool,
@@ -11,42 +11,47 @@ import {
  forceStringNoCtx,
  forceStringValue,
 } from "../type-assert";
-import type { NixValue, NixAttrs, NixPath, NixString } from "../types";
-import { isNixPath, IS_PATH, CatchableError } from "../types";
-import { force } from "../thunk";
+import type { NixAttrs, NixString, NixValue } from "../types";
+import { CatchableError, isNixPath, NixPath } from "../types";
 import { coerceToPath, coerceToString, StringCoercionMode } from "./conversion";
-import { getPathValue } from "../path";
-import type { NixStringContext, StringWithContext } from "../string-context";
-import { mkStringWithContext, addOpaqueContext } from "../string-context";
-import { isAttrs, isPath } from "./type-check";
 import { baseNameOf } from "./path";
+import { isAttrs, isPath, isString } from "./type-check";
+import { execBytecode, execBytecodeScoped } from "../vm";

 const importCache = new Map<string, NixValue>();

-export const importFunc = (path: NixValue): NixValue => {
-  const context: NixStringContext = new Set();
-  const pathStr = coerceToPath(path, context);
-
-  // FIXME: Context collected but not yet propagated to build system
-  // This means derivation dependencies from imported paths are not
-  // currently tracked. This will cause issues when:
-  // 1. Importing from derivation outputs: import "${drv}/file.nix"
-  // 2. Building packages that depend on imported configurations
-  if (context.size > 0) {
-    console.warn(
-      `[WARN] import: Path has string context which is not yet fully tracked.
-Dependency tracking for imported derivations may be incomplete.`,
+const realiseContext = (context: NixStringContext): void => {
+  for (const encoded of context) {
+    const elem = decodeContextElem(encoded);
+    if (elem.type === "built") {
+      throw new Error(
+        `cannot build derivation '${elem.drvPath}' during evaluation because import-from-derivation is not supported`,
      );
    }
+  }
+};
+
+export const realisePath = (value: NixValue): string => {
+  const context: NixStringContext = new Set();
+  const pathStr = coerceToPath(value, context);
+
+  if (context.size > 0) {
+    realiseContext(context);
+  }
+
+  return pathStr;
+};
+
+export const importFunc = (path: NixValue): NixValue => {
+  const pathStr = realisePath(path);

  const cached = importCache.get(pathStr);
  if (cached !== undefined) {
    return cached;
  }

-  // Call Rust op - returns JS code string
-  const code = Deno.core.ops.op_import(pathStr);
-  const result = Function(`return (${code})`)();
+  const [code, currentDir] = Deno.core.ops.op_import(pathStr);
+  const result = execBytecode(code, currentDir);

  importCache.set(pathStr, result);
  return result;
@@ -56,22 +61,12 @@ export const scopedImport =
  (scope: NixValue) =>
  (path: NixValue): NixValue => {
    const scopeAttrs = forceAttrs(scope);
-    const scopeKeys = Object.keys(scopeAttrs);
+    const scopeKeys = Array.from(scopeAttrs.keys());

-    const context: NixStringContext = new Set();
-    const pathStr = coerceToPath(path, context);
+    const pathStr = realisePath(path);

-    if (context.size > 0) {
-      console.warn(
-        `[WARN] scopedImport: Path has string context which is not yet fully tracked.
-Dependency tracking for imported derivations may be incomplete.`,
-      );
-    }
-
-    const code = Deno.core.ops.op_scoped_import(pathStr, scopeKeys);
-
-    const scopedFunc = Function(`return (${code})`)();
-    return scopedFunc(scopeAttrs);
+    const [code, currentDir] = Deno.core.ops.op_scoped_import(pathStr, scopeKeys);
+    return execBytecodeScoped(code, currentDir, scopeAttrs);
  };

 export const storePath = (pathArg: NixValue): StringWithContext => {
@@ -84,29 +79,29 @@ export const storePath = (pathArg: NixValue): StringWithContext => {
  return mkStringWithContext(validatedPath, context);
 };

-export const fetchClosure = (args: NixValue): never => {
+export const fetchClosure = (_args: NixValue): never => {
  throw new Error("Not implemented: fetchClosure");
 };

 export interface FetchUrlResult {
-  store_path: string;
+  storePath: string;
  hash: string;
 }

 export interface FetchTarballResult {
-  store_path: string;
-  nar_hash: string;
+  storePath: string;
+  narHash: string;
 }

 export interface FetchGitResult {
-  out_path: string;
+  outPath: string;
  rev: string;
-  short_rev: string;
-  rev_count: number;
-  last_modified: number;
-  last_modified_date: string;
+  shortRev: string;
+  revCount: number;
+  lastModified: number;
+  lastModifiedDate: string;
  submodules: boolean;
-  nar_hash: string | null;
+  narHash: string | null;
 }

 const normalizeUrlInput = (
@@ -117,26 +112,24 @@ const normalizeUrlInput = (
    return { url: forced };
  }
  const attrs = forceAttrs(args);
-  const url = forceStringValue(attrs.url);
-  const hash =
-    "sha256" in attrs
-      ? forceStringValue(attrs.sha256)
-      : "hash" in attrs
-        ? forceStringValue(attrs.hash)
+  const url = forceStringValue(select(attrs, ["url"]));
+  const hash = attrs.has("sha256")
+    ? forceStringValue(attrs.get("sha256") as NixValue)
+    : attrs.has("hash")
+      ? forceStringValue(attrs.get("hash") as NixValue)
      : undefined;
-  const name = "name" in attrs ? forceStringValue(attrs.name) : undefined;
-  const executable = "executable" in attrs ? forceBool(attrs.executable) : false;
+  const name = attrs.has("name") ? forceStringValue(attrs.get("name") as NixValue) : undefined;
+  const executable = attrs.has("executable") ? forceBool(attrs.get("executable") as NixValue) : false;
  return { url, hash, name, executable };
 };

 const normalizeTarballInput = (args: NixValue): { url: string; sha256?: string; name?: string } => {
  const forced = force(args);
  if (isAttrs(forced)) {
-    const url = resolvePseudoUrl(forceStringNoCtx(forced.url));
-    const sha256 = "sha256" in forced ? forceStringNoCtx(forced.sha256) : undefined;
-    const nameRaw = "name" in forced ? forceStringNoCtx(forced.name) : undefined;
-    // FIXME: extract baseNameOfRaw
-    const name = nameRaw === "" ? baseNameOf(nameRaw) as string : nameRaw;
+    const url = resolvePseudoUrl(forceStringNoCtx(select(forced, ["url"])));
+    const sha256 = forced.has("sha256") ? forceStringNoCtx(forced.get("sha256") as NixValue) : undefined;
+    const nameRaw = forced.has("name") ? forceStringNoCtx(forced.get("name") as NixValue) : undefined;
+    const name = nameRaw === "" ? (baseNameOf(nameRaw) as string) : nameRaw;
    return { url, sha256, name };
  } else {
    return { url: forceStringNoCtx(forced) };
@@ -145,11 +138,11 @@ const normalizeTarballInput = (args: NixValue): { url: string; sha256?: string;

 const resolvePseudoUrl = (url: string) => {
  if (url.startsWith("channel:")) {
-    return `https://channels.nixos.org/${url.substring(8)}/nixexprs.tar.xz`
+    return `https://channels.nixos.org/${url.substring(8)}/nixexprs.tar.xz`;
  } else {
-    return url
-  }
+    return url;
  }
+};

 export const fetchurl = (args: NixValue): NixString => {
  const { url, hash, name, executable } = normalizeUrlInput(args);
@@ -160,44 +153,45 @@ export const fetchurl = (args: NixValue): NixString => {
    executable ?? false,
  );
  const context: NixStringContext = new Set();
-  addOpaqueContext(context, result.store_path);
-  return mkStringWithContext(result.store_path, context);
+  addOpaqueContext(context, result.storePath);
+  return mkStringWithContext(result.storePath, context);
 };

 export const fetchTarball = (args: NixValue): NixString => {
  const { url, name, sha256 } = normalizeTarballInput(args);
  const result: FetchTarballResult = Deno.core.ops.op_fetch_tarball(url, name ?? null, sha256 ?? null);
  const context: NixStringContext = new Set();
-  addOpaqueContext(context, result.store_path);
-  return mkStringWithContext(result.store_path, context);
+  addOpaqueContext(context, result.storePath);
+  return mkStringWithContext(result.storePath, context);
 };

 export const fetchGit = (args: NixValue): NixAttrs => {
  const forced = force(args);
-  if (typeof forced === "string" || isPath(forced)) {
-    const path = coerceToPath(forced);
-    const result: FetchGitResult = Deno.core.ops.op_fetch_git(path, null, null, false, false, false, null);
+  const disposedContext: NixStringContext = new Set();
+  if (isString(forced) || isPath(forced)) {
+    const url = coerceToString(forced, StringCoercionMode.Base, false, disposedContext);
+    const result = Deno.core.ops.op_fetch_git(url, null, null, false, false, false, null);
    const outContext: NixStringContext = new Set();
-    addOpaqueContext(outContext, result.out_path);
-    return {
-      outPath: mkStringWithContext(result.out_path, outContext),
-      rev: result.rev,
-      shortRev: result.short_rev,
-      revCount: BigInt(result.rev_count),
-      lastModified: BigInt(result.last_modified),
-      lastModifiedDate: result.last_modified_date,
-      submodules: result.submodules,
-      narHash: result.nar_hash,
-    };
+    addOpaqueContext(outContext, result.outPath);
+    return new Map<string, NixValue>([
+      ["outPath", mkStringWithContext(result.outPath, outContext)],
+      ["rev", result.rev],
+      ["shortRev", result.shortRev],
+      ["revCount", BigInt(result.revCount)],
+      ["lastModified", BigInt(result.lastModified)],
+      ["lastModifiedDate", result.lastModifiedDate],
+      ["submodules", result.submodules],
+      ["narHash", result.narHash],
+    ]);
  }
  const attrs = forceAttrs(args);
-  const url = forceStringValue(attrs.url);
-  const gitRef = "ref" in attrs ? forceStringValue(attrs.ref) : null;
-  const rev = "rev" in attrs ? forceStringValue(attrs.rev) : null;
-  const shallow = "shallow" in attrs ? forceBool(attrs.shallow) : false;
-  const submodules = "submodules" in attrs ? forceBool(attrs.submodules) : false;
-  const allRefs = "allRefs" in attrs ? forceBool(attrs.allRefs) : false;
-  const name = "name" in attrs ? forceStringValue(attrs.name) : null;
+  const url = forceStringValue(select(attrs, ["url"]));
+  const gitRef = attrs.has("ref") ? forceStringValue(attrs.get("ref") as NixValue) : null;
+  const rev = attrs.has("rev") ? forceStringValue(attrs.get("rev") as NixValue) : null;
+  const shallow = attrs.has("shallow") ? forceBool(attrs.get("shallow") as NixValue) : false;
+  const submodules = attrs.has("submodules") ? forceBool(attrs.get("submodules") as NixValue) : false;
+  const allRefs = attrs.has("allRefs") ? forceBool(attrs.get("allRefs") as NixValue) : false;
+  const name = attrs.has("name") ? forceStringValue(attrs.get("name") as NixValue) : null;

  const result: FetchGitResult = Deno.core.ops.op_fetch_git(
    url,
@@ -210,26 +204,26 @@ export const fetchGit = (args: NixValue): NixAttrs => {
  );

  const outContext: NixStringContext = new Set();
-  addOpaqueContext(outContext, result.out_path);
-  return {
-    outPath: mkStringWithContext(result.out_path, outContext),
-    rev: result.rev,
-    shortRev: result.short_rev,
-    revCount: BigInt(result.rev_count),
-    lastModified: BigInt(result.last_modified),
-    lastModifiedDate: result.last_modified_date,
-    submodules: result.submodules,
-    narHash: result.nar_hash,
-  };
+  addOpaqueContext(outContext, result.outPath);
+  return new Map<string, NixValue>([
+    ["outPath", mkStringWithContext(result.outPath, outContext)],
+    ["rev", result.rev],
+    ["shortRev", result.shortRev],
+    ["revCount", BigInt(result.revCount)],
+    ["lastModified", BigInt(result.lastModified)],
+    ["lastModifiedDate", result.lastModifiedDate],
+    ["submodules", result.submodules],
+    ["narHash", result.narHash],
+  ]);
 };

 export const fetchMercurial = (_args: NixValue): NixAttrs => {
-  throw new Error("Not implemented: fetchMercurial")
+  throw new Error("Not implemented: fetchMercurial");
 };

 export const fetchTree = (args: NixValue): NixAttrs => {
  const attrs = forceAttrs(args);
-  const type = "type" in attrs ? forceStringValue(attrs.type) : "auto";
+  const type = attrs.has("type") ? forceStringValue(attrs.get("type") as NixValue) : "auto";

  switch (type) {
    case "git":
@@ -238,29 +232,31 @@ export const fetchTree = (args: NixValue): NixAttrs => {
    case "mercurial":
      return fetchMercurial(args);
    case "tarball":
-      return { outPath: fetchTarball(args) };
+      return new Map<string, NixValue>([["outPath", fetchTarball(args)]]);
    case "file":
-      return { outPath: fetchurl(args) };
+      return new Map<string, NixValue>([["outPath", fetchurl(args)]]);
    case "path": {
-      const path = forceStringValue(attrs.path);
-      return { outPath: path };
+      const path = forceStringValue(select(attrs, ["path"]));
+      return new Map<string, NixValue>([["outPath", path]]);
    }
    case "github":
    case "gitlab":
    case "sourcehut":
      return fetchGitForge(type, attrs);
-    case "auto":
    default:
      return autoDetectAndFetch(attrs);
  }
 };

 const fetchGitForge = (forge: string, attrs: NixAttrs): NixAttrs => {
-  const owner = forceStringValue(attrs.owner);
-  const repo = forceStringValue(attrs.repo);
-  const rev =
-    "rev" in attrs ? forceStringValue(attrs.rev) : "ref" in attrs ? forceStringValue(attrs.ref) : "HEAD";
-  const host = "host" in attrs ? forceStringValue(attrs.host) : undefined;
+  const owner = forceStringValue(select(forge, ["owner"]));
+  const repo = forceStringValue(select(forge, ["repo"]));
+  const rev = attrs.has("rev")
+    ? forceStringValue(attrs.get("rev") as NixValue)
+    : attrs.has("ref")
+      ? forceStringValue(attrs.get("ref") as NixValue)
+      : "HEAD";
+  const host = attrs.has("host") ? forceStringValue(attrs.get("host") as NixValue) : undefined;

  let tarballUrl: string;
  switch (forge) {
@@ -283,17 +279,17 @@ const fetchGitForge = (forge: string, attrs: NixAttrs): NixAttrs => {
      throw new Error(`Unknown forge type: ${forge}`);
  }

-  const outPath = fetchTarball({ url: tarballUrl, ...attrs });
+  const outPath = fetchTarball(new Map<string, NixValue>([["url", tarballUrl], ...attrs]));

-  return {
-    outPath,
-    rev,
-    shortRev: rev.substring(0, 7),
-  };
+  return new Map<string, NixValue>([
+    ["outPath", outPath],
+    ["rev", rev],
+    ["shortRev", rev.substring(0, 7)],
+  ]);
 };

 const autoDetectAndFetch = (attrs: NixAttrs): NixAttrs => {
-  const url = forceStringValue(attrs.url);
+  const url = forceStringValue(select(attrs, ["url"]));
  if (url.endsWith(".git") || url.includes("github.com") || url.includes("gitlab.com")) {
    return fetchGit(attrs);
  }
@@ -303,34 +299,33 @@ const autoDetectAndFetch = (attrs: NixAttrs): NixAttrs => {
    url.endsWith(".tar.bz2") ||
    url.endsWith(".tgz")
  ) {
-    return { outPath: fetchTarball(attrs) };
+    return new Map<string, NixValue>([["outPath", fetchTarball(attrs)]]);
  }
-  return { outPath: fetchurl(attrs) };
+  return new Map<string, NixValue>([["outPath", fetchurl(attrs)]]);
 };

 export const readDir = (path: NixValue): NixAttrs => {
-  const pathStr = coerceToPath(path);
-  const entries: Record<string, string> = Deno.core.ops.op_read_dir(pathStr);
-  const result: NixAttrs = {};
-  for (const [name, type] of Object.entries(entries)) {
-    result[name] = type;
-  }
-  return result;
+  const pathStr = realisePath(path);
+  return Deno.core.ops.op_read_dir(pathStr);
 };

 export const readFile = (path: NixValue): string => {
-  const pathStr = coerceToPath(path);
+  const pathStr = realisePath(path);
  return Deno.core.ops.op_read_file(pathStr);
 };

 export const readFileType = (path: NixValue): string => {
-  const pathStr = coerceToPath(path);
+  const pathStr = realisePath(path);
  return Deno.core.ops.op_read_file_type(pathStr);
 };

 export const pathExists = (path: NixValue): boolean => {
-  const pathStr = coerceToPath(path);
+  try {
+    const pathStr = realisePath(path);
    return Deno.core.ops.op_path_exists(pathStr);
+  } catch {
+    return false;
+  }
 };

 /**
@@ -349,11 +344,11 @@ export const pathExists = (path: NixValue): boolean => {
 export const path = (args: NixValue): NixString => {
  const attrs = forceAttrs(args);

-  if (!("path" in attrs)) {
+  if (!attrs.has("path")) {
    throw new TypeError("builtins.path: 'path' attribute is required");
  }

-  const pathValue = force(attrs.path);
+  const pathValue = force(attrs.get("path") as NixValue);
  let pathStr: string;

  if (isNixPath(pathValue)) {
@@ -362,20 +357,20 @@ export const path = (args: NixValue): NixString => {
    pathStr = forceStringValue(pathValue);
  }

-  const name = "name" in attrs ? forceStringValue(attrs.name) : null;
-  const recursive = "recursive" in attrs ? forceBool(attrs.recursive) : true;
-  const sha256 = "sha256" in attrs ? forceStringValue(attrs.sha256) : null;
+  const name = attrs.has("name") ? forceStringValue(attrs.get("name") as NixValue) : null;
+  const recursive = attrs.has("recursive") ? forceBool(attrs.get("recursive") as NixValue) : true;
+  const sha256 = attrs.has("sha256") ? forceStringValue(attrs.get("sha256") as NixValue) : null;

  let storePath: string;

-  if ("filter" in attrs) {
-    const filterFn = forceFunction(attrs.filter);
+  if (attrs.has("filter")) {
+    const filterFn = forceFunction(attrs.get("filter") as NixValue);

    const entries: [string, string][] = Deno.core.ops.op_walk_dir(pathStr);

    const includePaths: string[] = [];
    for (const [relPath, fileType] of entries) {
-      const fullPath = pathStr + "/" + relPath;
+      const fullPath = `${pathStr}/${relPath}`;
      const innerFn = forceFunction(filterFn(fullPath));
      const shouldInclude = force(innerFn(fileType));
      if (shouldInclude === true) {
@@ -383,13 +378,7 @@ export const path = (args: NixValue): NixString => {
      }
    }

-    storePath = Deno.core.ops.op_add_filtered_path(
-      pathStr,
-      name,
-      recursive,
-      sha256,
-      includePaths,
-    );
+    storePath = Deno.core.ops.op_add_filtered_path(pathStr, name, recursive, sha256, includePaths);
  } else {
    storePath = Deno.core.ops.op_add_path(pathStr, name, recursive, sha256);
  }
@@ -421,11 +410,9 @@ export const toFile =
    return mkStringWithContext(storePath, new Set([storePath]));
  };

-export const toPath = (name: NixValue, s: NixValue): never => {
-  throw new Error("Not implemented: toPath");
-};
-
-export const filterSource = (args: NixValue): never => {
+export const filterSource =
+  (_filter: NixValue) =>
+  (_path: NixValue): never => {
    throw new Error("Not implemented: filterSource");
  };

@@ -454,9 +441,9 @@ export const findFile =
    for (const item of forcedSearchPath) {
      const attrs = forceAttrs(item);

-      const prefix = "prefix" in attrs ? forceStringNoCtx(attrs.prefix) : "";
+      const prefix = attrs.has("prefix") ? forceStringNoCtx(attrs.get("prefix") as NixValue) : "";

-      if (!("path" in attrs)) {
+      if (!attrs.has("path")) {
        throw new Error("findFile: search path element is missing 'path' attribute");
      }

@@ -466,7 +453,12 @@ export const findFile =
      }

      const context: NixStringContext = new Set();
-      const pathVal = coerceToString(attrs.path, StringCoercionMode.Interpolation, false, context);
+      const pathVal = coerceToString(
+        attrs.get("path") as NixValue,
+        StringCoercionMode.Interpolation,
+        false,
+        context,
+      );

      if (context.size > 0) {
        throw new Error("findFile: path with string context is not yet supported");
@@ -477,13 +469,13 @@ export const findFile =
        suffix.length > 0 ? Deno.core.ops.op_resolve_path(suffix, resolvedPath) : resolvedPath;

      if (Deno.core.ops.op_path_exists(candidatePath)) {
-        return { [IS_PATH]: true, value: candidatePath };
+        return new NixPath(candidatePath);
      }
    }

    if (lookupPathStr.startsWith("nix/")) {
      // FIXME: special path type
-      return { [IS_PATH]: true, value: `<${lookupPathStr}>` };
+      return new NixPath(`<${lookupPathStr}>`);
    }

    throw new CatchableError(`file '${lookupPathStr}' was not found in the Nix search path`);
--- a/nix-js/runtime-ts/src/builtins/list.ts
+++ b/nix-js/runtime-ts/src/builtins/list.ts
@@ -1,12 +1,7 @@
-/**
- * List operation builtin functions
- * All functions are properly curried
- */
-
-import type { NixValue, NixList, NixAttrs } from "../types";
-import { force } from "../thunk";
-import { forceList, forceFunction, forceInt, forceBool } from "../type-assert";
 import { op } from "../operators";
+import { force } from "../thunk";
+import { forceBool, forceFunction, forceInt, forceList } from "../type-assert";
+import type { NixAttrs, NixList, NixValue } from "../types";

 export const map =
  (f: NixValue) =>
@@ -74,23 +69,23 @@ export const concatMap =
  };

 export const foldlPrime =
-  (op_fn: NixValue) =>
+  (opFn: NixValue) =>
  (nul: NixValue) =>
  (list: NixValue): NixValue => {
-    const forced_op = forceFunction(op_fn);
+    const forcedOp = forceFunction(opFn);
    return forceList(list).reduce((acc: NixValue, cur: NixValue) => {
-      return forceFunction(forced_op(acc))(cur);
+      return forceFunction(forcedOp(acc))(cur);
    }, nul);
  };

 export const sort =
  (cmp: NixValue) =>
  (list: NixValue): NixList => {
-    const forced_list = [...forceList(list)];
-    const forced_cmp = forceFunction(cmp);
-    return forced_list.sort((a, b) => {
-      if (force(forceFunction(forced_cmp(a))(b))) return -1;
-      if (force(forceFunction(forced_cmp(b))(a))) return 1;
+    const forcedList = [...forceList(list)];
+    const forcedCmp = forceFunction(cmp);
+    return forcedList.sort((a, b) => {
+      if (force(forceFunction(forcedCmp(a))(b))) return -1;
+      if (force(forceFunction(forcedCmp(b))(a))) return 1;
      return 0;
    });
  };
@@ -98,20 +93,21 @@ export const sort =
 export const partition =
  (pred: NixValue) =>
  (list: NixValue): NixAttrs => {
-    const forced_list = forceList(list);
-    const forced_pred = forceFunction(pred);
-    const attrs = {
-      right: [] as NixList,
-      wrong: [] as NixList,
-    };
-    for (const elem of forced_list) {
-      if (force(forced_pred(elem))) {
-        attrs.right.push(elem);
+    const forcedList = forceList(list);
+    const forcedPred = forceFunction(pred);
+    const right: NixList = [];
+    const wrong: NixList = [];
+    for (const elem of forcedList) {
+      if (force(forcedPred(elem))) {
+        right.push(elem);
      } else {
-        attrs.wrong.push(elem);
+        wrong.push(elem);
      }
    }
-    return attrs;
+    return new Map<string, NixValue>([
+      ["right", right],
+      ["wrong", wrong],
+    ]);
  };

 export const genList =
--- a/nix-js/runtime-ts/src/builtins/math.ts
+++ b/nix-js/runtime-ts/src/builtins/math.ts
@@ -1,9 +1,5 @@
-/**
- * Math builtin functions
- */
-
-import type { NixValue } from "../types";
 import { forceNumeric } from "../type-assert";
+import type { NixValue } from "../types";

 export const ceil = (x: NixValue): bigint => {
  const val = forceNumeric(x);
--- a/nix-js/runtime-ts/src/builtins/misc.ts
+++ b/nix-js/runtime-ts/src/builtins/misc.ts
@@ -1,31 +1,28 @@
-/**
- * Miscellaneous builtin functions
- */
-
-import { force } from "../thunk";
-import { CatchableError, ATTR_POSITIONS } from "../types";
-import type { NixAttrs, NixBool, NixStrictValue, NixValue } from "../types";
+import { OrderedSet } from "js-sdsl";
+import { select } from "../helpers";
+import { compareValues } from "../operators";
+import {
+  getStringContext,
+  getStringValue,
+  mkStringWithContext,
+  type NixStringContext,
+} from "../string-context";
+import { force } from "../thunk";
 import {
-  forceList,
  forceAttrs,
  forceFunction,
-  forceStringValue,
+  forceList,
  forceString,
  forceStringNoCtx,
+  forceStringValue,
 } from "../type-assert";
+import type { NixAttrs, NixStrictValue, NixValue } from "../types";
+import { ATTR_POSITIONS, CatchableError } from "../types";
 import * as context from "./context";
-import { compareValues } from "../operators";
 import { isBool, isFloat, isInt, isList, isString, typeOf } from "./type-check";
-import { OrderedSet } from "js-sdsl";
-import {
-  type NixStringContext,
-  getStringValue,
-  getStringContext,
-  mkStringWithContext,
-} from "../string-context";

 export const addErrorContext =
-  (e1: NixValue) =>
+  (_e1: NixValue) =>
  (e2: NixValue): NixValue => {
    // FIXME:
    // console.log("[WARNING]: addErrorContext not implemented");
@@ -38,23 +35,6 @@ export const getContext = context.getContext;

 export const hasContext = context.hasContext;

-export const hashFile =
-  (type: NixValue) =>
-  (p: NixValue): never => {
-    const ty = forceStringNoCtx(type);
-    throw new Error("Not implemented: hashFile");
-  };
-
-export const hashString =
-  (type: NixValue) =>
-  (p: NixValue): never => {
-    throw new Error("Not implemented: hashString");
-  };
-
-export const convertHash = (args: NixValue): never => {
-  throw new Error("Not implemented: convertHash");
-};
-
 export const unsafeDiscardOutputDependency = context.unsafeDiscardOutputDependency;

 export const unsafeDiscardStringContext = context.unsafeDiscardStringContext;
@@ -77,9 +57,9 @@ export const compareVersions =
      i1 = c1.nextIndex;
      i2 = c2.nextIndex;

-      if (componentsLT(c1.component, c2.component)) {
+      if (componentsLt(c1.component, c2.component)) {
        return -1n;
-      } else if (componentsLT(c2.component, c1.component)) {
+      } else if (componentsLt(c2.component, c1.component)) {
        return 1n;
      }
    }
@@ -121,7 +101,7 @@ function nextComponent(s: string, startIdx: number): ComponentResult {
  return { component: s.substring(start, p), nextIndex: p };
 }

-function componentsLT(c1: string, c2: string): boolean {
+function componentsLt(c1: string, c2: string): boolean {
  const n1 = c1.match(/^[0-9]+$/) ? BigInt(c1) : null;
  const n2 = c2.match(/^[0-9]+$/) ? BigInt(c2) : null;

@@ -155,35 +135,23 @@ function componentsLT(c1: string, c2: string): boolean {
  return c1 < c2;
 }

-export const dirOf = (s: NixValue): never => {
-  throw new Error("Not implemented: dirOf");
-};
-
-export const flakeRefToString = (attrs: NixValue): never => {
-  throw new Error("Not implemented: flakeRefToString");
-};
-
 export const functionArgs = (f: NixValue): NixAttrs => {
  const func = forceFunction(f);
  if (func.args) {
-    const ret: NixAttrs = {};
-    for (const key of func.args!.required) {
-      ret[key] = false;
+    const ret: NixAttrs = new Map();
+    for (const key of func.args.required) {
+      ret.set(key, false);
    }
-    for (const key of func.args!.optional) {
-      ret[key] = true;
+    for (const key of func.args.optional) {
+      ret.set(key, true);
    }
-    const positions = func.args!.positions;
-    if (positions && Object.keys(positions).length > 0) {
-      Object.defineProperty(ret, ATTR_POSITIONS, {
-        value: positions,
-        enumerable: false,
-        writable: false,
-      });
+    const positions = func.args.positions;
+    if (positions) {
+      ret[ATTR_POSITIONS] = positions;
    }
    return ret;
  }
-  return {};
+  return new Map();
 };

 const checkComparable = (value: NixStrictValue): void => {
@@ -195,7 +163,8 @@ const checkComparable = (value: NixStrictValue): void => {

 export const genericClosure = (args: NixValue): NixValue => {
  const forcedArgs = forceAttrs(args);
-  const { startSet, operator } = forcedArgs;
+  const startSet = select(forcedArgs, ["startSet"]);
+  const operator = select(forcedArgs, ["operator"]);

  const initialList = forceList(startSet);
  const opFunction = forceFunction(operator);
@@ -206,7 +175,7 @@ export const genericClosure = (args: NixValue): NixValue => {

  for (const item of initialList) {
    const itemAttrs = forceAttrs(item);
-    const key = force(itemAttrs.key);
+    const key = force(select(itemAttrs, ["key"]));
    checkComparable(key);
    if (resultSet.find(key).equals(resultSet.end())) {
      resultSet.insert(key);
@@ -222,7 +191,7 @@ export const genericClosure = (args: NixValue): NixValue => {

    for (const newItem of newItems) {
      const newItemAttrs = forceAttrs(newItem);
-      const key = force(newItemAttrs.key);
+      const key = force(select(newItemAttrs, ["key"]));
      checkComparable(key);
      if (resultSet.find(key).equals(resultSet.end())) {
        resultSet.insert(key);
@@ -235,14 +204,10 @@ export const genericClosure = (args: NixValue): NixValue => {
  return resultList;
 };

-export const getFlake = (attrs: NixValue): never => {
-  throw new Error("Not implemented: getFlake");
-};
-
 export const outputOf =
-  (drv: NixValue) =>
-  (out: NixValue): never => {
-    throw new Error("Not implemented: outputOf");
+  (_drv: NixValue) =>
+  (_out: NixValue): never => {
+    throw new Error("Not implemented: outputOf (part of dynamic-derivation)");
  };

 export const parseDrvName = (s: NixValue): NixAttrs => {
@@ -256,18 +221,10 @@ export const parseDrvName = (s: NixValue): NixAttrs => {
      break;
    }
  }
-  return {
-    name,
-    version,
-  };
-};
-
-export const parseFlakeName = (s: NixValue): never => {
-  throw new Error("Not implemented: parseFlakeName");
-};
-
-export const parseFlakeRef = (s: NixValue): never => {
-  throw new Error("Not implemented: parseFlakeRef");
+  return new Map<string, NixValue>([
+    ["name", name],
+    ["version", version],
+  ]);
 };

 export const placeholder = (output: NixValue): NixValue => {
@@ -314,7 +271,7 @@ export const replaceStrings =
              resultContext.add(elem);
            }
          }
-          const replacement = toCache.get(i)!;
+          const replacement = toCache.get(i) as string;

          result += replacement;

@@ -361,22 +318,25 @@ export const splitVersion = (s: NixValue): NixValue => {
  return components;
 };

-export const traceVerbose = (e1: NixValue, e2: NixValue): never => {
-  throw new Error("Not implemented: traceVerbose");
+export const traceVerbose =
+  (_e1: NixValue) =>
+  (e2: NixValue): NixStrictValue => {
+    // TODO: implement traceVerbose
+    return force(e2);
  };

-export const tryEval = (e: NixValue): { success: NixBool; value: NixStrictValue } => {
+export const tryEval = (e: NixValue): NixAttrs => {
  try {
-    return {
-      success: true,
-      value: force(e),
-    };
+    return new Map<string, NixValue>([
+      ["success", true],
+      ["value", force(e)],
+    ]);
  } catch (err) {
    if (err instanceof CatchableError) {
-      return {
-        success: false,
-        value: false,
-      };
+      return new Map<string, NixValue>([
+        ["success", false],
+        ["value", false],
+      ]);
    } else {
      throw err;
    }
--- a/nix-js/runtime-ts/src/builtins/path.ts
+++ b/nix-js/runtime-ts/src/builtins/path.ts
@@ -1,13 +1,9 @@
-/**
- * Path-related builtin functions
- */
-
-import type { NixValue, NixString, NixPath } from "../types";
-import { isNixPath, isStringWithContext } from "../types";
-import { force } from "../thunk";
 import { mkPath } from "../path";
-import { coerceToString, StringCoercionMode, coerceToPath } from "./conversion";
 import { mkStringWithContext, type NixStringContext } from "../string-context";
+import { force } from "../thunk";
+import type { NixPath, NixString, NixValue } from "../types";
+import { isNixPath } from "../types";
+import { coerceToPath, coerceToString, StringCoercionMode } from "./conversion";

 /**
 * builtins.baseNameOf
@@ -90,21 +86,8 @@ export const dirOf = (s: NixValue): NixPath | NixString => {
  }

  // String input → string output
-  const strValue: NixString = coerceToString(s, StringCoercionMode.Base, false) as NixString;
-
-  let pathStr: string;
-  let hasContext = false;
-  let originalContext: Set<string> | undefined;
-
-  if (typeof strValue === "string") {
-    pathStr = strValue;
-  } else if (isStringWithContext(strValue)) {
-    pathStr = strValue.value;
-    hasContext = strValue.context.size > 0;
-    originalContext = strValue.context;
-  } else {
-    pathStr = strValue as string;
-  }
+  const outContext: NixStringContext = new Set();
+  const pathStr = coerceToString(s, StringCoercionMode.Base, false, outContext);

  const lastSlash = pathStr.lastIndexOf("/");

@@ -117,9 +100,8 @@ export const dirOf = (s: NixValue): NixPath | NixString => {

  const result = pathStr.slice(0, lastSlash);

-  // Preserve string context if present
-  if (hasContext && originalContext) {
-    return mkStringWithContext(result, originalContext);
+  if (outContext.size > 0) {
+    return mkStringWithContext(result, outContext);
  }

  return result;
--- a/nix-js/runtime-ts/src/builtins/string.ts
+++ b/nix-js/runtime-ts/src/builtins/string.ts
@@ -1,29 +1,15 @@
-/**
- * String operation builtin functions
- */
-
-import type { NixInt, NixValue, NixString } from "../types";
-import { forceStringValue, forceList, forceInt, forceString } from "../type-assert";
-import { coerceToString, StringCoercionMode } from "./conversion";
 import {
-  type NixStringContext,
-  getStringValue,
  getStringContext,
+  getStringValue,
  mkStringWithContext,
+  type NixStringContext,
 } from "../string-context";
+import { forceInt, forceList, forceString, forceStringValue } from "../type-assert";
+import type { NixInt, NixString, NixValue } from "../types";
+import { coerceToString, StringCoercionMode } from "./conversion";

 export const stringLength = (e: NixValue): NixInt => BigInt(forceStringValue(e).length);

-/**
- * builtins.substring - Extract substring while preserving string context
- *
- * IMPORTANT: String context must be preserved from the source string.
- * This matches Lix behavior where substring operations maintain references
- * to store paths and derivations.
- *
- * Special case: substring 0 0 str can be used idiomatically to capture
- * string context efficiently without copying the string value.
- */
 export const substring =
  (start: NixValue) =>
  (len: NixValue) =>
@@ -55,13 +41,6 @@ export const substring =
    return mkStringWithContext(result, context);
  };

-/**
- * builtins.concatStringsSep - Concatenate strings with separator, merging contexts
- *
- * IMPORTANT: String context must be collected from both the separator and all
- * list elements, then merged into the result. This ensures that store path
- * references are preserved when building paths like "/nix/store/xxx/bin:/nix/store/yyy/bin".
- */
 export const concatStringsSep =
  (sep: NixValue) =>
  (list: NixValue): NixString => {
--- a/nix-js/runtime-ts/src/builtins/type-check.ts
+++ b/nix-js/runtime-ts/src/builtins/type-check.ts
@@ -1,12 +1,6 @@
-/**
- * Type checking builtin functions
- */
-
 import {
-  HAS_CONTEXT,
  isNixPath,
  isStringWithContext,
-  type NixPath,
  type NixAttrs,
  type NixBool,
  type NixFloat,
@@ -14,23 +8,17 @@ import {
  type NixInt,
  type NixList,
  type NixNull,
-  type NixString,
+  type NixPath,
  type NixStrictValue,
+  type NixString,
 } from "../types";

-/**
- * Check if a value is a Nix string (plain string or StringWithContext)
- * This works on already-forced values (NixStrictValue).
- */
 export const isNixString = (v: NixStrictValue): v is NixString => {
  return typeof v === "string" || isStringWithContext(v);
 };

 export const isAttrs = (e: NixStrictValue): e is NixAttrs => {
-  const val = e;
-  return (
-    typeof val === "object" && !Array.isArray(val) && val !== null && !(HAS_CONTEXT in val) && !isPath(val)
-  );
+  return e instanceof Map;
 };

 export const isBool = (e: NixStrictValue): e is NixBool => typeof e === "boolean";
@@ -68,7 +56,7 @@ export const typeOf = (e: NixStrictValue): NixType => {
  if (isNixString(e)) return "string";
  if (isNixPath(e)) return "path";
  if (Array.isArray(e)) return "list";
-  if (typeof e === "object") return "set";
+  if (e instanceof Map) return "set";
  if (typeof e === "function") return "lambda";

  throw new TypeError(`Unknown Nix type: ${typeof e}`);
--- a/nix-js/runtime-ts/src/conversion.ts
+++ b/nix-js/runtime-ts/src/conversion.ts
@@ -1,83 +0,0 @@
-import { HAS_CONTEXT, NixStringContext } from "./string-context";
-import { force, isThunk } from "./thunk";
-import type { NixValue } from "./types";
-import { isStringWithContext, IS_PATH } from "./types";
-
-export const nixValueToJson = (
-  value: NixValue,
-  strict: boolean,
-  outContext: NixStringContext,
-  copyToStore: boolean,
-  seen: Set<NixValue> = new Set(),
-): any => {
-  const v = strict ? force(value) : value;
-
-  if (isThunk(v) || typeof v === "function")
-    throw new Error(`cannot convert ${isThunk(v) ? "thunk" : "lambda"} to JSON`);
-  if (v === null) return null;
-  if (typeof v === "bigint") {
-    const num = Number(v);
-    if (v > Number.MAX_SAFE_INTEGER || v < Number.MIN_SAFE_INTEGER) {
-      console.warn(`integer ${v} exceeds safe range, precision may be lost`);
-    }
-    return num;
-  }
-  if (typeof v === "number") return v;
-  if (typeof v === "boolean") return v;
-  if (typeof v === "string") return v;
-  if (typeof v === "object" && HAS_CONTEXT in v) {
-    for (const elem of v.context) {
-      outContext.add(elem);
-    }
-    return v.value;
-  }
-  if (typeof v === "object" && IS_PATH in v) {
-    if (copyToStore) {
-      const storePath = Deno.core.ops.op_copy_path_to_store(v.value);
-      outContext.add(storePath);
-      return storePath;
-    } else {
-      return v.value;
-    }
-  }
-
-  // FIXME: is this check necessary?
-  // if (seen.has(v)) {
-  //   throw new Error("cycle detected in toJSON");
-  // } else {
-  //   seen.add(v)
-  // }
-
-  if (Array.isArray(v)) {
-    return v.map((item) => nixValueToJson(item, strict, outContext, copyToStore, seen));
-  }
-
-  // NixAttrs
-  if ("__toString" in v && typeof force(v.__toString) === "function") {
-    const toStringMethod = force(v.__toString) as (self: typeof v) => NixValue;
-    const result = force(toStringMethod(v));
-    if (typeof result === "string") {
-      return result;
-    }
-    if (isStringWithContext(result)) {
-      if (outContext) {
-        for (const elem of result.context) {
-          outContext.add(elem);
-        }
-      }
-      return result.value;
-    }
-    return nixValueToJson(result, strict, outContext, copyToStore, seen);
-  }
-
-  if ("outPath" in v) {
-    return nixValueToJson(v.outPath, strict, outContext, copyToStore,seen);
-  }
-
-  const result: Record<string, any> = {};
-  const keys = Object.keys(v).sort();
-  for (const key of keys) {
-    result[key] = nixValueToJson(v[key], strict, outContext, copyToStore, seen);
-  }
-  return result;
-};
--- a/nix-js/runtime-ts/src/derivation-helpers.ts
+++ b/nix-js/runtime-ts/src/derivation-helpers.ts
@@ -1,106 +0,0 @@
-export interface OutputInfo {
-  path: string;
-  hashAlgo: string;
-  hash: string;
-}
-
-export interface DerivationData {
-  name: string;
-  outputs: Map<string, OutputInfo>;
-  inputDrvs: Map<string, Set<string>>;
-  inputSrcs: Set<string>;
-  platform: string;
-  builder: string;
-  args: string[];
-  env: Map<string, string>;
-}
-
-export const escapeString = (s: string): string => {
-  let result = "";
-  for (const char of s) {
-    switch (char) {
-      case '"':
-        result += '\\"';
-        break;
-      case "\\":
-        result += "\\\\";
-        break;
-      case "\n":
-        result += "\\n";
-        break;
-      case "\r":
-        result += "\\r";
-        break;
-      case "\t":
-        result += "\\t";
-        break;
-      default:
-        result += char;
-    }
-  }
-  return `"${result}"`;
-};
-
-const quoteString = (s: string): string => `"${s}"`;
-
-const cmpByKey = <T>(a: [string, T], b: [string, T]): number => (a[0] < b[0] ? -1 : a[0] > b[0] ? 1 : 0);
-
-export const generateAterm = (drv: DerivationData): string => {
-  const outputEntries: string[] = [];
-  const sortedOutputs = Array.from(drv.outputs.entries()).sort(cmpByKey);
-  for (const [name, info] of sortedOutputs) {
-    outputEntries.push(
-      `(${quoteString(name)},${quoteString(info.path)},${quoteString(info.hashAlgo)},${quoteString(info.hash)})`,
-    );
-  }
-  const outputs = outputEntries.join(",");
-
-  const inputDrvEntries: string[] = [];
-  const sortedInputDrvs = Array.from(drv.inputDrvs.entries()).sort(cmpByKey);
-  for (const [drvPath, outputs] of sortedInputDrvs) {
-    const sortedOuts = Array.from(outputs).sort();
-    const outList = `[${sortedOuts.map(quoteString).join(",")}]`;
-    inputDrvEntries.push(`(${quoteString(drvPath)},${outList})`);
-  }
-  const inputDrvs = inputDrvEntries.join(",");
-
-  const sortedInputSrcs = Array.from(drv.inputSrcs).sort();
-  const inputSrcs = sortedInputSrcs.map(quoteString).join(",");
-
-  const args = drv.args.map(escapeString).join(",");
-  const envs = Array.from(drv.env.entries())
-    .sort(cmpByKey)
-    .map(([k, v]) => `(${escapeString(k)},${escapeString(v)})`);
-
-  return `Derive([${outputs}],[${inputDrvs}],[${inputSrcs}],${quoteString(drv.platform)},${escapeString(drv.builder)},[${args}],[${envs}])`;
-};
-
-export const generateAtermModulo = (drv: DerivationData, inputDrvHashes: Map<string, string>): string => {
-  const outputEntries: string[] = [];
-  const sortedOutputs = Array.from(drv.outputs.entries()).sort(cmpByKey);
-  for (const [name, info] of sortedOutputs) {
-    outputEntries.push(
-      `(${quoteString(name)},${quoteString(info.path)},${quoteString(info.hashAlgo)},${quoteString(info.hash)})`,
-    );
-  }
-  const outputs = outputEntries.join(",");
-
-  const inputDrvEntries: string[] = [];
-  const sortedInputDrvHashes = Array.from(inputDrvHashes.entries()).sort(cmpByKey);
-  for (const [drvHash, outputs] of sortedInputDrvHashes) {
-    const sortedOuts = outputs.split(",").sort();
-    const outList = `[${sortedOuts.map(quoteString).join(",")}]`;
-    inputDrvEntries.push(`(${quoteString(drvHash)},${outList})`);
-  }
-  const inputDrvs = inputDrvEntries.join(",");
-
-  const sortedInputSrcs = Array.from(drv.inputSrcs).sort();
-  const inputSrcs = sortedInputSrcs.map(quoteString).join(",");
-
-  const args = drv.args.map(escapeString).join(",");
-  const envs = Array.from(drv.env.entries())
-    .sort(cmpByKey)
-    .map(([k, v]) => `(${escapeString(k)},${escapeString(v)})`);
-
-  return `Derive([${outputs}],[${inputDrvs}],[${inputSrcs}],${quoteString(drv.platform)},${escapeString(drv.builder)},[${args}],[${envs}])`;
-};
--- a/nix-js/runtime-ts/src/helpers.ts
+++ b/nix-js/runtime-ts/src/helpers.ts
@@ -1,18 +1,14 @@
-/**
- * Helper functions for nix-js runtime
- */
-
-import type { NixValue, NixAttrs, NixBool, NixString, NixPath } from "./types";
-import { forceAttrs, forceBool, forceFunction, forceStringValue } from "./type-assert";
-import { isAttrs, typeOf } from "./builtins/type-check";
 import { coerceToString, StringCoercionMode } from "./builtins/conversion";
-import { type NixStringContext, mkStringWithContext, isStringWithContext } from "./string-context";
-import { force } from "./thunk";
+import { isAttrs, typeOf } from "./builtins/type-check";
 import { mkPath } from "./path";
+import { isStringWithContext, mkStringWithContext, type NixStringContext } from "./string-context";
+import { force } from "./thunk";
+import { forceAttrs, forceBool, forceFunction, forceStringNoCtx, forceStringValue } from "./type-assert";
+import type { NixAttrs, NixBool, NixPath, NixString, NixValue } from "./types";
 import { CatchableError, isNixPath } from "./types";

 interface StackFrame {
-  span: string;
+  span: number;
  message: string;
 }

@@ -36,35 +32,18 @@ function enrichError(error: unknown): Error {
  return err;
 }

-export const getTos = (): string => {
-  const tos = callStack[callStack.length - 2];
-  const { file, line, column } = Deno.core.ops.op_decode_span(tos.span);
-  return `${tos.message} at ${file}:${line}:${column}`;
-};
-
-/**
- * Push an error context onto the stack
- * Used for tracking evaluation context (e.g., "while evaluating the condition")
- */
-export const pushContext = (message: string, span: string): void => {
+const pushContext = (message: string, span: number): void => {
  if (callStack.length >= MAX_STACK_DEPTH) {
    callStack.shift();
  }
  callStack.push({ span, message });
 };

-/**
- * Pop an error context from the stack
- */
-export const popContext = (): void => {
+const popContext = (): void => {
  callStack.pop();
 };

-/**
- * Execute a function with error context tracking
- * Automatically pushes context before execution and pops after
- */
-export const withContext = <T>(message: string, span: string, fn: () => T): T => {
+export const withContext = <T>(message: string, span: number, fn: () => T): T => {
  pushContext(message, span);
  try {
    return fn();
@@ -149,13 +128,6 @@ export const concatStringsWithContext = (parts: NixValue[], forceString: boolean
  return mkStringWithContext(value, context);
 };

-/**
- * Resolve a path (handles both absolute and relative paths)
- * For relative paths, resolves against current import stack
- *
- * @param path - Path string (may be relative or absolute)
- * @returns NixPath object with absolute path
- */
 export const resolvePath = (currentDir: string, path: NixValue): NixPath => {
  const forced = force(path);
  let pathStr: string;
@@ -170,86 +142,92 @@ export const resolvePath = (currentDir: string, path: NixValue): NixPath => {
  return mkPath(resolved);
 };

-export const select = (obj: NixValue, attrpath: NixValue[], span?: string): NixValue => {
-  if (span) {
-    const pathStrings = attrpath.map((a) => forceStringValue(a));
-    const path = pathStrings.join(".");
-    const message = path ? `while selecting attribute [${path}]` : "while selecting attribute";
-
+export const select = (obj: NixValue, attrpath: NixValue[], span?: number): NixValue => {
+  if (span !== undefined) {
    if (callStack.length >= MAX_STACK_DEPTH) {
      callStack.shift();
    }
-    callStack.push({ span, message });
+    const frame: StackFrame = { span, message: "while selecting attribute" };
+    callStack.push(frame);
    try {
-      return select_impl(obj, attrpath);
+      return selectImpl(obj, attrpath);
    } catch (error) {
+      try {
+        const path = attrpath.map((a) => forceStringValue(a)).join(".");
+        if (path) frame.message = `while selecting attribute [${path}]`;
+      } catch {
+        throw enrichError(error);
+      }
      throw enrichError(error);
    } finally {
      callStack.pop();
    }
  } else {
-    return select_impl(obj, attrpath);
+    return selectImpl(obj, attrpath);
  }
 };

-function select_impl(obj: NixValue, attrpath: NixValue[]): NixValue {
+function selectImpl(obj: NixValue, attrpath: NixValue[]): NixValue {
  let attrs = forceAttrs(obj);

-  for (const attr of attrpath.slice(0, -1)) {
-    const key = forceStringValue(attr);
-    if (!(key in attrs)) {
+  for (let i = 0; i < attrpath.length - 1; i++) {
+    const key = forceStringValue(attrpath[i]);
+    if (!attrs.has(key)) {
      throw new Error(`Attribute '${key}' not found`);
    }
-    const cur = forceAttrs(attrs[forceStringValue(attr)]);
+    const cur = forceAttrs(attrs.get(key) as NixValue);
    attrs = cur;
  }

  const last = forceStringValue(attrpath[attrpath.length - 1]);
-  if (!(last in attrs)) {
+  if (!attrs.has(last)) {
    throw new Error(`Attribute '${last}' not found`);
  }
-  return attrs[last];
+  return attrs.get(last) as NixValue;
 }

 export const selectWithDefault = (
  obj: NixValue,
  attrpath: NixValue[],
-  default_val: NixValue,
-  span?: string,
+  defaultVal: NixValue,
+  span?: number,
 ): NixValue => {
-  if (span) {
-    const pathStrings = attrpath.map((a) => forceStringValue(a));
-    const path = pathStrings.join(".");
-    const message = path ? `while selecting attribute [${path}]` : "while selecting attribute";
-
+  if (span !== undefined) {
    if (callStack.length >= MAX_STACK_DEPTH) {
      callStack.shift();
    }
-    callStack.push({ span, message });
+    const frame: StackFrame = { span, message: "while selecting attribute" };
+    callStack.push(frame);
    try {
-      return selectWithDefault_impl(obj, attrpath, default_val);
+      return selectWithDefaultImpl(obj, attrpath, defaultVal);
    } catch (error) {
+      try {
+        const path = attrpath.map((a) => forceStringValue(a)).join(".");
+        if (path) frame.message = `while selecting attribute [${path}]`;
+      } catch {
+        throw enrichError(error);
+      }
      throw enrichError(error);
    } finally {
      callStack.pop();
    }
  } else {
-    return selectWithDefault_impl(obj, attrpath, default_val);
+    return selectWithDefaultImpl(obj, attrpath, defaultVal);
  }
 };

-function selectWithDefault_impl(obj: NixValue, attrpath: NixValue[], defaultVal: NixValue): NixValue {
+function selectWithDefaultImpl(obj: NixValue, attrpath: NixValue[], defaultVal: NixValue): NixValue {
  let attrs = force(obj);
  if (!isAttrs(attrs)) {
    return defaultVal;
  }

-  for (const attr of attrpath.slice(0, -1)) {
-    const key = forceStringValue(attr);
-    if (!(key in attrs)) {
+  for (let i = 0; i < attrpath.length - 1; i++) {
+    const key = forceStringValue(attrpath[i]);
+    if (!attrs.has(key)) {
      return defaultVal;
    }
-    const cur = force(attrs[key]);
+    const cur = force(attrs.get(key) as NixValue);
    if (!isAttrs(cur)) {
      return defaultVal;
    }
@@ -257,8 +235,8 @@ function selectWithDefault_impl(obj: NixValue, attrpath: NixValue[], defaultVal:
  }

  const last = forceStringValue(attrpath[attrpath.length - 1]);
-  if (last in attrs) {
-    return attrs[last];
+  if (attrs.has(last)) {
+    return attrs.get(last) as NixValue;
  }
  return defaultVal;
 }
@@ -270,97 +248,53 @@ export const hasAttr = (obj: NixValue, attrpath: NixValue[]): NixBool => {
  }
  let attrs = forced;

-  for (const attr of attrpath.slice(0, -1)) {
-    const cur = force(attrs[forceStringValue(attr)]);
+  for (let i = 0; i < attrpath.length - 1; i++) {
+    const key = forceStringNoCtx(attrpath[i]);
+    if (!attrs.has(key)) {
+      return false;
+    }
+    const cur = force(attrs.get(key) as NixValue);
    if (!isAttrs(cur)) {
      return false;
    }
    attrs = cur;
  }

-  return forceStringValue(attrpath[attrpath.length - 1]) in attrs;
+  return attrs.has(forceStringValue(attrpath[attrpath.length - 1]));
 };

-/**
- * Validate function parameters
- * Used for pattern matching in function parameters
- *
- * Example: { a, b ? 1, ... }: ...
- * - required: ["a"]
- * - allowed: ["a", "b"] (or null if ellipsis "..." present)
- *
- * @param arg - Argument object to validate
- * @param required - Array of required parameter names (or null)
- * @param allowed - Array of allowed parameter names (or null for ellipsis)
- * @returns The forced argument object
- * @throws Error if required param missing or unexpected param present
- */
-export const validateParams = (
-  arg: NixValue,
-  required: string[] | null,
-  allowed: string[] | null,
-): NixAttrs => {
-  const forced_arg = forceAttrs(arg);
-
-  // Check required parameters
-  if (required) {
-    for (const key of required) {
-      if (!Object.hasOwn(forced_arg, key)) {
-        throw new Error(`Function called without required argument '${key}'`);
-      }
-    }
-  }
-
-  // Check allowed parameters (if not using ellipsis)
-  if (allowed) {
-    const allowed_set = new Set(allowed);
-    for (const key in forced_arg) {
-      if (!allowed_set.has(key)) {
-        throw new Error(`Function called with unexpected argument '${key}'`);
-      }
-    }
-  }
-
-  return forced_arg;
-};
-
-export const call = (func: NixValue, arg: NixValue, span?: string): NixValue => {
-  if (span) {
+export const call = (func: NixValue, arg: NixValue, span?: number): NixValue => {
+  if (span !== undefined) {
    if (callStack.length >= MAX_STACK_DEPTH) {
      callStack.shift();
    }
    callStack.push({ span, message: "from call site" });
    try {
-      return call_impl(func, arg);
+      return callImpl(func, arg);
    } catch (error) {
      throw enrichError(error);
    } finally {
      callStack.pop();
    }
  } else {
-    return call_impl(func, arg);
+    return callImpl(func, arg);
  }
 };

-function call_impl(func: NixValue, arg: NixValue): NixValue {
-  const forcedFunc = force(func);
-  if (typeof forcedFunc === "function") {
-    forcedFunc.args?.check(arg);
-    return forcedFunc(arg);
+function callImpl(func: NixValue, arg: NixValue): NixValue {
+  const forced = force(func);
+  if (typeof forced === "function") {
+    forced.args?.check(arg);
+    return forced(arg);
  }
-  if (
-    typeof forcedFunc === "object" &&
-    !Array.isArray(forcedFunc) &&
-    forcedFunc !== null &&
-    "__functor" in forcedFunc
-  ) {
-    const functor = forceFunction(forcedFunc.__functor);
-    return call(functor(forcedFunc), arg);
+  if (forced instanceof Map && forced.has("__functor")) {
+    const functor = forceFunction(forced.get("__functor") as NixValue);
+    return call(callImpl(functor, forced), arg);
  }
-  throw new Error(`attempt to call something which is not a function but ${typeOf(forcedFunc)}`);
+  throw new Error(`attempt to call something which is not a function but ${typeOf(forced)}`);
 }

-export const assert = (assertion: NixValue, expr: NixValue, assertionRaw: string, span: string): NixValue => {
+export const assert = (assertion: NixValue, expr: NixValue, assertionRaw: string, span: number): NixValue => {
  if (forceBool(assertion)) {
    return expr;
  }
@@ -370,14 +304,7 @@ export const assert = (assertion: NixValue, expr: NixValue, assertionRaw: string
  throw "unreachable";
 };

-export const ifFunc = (cond: NixValue, consq: NixValue, alter: NixValue) => {
-  if (forceBool(cond)) {
-    return consq;
-  }
-  return alter;
-};
-
-export const mkPos = (span: string): NixAttrs => {
+export const mkPos = (span: number): NixAttrs => {
  return Deno.core.ops.op_decode_span(span);
 };

@@ -386,12 +313,12 @@ interface WithScope {
  last: WithScope | null;
 }

-export const lookupWith = (name: string, withScope: WithScope | null): NixValue => {
-  let current = withScope;
+export const lookupWith = (name: string, withScope: WithScope): NixValue => {
+  let current: WithScope | null = withScope;
  while (current !== null) {
    const attrs = forceAttrs(current.env);
-    if (name in attrs) {
-      return attrs[name];
+    if (attrs.has(name)) {
+      return attrs.get(name) as NixValue;
    }
    current = current.last;
  }
--- a/nix-js/runtime-ts/src/index.ts
+++ b/nix-js/runtime-ts/src/index.ts
@@ -4,88 +4,95 @@
 * All functionality is exported via the global `Nix` object
 */

+import { builtins, PRIMOP_METADATA } from "./builtins";
 import {
-  createThunk,
-  force,
-  isThunk,
-  IS_THUNK,
-  DEBUG_THUNKS,
-  forceDeep,
-  IS_CYCLE,
-  forceShallow,
-} from "./thunk";
-import {
+  assert,
+  call,
+  concatStringsWithContext,
+  hasAttr,
+  lookupWith,
+  mkPos,
+  resolvePath,
  select,
  selectWithDefault,
-  validateParams,
-  resolvePath,
-  hasAttr,
-  concatStringsWithContext,
-  call,
-  assert,
-  pushContext,
-  popContext,
-  withContext,
-  mkPos,
-  lookupWith,
 } from "./helpers";
 import { op } from "./operators";
-import { builtins, PRIMOP_METADATA } from "./builtins";
-import { coerceToString, StringCoercionMode } from "./builtins/conversion";
 import { HAS_CONTEXT } from "./string-context";
-import { IS_PATH, mkAttrs, mkFunction, mkAttrsWithPos, ATTR_POSITIONS, NixValue } from "./types";
+import { createThunk, DEBUG_THUNKS, force, forceDeep, forceShallow, IS_CYCLE, IS_THUNK } from "./thunk";
 import { forceBool } from "./type-assert";
+import { IS_PATH, mkAttrs, mkFunction, type NixValue } from "./types";
+import { execBytecode, execBytecodeScoped, vmStrings, vmConstants } from "./vm";

 export type NixRuntime = typeof Nix;

-const replBindings: Record<string, NixValue> = {};
+const replBindings: Map<string, NixValue> = new Map();

-/**
- * The global Nix runtime object
- */
 export const Nix = {
-  createThunk,
-  force,
-  forceShallow,
-  forceDeep,
-  forceBool,
-  isThunk,
  IS_THUNK,
  IS_CYCLE,
  HAS_CONTEXT,
  IS_PATH,
+  PRIMOP_METADATA,
  DEBUG_THUNKS,

+  createThunk,
+  force,
+  forceBool,
+  forceShallow,
+  forceDeep,
+
  assert,
  call,
  hasAttr,
  select,
  selectWithDefault,
  lookupWith,
-  validateParams,
  resolvePath,
-  coerceToString,
  concatStringsWithContext,
-  StringCoercionMode,
  mkAttrs,
-  mkAttrsWithPos,
  mkFunction,
  mkPos,
-  ATTR_POSITIONS,
-
-  pushContext,
-  popContext,
-  withContext,

  op,
  builtins,
-  PRIMOP_METADATA,
+
+  strings: vmStrings,
+  constants: vmConstants,
+  execBytecode,
+  execBytecodeScoped,

  replBindings,
  setReplBinding: (name: string, value: NixValue) => {
-    replBindings[name] = value;
+    replBindings.set(name, value);
  },
-  getReplBinding: (name: string) => replBindings[name],
+  getReplBinding: (name: string) => replBindings.get(name),
 };

 globalThis.Nix = Nix;
+globalThis.$t = createThunk;
+globalThis.$f = force;
+globalThis.$fb = forceBool;
+globalThis.$a = assert;
+globalThis.$c = call;
+globalThis.$h = hasAttr;
+globalThis.$s = select;
+globalThis.$sd = selectWithDefault;
+globalThis.$l = lookupWith;
+globalThis.$r = resolvePath;
+globalThis.$cs = concatStringsWithContext;
+globalThis.$ma = mkAttrs;
+globalThis.$mf = mkFunction;
+globalThis.$mp = mkPos;
+globalThis.$gb = Nix.getReplBinding;
+
+globalThis.$oa = op.add;
+globalThis.$os = op.sub;
+globalThis.$om = op.mul;
+globalThis.$od = op.div;
+globalThis.$oe = op.eq;
+globalThis.$ol = op.lt;
+globalThis.$og = op.gt;
+globalThis.$oc = op.concat;
+globalThis.$ou = op.update;
+globalThis.$b = builtins;
+globalThis.$e = new Map();
--- a/nix-js/runtime-ts/src/operators.ts
+++ b/nix-js/runtime-ts/src/operators.ts
@@ -1,37 +1,27 @@
-/**
- * Nix operators module
- * Implements all binary and unary operators used by codegen
- */
-
-import type { NixValue, NixList, NixAttrs, NixString, NixPath } from "./types";
-import { isNixPath } from "./types";
-import { force } from "./thunk";
-import { forceNumeric, forceList, forceAttrs, coerceNumeric } from "./type-assert";
+import { coerceToString, StringCoercionMode } from "./builtins/conversion";
+import { isNixString, typeOf } from "./builtins/type-check";
+import { mkPath } from "./path";
 import {
-  type NixStringContext,
-  getStringValue,
  getStringContext,
+  getStringValue,
  mergeContexts,
  mkStringWithContext,
+  type NixStringContext,
 } from "./string-context";
-import { coerceToString, StringCoercionMode } from "./builtins/conversion";
-import { mkPath } from "./path";
-import { typeOf, isNixString } from "./builtins/type-check";
+import { force } from "./thunk";
+import { coerceNumeric, forceAttrs, forceBool, forceList, forceNumeric } from "./type-assert";
+import type { NixAttrs, NixList, NixPath, NixString, NixValue } from "./types";
+import { isNixPath } from "./types";

 const canCoerceToString = (v: NixValue): boolean => {
  const forced = force(v);
  if (isNixString(forced)) return true;
-  if (typeof forced === "object" && forced !== null && !Array.isArray(forced)) {
-    if ("outPath" in forced || "__toString" in forced) return true;
+  if (forced instanceof Map) {
+    if (forced.has("outPath") || forced.has("__toString")) return true;
  }
  return false;
 };

-/**
- * Compare two values, similar to Nix's CompareValues.
- * Returns: -1 if a < b, 0 if a == b, 1 if a > b
- * Throws TypeError for incomparable types.
- */
 export const compareValues = (a: NixValue, b: NixValue): -1 | 0 | 1 => {
  const av = force(a);
  const bv = force(b);
@@ -54,32 +44,29 @@ export const compareValues = (a: NixValue, b: NixValue): -1 | 0 | 1 => {
    throw new TypeError(`cannot compare ${typeOf(av)} with ${typeOf(bv)}`);
  }

-  // Int and float comparison
  if (typeA === "int" || typeA === "float") {
-    return av! < bv! ? -1 : av === bv ? 0 : 1;
+    return (av as never) < (bv as never) ? -1 : av === bv ? 0 : 1;
  }

-  // String comparison (handles both plain strings and StringWithContext)
  if (typeA === "string") {
    const strA = getStringValue(av as NixString);
    const strB = getStringValue(bv as NixString);
    return strA < strB ? -1 : strA > strB ? 1 : 0;
  }

-  // Path comparison
  if (typeA === "path") {
    const aPath = av as NixPath;
    const bPath = bv as NixPath;
    return aPath.value < bPath.value ? -1 : aPath.value > bPath.value ? 1 : 0;
  }

-  // List comparison (lexicographic)
  if (typeA === "list") {
    const aList = av as NixList;
    const bList = bv as NixList;
    for (let i = 0; ; i++) {
+      // Equal if same length, else aList > bList
      if (i === bList.length) {
-        return i === aList.length ? 0 : 1; // Equal if same length, else aList > bList
+        return i === aList.length ? 0 : 1;
      } else if (i === aList.length) {
        return -1; // aList < bList
      } else if (!op.eq(aList[i], bList[i])) {
@@ -94,10 +81,6 @@ export const compareValues = (a: NixValue, b: NixValue): -1 | 0 | 1 => {
  );
 };

-/**
- * Operator object exported as Nix.op
- * All operators referenced by codegen (e.g., Nix.op.add, Nix.op.eq)
- */
 export const op = {
  add: (a: NixValue, b: NixValue): bigint | number | NixString | NixPath => {
    const av = force(a);
@@ -109,15 +92,14 @@ export const op = {
        const strB = getStringValue(bv);
        const ctxB = getStringContext(bv);

-        // Lix constraint: cannot append string with store context to path
        if (ctxB.size > 0) {
          throw new TypeError("a string that refers to a store path cannot be appended to a path");
        }

-        // Concatenate paths
        return mkPath(av.value + strB);
      }

+      // FIXME: handle corepkgs
      // path + path: concatenate
      if (isNixPath(bv)) {
        return mkPath(av.value + bv.value);
@@ -138,6 +120,7 @@ export const op = {

    // String concatenation
    if (isNixString(av) && isNixString(bv)) {
+      // Merge string context
      const strA = getStringValue(av);
      const strB = getStringValue(bv);
      const ctxA = getStringContext(av);
@@ -162,19 +145,19 @@ export const op = {
      return mkStringWithContext(result, context);
    }

-    // Numeric addition
+    // Perform numeric addition otherwise
    const [numA, numB] = coerceNumeric(forceNumeric(a), forceNumeric(b));
-    return (numA as any) + (numB as any);
+    return (numA as never) + (numB as never);
  },

  sub: (a: NixValue, b: NixValue): bigint | number => {
    const [av, bv] = coerceNumeric(forceNumeric(a), forceNumeric(b));
-    return (av as any) - (bv as any);
+    return (av as never) - (bv as never);
  },

  mul: (a: NixValue, b: NixValue): bigint | number => {
    const [av, bv] = coerceNumeric(forceNumeric(a), forceNumeric(b));
-    return (av as any) * (bv as any);
+    return (av as never) * (bv as never);
  },

  div: (a: NixValue, b: NixValue): bigint | number => {
@@ -184,7 +167,7 @@ export const op = {
      throw new RangeError("Division by zero");
    }

-    return (av as any) / (bv as any);
+    return (av as never) / (bv as never);
  },

  eq: (a: NixValue, b: NixValue): boolean => {
@@ -202,7 +185,6 @@ export const op = {
      return av === Number(bv);
    }

-    // Get type names for comparison (skip if already handled above)
    const typeA = typeOf(av);
    const typeB = typeOf(bv);

@@ -223,10 +205,12 @@ export const op = {
      return (av as NixPath).value === (bv as NixPath).value;
    }

-    if (Array.isArray(av) && Array.isArray(bv)) {
-      if (av.length !== bv.length) return false;
-      for (let i = 0; i < av.length; i++) {
-        if (!op.eq(av[i], bv[i])) return false;
+    if (typeA === "list") {
+      const aList = av as NixList;
+      const bList = bv as NixList;
+      if (aList.length !== bList.length) return false;
+      for (let i = 0; i < aList.length; i++) {
+        if (!op.eq(aList[i], bList[i])) return false;
      }
      return true;
    }
@@ -235,37 +219,30 @@ export const op = {
      const attrsA = av as NixAttrs;
      const attrsB = bv as NixAttrs;

-      // Derivation comparison: compare outPaths only
-      // Safe to force 'type' because it's always a string literal, never a computed value
-      if ("type" in attrsA && "type" in attrsB) {
-        const typeValA = force(attrsA.type);
-        const typeValB = force(attrsB.type);
+      if (attrsA.has("type") && attrsB.has("type")) {
+        const typeValA = force(attrsA.get("type") as NixValue);
+        const typeValB = force(attrsB.get("type") as NixValue);
        if (typeValA === "derivation" && typeValB === "derivation") {
-          if ("outPath" in attrsA && "outPath" in attrsB) {
-            return op.eq(attrsA.outPath, attrsB.outPath);
+          if (attrsA.has("outPath") && attrsB.has("outPath")) {
+            return op.eq(attrsA.get("outPath") as NixValue, attrsB.get("outPath") as NixValue);
          }
        }
      }

-      // Otherwise, compare attributes one by one
-      const keysA = Object.keys(attrsA).sort();
-      const keysB = Object.keys(attrsB).sort();
+      const keysA = Array.from(attrsA.keys()).sort();
+      const keysB = Array.from(attrsB.keys()).sort();

      if (keysA.length !== keysB.length) return false;

      for (let i = 0; i < keysA.length; i++) {
        if (keysA[i] !== keysB[i]) return false;
-        if (!op.eq(attrsA[keysA[i]], attrsB[keysB[i]])) return false;
+        if (!op.eq(attrsA.get(keysA[i]) as NixValue, attrsB.get(keysB[i]) as NixValue)) return false;
      }

      return true;
    }

-    // Functions are incomparable
-    if (typeof av === "function") {
-      return false;
-    }
-
+    // Other types are incomparable
    return false;
  },
  neq: (a: NixValue, b: NixValue): boolean => {
@@ -284,11 +261,25 @@ export const op = {
    return compareValues(a, b) >= 0;
  },

-  bnot: (a: NixValue): boolean => !force(a),
+  bnot: (a: NixValue): boolean => !forceBool(a),

  concat: (a: NixValue, b: NixValue): NixList => {
-    return Array.prototype.concat.call(forceList(a), forceList(b));
+    return forceList(a).concat(forceList(b));
  },

-  update: (a: NixValue, b: NixValue): NixAttrs => ({ ...forceAttrs(a), ...forceAttrs(b) }),
+  update: (a: NixValue, b: NixValue): NixAttrs => {
+    const mapA = forceAttrs(a);
+    const mapB = forceAttrs(b);
+    if (mapA.size === 0) {
+      return mapB;
+    }
+    if (mapB.size === 0) {
+      return mapA;
+    }
+    const result: NixAttrs = new Map(mapA);
+    for (const [k, v] of mapB) {
+      result.set(k, v);
+    }
+    return result;
+  },
 };
--- a/nix-js/runtime-ts/src/path.ts
+++ b/nix-js/runtime-ts/src/path.ts
@@ -1,4 +1,4 @@
-import { IS_PATH, type NixPath } from "./types";
+import { NixPath } from "./types";

 const canonicalizePath = (path: string): string => {
  const parts: string[] = [];
@@ -14,13 +14,11 @@ const canonicalizePath = (path: string): string => {
    const component = path.slice(i, j);
    i = j;

-    if (component === ".") {
-      continue;
-    } else if (component === "..") {
+    if (component === "..") {
      if (parts.length > 0) {
        parts.pop();
      }
-    } else {
+    } else if (component !== ".") {
      parts.push(component);
    }
  }
@@ -28,11 +26,11 @@ const canonicalizePath = (path: string): string => {
  if (parts.length === 0) {
    return "/";
  }
-  return "/" + parts.join("/");
+  return `/${parts.join("/")}`;
 };

 export const mkPath = (value: string): NixPath => {
-  return { [IS_PATH]: true, value: canonicalizePath(value) };
+  return new NixPath(canonicalizePath(value));
 };

 export const getPathValue = (p: NixPath): string => {
--- a/nix-js/runtime-ts/src/print.ts
+++ b/nix-js/runtime-ts/src/print.ts
@@ -1,7 +1,7 @@
-import { isThunk, IS_CYCLE } from "./thunk";
+import { getPrimopMetadata, isPrimop } from "./builtins/index";
 import { isStringWithContext } from "./string-context";
+import { IS_CYCLE, isThunk } from "./thunk";
 import { isNixPath, type NixValue } from "./types";
-import { is_primop, get_primop_metadata } from "./builtins/index";

 export const printValue = (value: NixValue, seen: WeakSet<object> = new WeakSet()): string => {
  if (isThunk(value)) {
@@ -29,8 +29,8 @@ export const printValue = (value: NixValue, seen: WeakSet<object> = new WeakSet(
  }

  if (typeof value === "function") {
-    if (is_primop(value)) {
-      const meta = get_primop_metadata(value);
+    if (isPrimop(value)) {
+      const meta = getPrimopMetadata(value);
      if (meta && meta.applied > 0) {
        return "<PRIMOP-APP>";
      }
@@ -39,16 +39,10 @@ export const printValue = (value: NixValue, seen: WeakSet<object> = new WeakSet(
    return "<LAMBDA>";
  }

-  if (typeof value === "object") {
-    if (IS_CYCLE in value && (value as any)[IS_CYCLE] === true) {
+  if (IS_CYCLE in value) {
    return "«repeated»";
  }

-    if (seen.has(value)) {
-      return "«repeated»";
-    }
-    seen.add(value);
-
  if (isNixPath(value)) {
    return value.value;
  }
@@ -58,17 +52,27 @@ export const printValue = (value: NixValue, seen: WeakSet<object> = new WeakSet(
  }

  if (Array.isArray(value)) {
+    if (value.length > 0) {
+      if (seen.has(value)) {
+        return "«repeated»";
+      }
+      seen.add(value);
+    }
    const items = value.map((v) => printValue(v, seen)).join(" ");
    return `[ ${items} ]`;
  }

-    const entries = Object.entries(value)
+  if (seen.has(value)) {
+    return "«repeated»";
+  }
+  if (value.size > 0) {
+    seen.add(value);
+  }
+
+  const entries = [...value.entries()]
    .map(([k, v]) => `${printSymbol(k)} = ${printValue(v, seen)};`)
    .join(" ");
  return `{${entries ? ` ${entries} ` : " "}}`;
-  }
-
-  return "<unknown>";
 };

 const printString = (s: string): string => {
@@ -94,7 +98,7 @@ const printString = (s: string): string => {
        result += c;
    }
  }
-  return result + '"';
+  return `${result}"`;
 };

 const SYMBOL_REGEX = /^[a-zA-Z_][a-zA-Z0-9_'-]*$/;
--- a/nix-js/runtime-ts/src/string-context.ts
+++ b/nix-js/runtime-ts/src/string-context.ts
@@ -1,29 +1,4 @@
-/**
- * String Context System for Nix
- *
- * String context tracks references to store paths and derivations within strings.
- * This is critical for Nix's dependency tracking - when a string containing a
- * store path is used in a derivation, that store path becomes a build dependency.
- *
- * Context Elements (encoded as strings):
- * - Opaque: Plain store path reference
- *   Format: "/nix/store/..."
- *   Example: "/nix/store/abc123-hello"
- *
- * - DrvDeep: Derivation with all outputs
- *   Format: "=/nix/store/...drv"
- *   Example: "=/nix/store/xyz789-hello.drv"
- *   Meaning: All outputs of this derivation and its closure
- *
- * - Built: Specific derivation output
- *   Format: "!<output>!/nix/store/...drv"
- *   Example: "!out!/nix/store/xyz789-hello.drv"
- *   Meaning: Specific output (e.g., "out", "dev", "lib") of this derivation
- *
- * This implementation matches Lix's NixStringContext system.
- */
-
-import { NixStrictValue } from "./types";
+import type { NixStrictValue } from "./types";

 export const HAS_CONTEXT = Symbol("HAS_CONTEXT");

@@ -47,18 +22,22 @@ export type StringContextElem = StringContextOpaque | StringContextDrvDeep | Str

 export type NixStringContext = Set<string>;

-export interface StringWithContext {
-  readonly [HAS_CONTEXT]: true;
+export class StringWithContext {
+  readonly [HAS_CONTEXT] = true as const;
  value: string;
  context: NixStringContext;
+  constructor(value: string, context: NixStringContext) {
+    this.value = value;
+    this.context = context;
+  }
 }

 export const isStringWithContext = (v: NixStrictValue): v is StringWithContext => {
-  return typeof v === "object" && v !== null && HAS_CONTEXT in v;
+  return v instanceof StringWithContext;
 };

 export const mkStringWithContext = (value: string, context: NixStringContext): StringWithContext => {
-  return { [HAS_CONTEXT]: true, value, context };
+  return new StringWithContext(value, context);
 };

 export const mkPlainString = (value: string): string => value;
@@ -70,11 +49,12 @@ export const getStringValue = (s: string | StringWithContext): string => {
  return s;
 };

+const emptyContext: NixStringContext = new Set();
 export const getStringContext = (s: string | StringWithContext): NixStringContext => {
  if (isStringWithContext(s)) {
    return s.context;
  }
-  return new Set();
+  return emptyContext;
 };

 export const mergeContexts = (...contexts: NixStringContext[]): NixStringContext => {
@@ -171,68 +151,3 @@ export const parseContextToInfoMap = (context: NixStringContext): Map<string, Pa

  return result;
 };
-
-/**
- * Extract input derivations and source paths from context
- *
- * IMPORTANT: Used by derivation builder to determine build dependencies.
- *
- * Returns:
- * - inputDrvs: Map of derivation paths to their required output names
- * - inputSrcs: Set of plain store paths (opaque) and drvDeep references
- *
- * Context type handling:
- * - Opaque: Added to inputSrcs
- * - DrvDeep: Computes FS closure (like Nix's computeFSClosure) - adds all paths
- *            in the dependency graph to inputSrcs, and all derivations with their
- *            outputs to inputDrvs
- * - Built: Added to inputDrvs with specific output name
- */
-export const extractInputDrvsAndSrcs = (
-  context: NixStringContext,
-): { inputDrvs: Map<string, Set<string>>; inputSrcs: Set<string> } => {
-  const inputDrvs = new Map<string, Set<string>>();
-  const inputSrcs = new Set<string>();
-
-  for (const encoded of context) {
-    const elem = decodeContextElem(encoded);
-    switch (elem.type) {
-      case "opaque":
-        inputSrcs.add(elem.path);
-        break;
-      case "drvDeep": {
-        const closure: {
-          input_drvs: [string, string[]][];
-          input_srcs: string[];
-        } = Deno.core.ops.op_compute_fs_closure(elem.drvPath);
-
-        for (const src of closure.input_srcs) {
-          inputSrcs.add(src);
-        }
-
-        for (const [drvPath, outputs] of closure.input_drvs) {
-          let existingOutputs = inputDrvs.get(drvPath);
-          if (!existingOutputs) {
-            existingOutputs = new Set<string>();
-            inputDrvs.set(drvPath, existingOutputs);
-          }
-          for (const output of outputs) {
-            existingOutputs.add(output);
-          }
-        }
-        break;
-      }
-      case "built": {
-        let outputs = inputDrvs.get(elem.drvPath);
-        if (!outputs) {
-          outputs = new Set<string>();
-          inputDrvs.set(elem.drvPath, outputs);
-        }
-        outputs.add(elem.output);
-        break;
-      }
-    }
-  }
-
-  return { inputDrvs, inputSrcs };
-};
--- a/nix-js/runtime-ts/src/thunk.ts
+++ b/nix-js/runtime-ts/src/thunk.ts
@@ -1,17 +1,8 @@
-/**
- * Lazy evaluation system for nix-js
- * Implements thunks for lazy evaluation of Nix expressions
- */
-
-import type { NixValue, NixThunkInterface, NixStrictValue } from "./types";
-import { HAS_CONTEXT } from "./string-context";
-import { IS_PATH } from "./types";
 import { isAttrs, isList } from "./builtins/type-check";
+import { StringWithContext } from "./string-context";
+import type { NixAttrs, NixStrictValue, NixValue } from "./types";
+import { NixPath } from "./types";

-/**
- * Symbol used to mark objects as thunks
- * This is exported to Rust via Nix.IS_THUNK
- */
 export const IS_THUNK = Symbol("is_thunk");

 const forceStack: NixThunk[] = [];
@@ -30,8 +21,7 @@ export const DEBUG_THUNKS = { enabled: true };
 * - Evaluating (blackhole): func is undefined, result is undefined
 * - Evaluated: func is undefined, result is defined
 */
-export class NixThunk implements NixThunkInterface {
-  [key: symbol]: any;
+export class NixThunk {
  readonly [IS_THUNK] = true as const;
  func: (() => NixValue) | undefined;
  result: NixStrictValue | undefined;
@@ -51,13 +41,8 @@ export class NixThunk implements NixThunkInterface {
  }
 }

-/**
- * Type guard to check if a value is a thunk
- * @param value - Value to check
- * @returns true if value is a NixThunk
- */
-export const isThunk = (value: NixValue): value is NixThunkInterface => {
-  return value !== null && typeof value === "object" && IS_THUNK in value && value[IS_THUNK] === true;
+export const isThunk = (value: NixValue): value is NixThunk => {
+  return value instanceof NixThunk;
 };

 /**
@@ -96,7 +81,7 @@ export const force = (value: NixValue): NixStrictValue => {
  }

  const thunk = value as NixThunk;
-  const func = thunk.func!;
+  const func = thunk.func as () => NixValue;
  thunk.func = undefined;

  if (DEBUG_THUNKS.enabled) {
@@ -126,25 +111,12 @@ export const force = (value: NixValue): NixStrictValue => {
  }
 };

-/**
- * Create a new thunk from a function
- * @param func - Function that produces a value when called
- * @param label - Optional label for debugging
- * @returns A new NixThunk wrapping the function
- */
-export const createThunk = (func: () => NixValue, label?: string): NixThunkInterface => {
+export const createThunk = (func: () => NixValue, label?: string): NixThunk => {
  return new NixThunk(func, label);
 };

-/**
- * Symbol to mark cyclic references detected during deep forcing
- */
 export const IS_CYCLE = Symbol("is_cycle");
-
-/**
- * Marker object for cyclic references
- */
-export const CYCLE_MARKER = { [IS_CYCLE]: true };
+export const CYCLE_MARKER = { [IS_CYCLE]: true as const };

 /**
 * Deeply force a value, handling cycles by returning a special marker.
@@ -160,16 +132,13 @@ export const forceDeep = (value: NixValue, seen: WeakSet<object> = new WeakSet()
  }

  if (seen.has(forced)) {
-    if (Array.isArray(forced)) {
-      return [CYCLE_MARKER];
-    }
    return CYCLE_MARKER;
  }
-  if (isAttrs(forced) || isList(forced)) {
+  if ((isAttrs(forced) && forced.size > 0) || (isList(forced) && forced.length > 0)) {
    seen.add(forced);
  }

-  if (HAS_CONTEXT in forced || IS_PATH in forced) {
+  if (forced instanceof StringWithContext || forced instanceof NixPath) {
    return forced;
  }

@@ -177,10 +146,10 @@ export const forceDeep = (value: NixValue, seen: WeakSet<object> = new WeakSet()
    return forced.map((item) => forceDeep(item, seen));
  }

-  if (typeof forced === "object") {
-    const result: Record<string, NixValue> = {};
-    for (const [key, val] of Object.entries(forced)) {
-      result[key] = forceDeep(val, seen);
+  if (forced instanceof Map) {
+    const result: NixAttrs = new Map();
+    for (const [key, val] of forced) {
+      result.set(key, forceDeep(val, seen));
    }
    return result;
  }
@@ -207,10 +176,10 @@ export const forceShallow = (value: NixValue): NixStrictValue => {
  }

  if (isAttrs(forced)) {
-    const result: Record<string, NixValue> = {};
-    for (const [key, val] of Object.entries(forced)) {
-      const forcedVal = force(val);
-      result[key] = forcedVal === forced ? CYCLE_MARKER : forcedVal;
+    const result: NixAttrs = new Map();
+    for (const [key, val] of forced) {
+      const forcedVal = force(val as NixValue);
+      result.set(key, forcedVal === forced ? CYCLE_MARKER : forcedVal);
    }
    return result;
  }
--- a/nix-js/runtime-ts/src/type-assert.ts
+++ b/nix-js/runtime-ts/src/type-assert.ts
@@ -1,27 +1,18 @@
-/**
- * Type assertion helpers for runtime type checking
- * These functions force evaluation and verify the type, throwing errors on mismatch
- */
-
+import { isAttrs, isFunction, typeOf } from "./builtins/type-check";
+import { force } from "./thunk";
 import type {
-  NixValue,
-  NixList,
  NixAttrs,
+  NixFloat,
  NixFunction,
  NixInt,
-  NixFloat,
+  NixList,
  NixNumber,
-  NixString,
  NixPath,
+  NixString,
+  NixValue,
 } from "./types";
-import { isStringWithContext, isNixPath } from "./types";
-import { force } from "./thunk";
-import { isAttrs, isFunction, typeOf } from "./builtins/type-check";
+import { isNixPath, isStringWithContext } from "./types";

-/**
- * Force a value and assert it's a list
- * @throws TypeError if value is not a list after forcing
- */
 export const forceList = (value: NixValue): NixList => {
  const forced = force(value);
  if (!Array.isArray(forced)) {
@@ -30,27 +21,19 @@ export const forceList = (value: NixValue): NixList => {
  return forced;
 };

-/**
- * Force a value and assert it's a function or functor
- * @throws TypeError if value is not a function or functor after forcing
- */
 export const forceFunction = (value: NixValue): NixFunction => {
  const forced = force(value);
  if (isFunction(forced)) {
    return forced;
  }
-  if (typeof forced === "object" && !Array.isArray(forced) && forced !== null && "__functor" in forced) {
+  if (forced instanceof Map && forced.has("__functor")) {
    const functorSet = forced as NixAttrs;
-    const functor = forceFunction(functorSet.__functor);
+    const functor = forceFunction(functorSet.get("__functor") as NixValue);
    return (arg: NixValue) => forceFunction(functor(functorSet))(arg);
  }
  throw new TypeError(`Expected function, got ${typeOf(forced)}`);
 };

-/**
- * Force a value and assert it's an attribute set
- * @throws TypeError if value is not an attribute set after forcing
- */
 export const forceAttrs = (value: NixValue): NixAttrs => {
  const forced = force(value);
  if (!isAttrs(forced)) {
@@ -59,10 +42,6 @@ export const forceAttrs = (value: NixValue): NixAttrs => {
  return forced;
 };

-/**
- * Force a value and assert it's a string (plain or with context)
- * @throws TypeError if value is not a string after forcing
- */
 export const forceStringValue = (value: NixValue): string => {
  const forced = force(value);
  if (typeof forced === "string") {
@@ -74,10 +53,6 @@ export const forceStringValue = (value: NixValue): string => {
  throw new TypeError(`Expected string, got ${typeOf(forced)}`);
 };

-/**
- * Force a value and assert it's a string, returning NixString (preserving context)
- * @throws TypeError if value is not a string after forcing
- */
 export const forceString = (value: NixValue): NixString => {
  const forced = force(value);
  if (typeof forced === "string") {
@@ -100,10 +75,6 @@ export const forceStringNoCtx = (value: NixValue): string => {
  throw new TypeError(`Expected string, got ${typeOf(forced)}`);
 };

-/**
- * Force a value and assert it's a boolean
- * @throws TypeError if value is not a boolean after forcing
- */
 export const forceBool = (value: NixValue): boolean => {
  const forced = force(value);
  if (typeof forced !== "boolean") {
@@ -112,10 +83,6 @@ export const forceBool = (value: NixValue): boolean => {
  return forced;
 };

-/**
- * Force a value and extract int value
- * @throws TypeError if value is not an int
- */
 export const forceInt = (value: NixValue): NixInt => {
  const forced = force(value);
  if (typeof forced === "bigint") {
@@ -124,10 +91,6 @@ export const forceInt = (value: NixValue): NixInt => {
  throw new TypeError(`Expected int, got ${typeOf(forced)}`);
 };

-/**
- * Force a value and extract float value
- * @throws TypeError if value is not a float
- */
 export const forceFloat = (value: NixValue): NixFloat => {
  const forced = force(value);
  if (typeof forced === "number") {
@@ -136,10 +99,6 @@ export const forceFloat = (value: NixValue): NixFloat => {
  throw new TypeError(`Expected float, got ${typeOf(forced)}`);
 };

-/**
- * Force a value and extract numeric value (int or float)
- * @throws TypeError if value is not a numeric type
- */
 export const forceNumeric = (value: NixValue): NixNumber => {
  const forced = force(value);
  if (typeof forced === "bigint" || typeof forced === "number") {
@@ -148,28 +107,17 @@ export const forceNumeric = (value: NixValue): NixNumber => {
  throw new TypeError(`Expected numeric type, got ${typeOf(forced)}`);
 };

-/**
- * Coerce two numeric values to a common type for arithmetic
- * Rule: If either is float, convert both to float; otherwise keep as bigint
- * @returns [a, b] tuple of coerced values
- */
 export const coerceNumeric = (a: NixNumber, b: NixNumber): [NixFloat, NixFloat] | [NixInt, NixInt] => {
  const aIsInt = typeof a === "bigint";
  const bIsInt = typeof b === "bigint";

-  // If either is float, convert both to float
  if (!aIsInt || !bIsInt) {
    return [Number(a), Number(b)];
  }

-  // Both are integers
  return [a, b];
 };

-/**
- * Force a value and assert it's a path
- * @throws TypeError if value is not a path after forcing
- */
 export const forceNixPath = (value: NixValue): NixPath => {
  const forced = force(value);
  if (isNixPath(forced)) {
--- a/nix-js/runtime-ts/src/types.ts
+++ b/nix-js/runtime-ts/src/types.ts
@@ -1,27 +1,24 @@
-/**
- * Core TypeScript type definitions for nix-js runtime
- */
-
-import { force, IS_THUNK } from "./thunk";
-import { type StringWithContext, HAS_CONTEXT, isStringWithContext, getStringContext } from "./string-context";
-import { op } from "./operators";
+import { PRIMOP_METADATA, type PrimopMetadata } from "./builtins";
+import { HAS_CONTEXT, isStringWithContext, type StringWithContext } from "./string-context";
+import { type CYCLE_MARKER, force, type NixThunk } from "./thunk";
 import { forceAttrs, forceStringNoCtx } from "./type-assert";
-import { isString, typeOf } from "./builtins/type-check";
 export { HAS_CONTEXT, isStringWithContext };
 export type { StringWithContext };

 export const IS_PATH = Symbol("IS_PATH");

-export interface NixPath {
-  readonly [IS_PATH]: true;
+export class NixPath {
+  readonly [IS_PATH] = true as const;
  value: string;
+  constructor(value: string) {
+    this.value = value;
+  }
 }

 export const isNixPath = (v: NixStrictValue): v is NixPath => {
-  return typeof v === "object" && v !== null && IS_PATH in v;
+  return v instanceof NixPath;
 };

-// Nix primitive types
 export type NixInt = bigint;
 export type NixFloat = number;
 export type NixNumber = NixInt | NixFloat;
@@ -29,18 +26,20 @@ export type NixBool = boolean;
 export type NixString = string | StringWithContext;
 export type NixNull = null;

-// Nix composite types
+export const ATTR_POSITIONS = Symbol("attrPositions");
 export type NixList = NixValue[];
-// FIXME: reject contextful string
-export type NixAttrs = { [key: string]: NixValue };
-export type NixFunction = ((arg: NixValue) => NixValue) & { args?: NixArgs };
+export type NixAttrs = Map<string, NixValue> & { [ATTR_POSITIONS]?: Map<string, number> };
+export type NixFunction = ((arg: NixValue) => NixValue) & {
+  args?: NixArgs;
+  [PRIMOP_METADATA]?: PrimopMetadata;
+};
 export class NixArgs {
  required: string[];
  optional: string[];
  allowed: Set<string>;
  ellipsis: boolean;
-  positions: Record<string, string>;
-  constructor(required: string[], optional: string[], positions: Record<string, string>, ellipsis: boolean) {
+  positions: Map<string, number>;
+  constructor(required: string[], optional: string[], positions: Map<string, number>, ellipsis: boolean) {
    this.required = required;
    this.optional = optional;
    this.positions = positions;
@@ -51,13 +50,13 @@ export class NixArgs {
    const attrs = forceAttrs(arg);

    for (const key of this.required) {
-      if (!Object.hasOwn(attrs, key)) {
+      if (!attrs.has(key)) {
        throw new Error(`Function called without required argument '${key}'`);
      }
    }

    if (!this.ellipsis) {
-      for (const key in attrs) {
+      for (const key of attrs.keys()) {
        if (!this.allowed.has(key)) {
          throw new Error(`Function called with unexpected argument '${key}'`);
        }
@@ -69,33 +68,18 @@ export const mkFunction = (
  f: (arg: NixValue) => NixValue,
  required: string[],
  optional: string[],
-  positions: Record<string, string>,
+  positions: Map<string, number>,
  ellipsis: boolean,
 ): NixFunction => {
-  const func = f as NixFunction;
+  const func: NixFunction = f;
  func.args = new NixArgs(required, optional, positions, ellipsis);
  return func;
 };

-export const mkAttrs = (attrs: NixAttrs, keys: NixValue[], values: NixValue[]): NixAttrs => {
-  const len = keys.length;
-  for (let i = 0; i < len; i++) {
-    const key = force(keys[i]);
-    if (key === null) {
-      continue;
-    }
-    const str = forceStringNoCtx(key);
-    attrs[str] = values[i];
-  }
-  return attrs;
-};
-
-const ATTR_POSITIONS = Symbol("attrPositions");
-
-export const mkAttrsWithPos = (
+export const mkAttrs = (
  attrs: NixAttrs,
-  positions: Record<string, string>,
-  dyns?: { dynKeys: NixValue[]; dynVals: NixValue[]; dynSpans: string[] },
+  positions: Map<string, number>,
+  dyns?: { dynKeys: NixValue[]; dynVals: NixValue[]; dynSpans: number[] },
 ): NixAttrs => {
  if (dyns) {
    const len = dyns.dynKeys.length;
@@ -105,62 +89,27 @@ export const mkAttrsWithPos = (
        continue;
      }
      const str = forceStringNoCtx(key);
-      attrs[str] = dyns.dynVals[i];
-      positions[str] = dyns.dynSpans[i];
+      attrs.set(str, dyns.dynVals[i]);
+      positions.set(str, dyns.dynSpans[i]);
    }
  }

-  if (Object.keys(positions).length > 0) {
-    Object.defineProperty(attrs, ATTR_POSITIONS, {
-      value: positions,
-      enumerable: false,
-      writable: false,
-    });
+  if (positions.size > 0) {
+    attrs[ATTR_POSITIONS] = positions;
  }

  return attrs;
 };

-export { ATTR_POSITIONS };
-
-/**
- * Interface for lazy thunk values
- * Thunks delay evaluation until forced
- */
-export interface NixThunkInterface {
-  readonly [IS_THUNK]: true;
-  func: (() => NixValue) | undefined;
-  result: NixStrictValue | undefined;
-}
-
-// Union of all Nix primitive types
 export type NixPrimitive = NixNull | NixBool | NixInt | NixFloat | NixString;
+export type NixValue =
+  | NixPrimitive
+  | NixPath
+  | NixList
+  | NixAttrs
+  | NixFunction
+  | NixThunk
+  | typeof CYCLE_MARKER;
+export type NixStrictValue = Exclude<NixValue, NixThunk>;

-/**
- * NixValue: Union type representing any possible Nix value
- * This is the core type used throughout the runtime
- */
-export type NixValue = NixPrimitive | NixPath | NixList | NixAttrs | NixFunction | NixThunkInterface;
-
-export type NixStrictValue = Exclude<NixValue, NixThunkInterface>;
-
-/**
- * CatchableError: Error type thrown by `builtins.throw`
- * This can be caught by `builtins.tryEval`
- */
 export class CatchableError extends Error {}
-
-// Operator function signatures
-export type BinaryOp<T = NixValue, U = NixValue, R = NixValue> = (a: T, b: U) => R;
-export type UnaryOp<T = NixValue, R = NixValue> = (a: T) => R;
-
-/**
- * Curried function types - All Nix builtins must be curried!
- *
- * Examples:
- * - add: Curried2<number, number, number> = (a) => (b) => a + b
- * - map: Curried2<NixFunction, NixList, NixList> = (f) => (list) => list.map(f)
- */
-export type Curried2<A, B, R> = (a: A) => (b: B) => R;
-export type Curried3<A, B, C, R> = (a: A) => (b: B) => (c: C) => R;
-export type Curried4<A, B, C, D, R> = (a: A) => (b: B) => (c: C) => (d: D) => R;
--- a/nix-js/runtime-ts/src/types/global.d.ts
+++ b/nix-js/runtime-ts/src/types/global.d.ts
@@ -1,36 +1,116 @@
 import type { NixRuntime } from "..";
-import type { FetchTarballResult, FetchUrlResult, FetchGitResult, FetchHgResult } from "../builtins/io";
+import type { builtins } from "../builtins";
+import type { FetchGitResult, FetchTarballResult, FetchUrlResult } from "../builtins/io";
+import type {
+  assert,
+  call,
+  concatStringsWithContext,
+  hasAttr,
+  lookupWith,
+  mkPos,
+  resolvePath,
+  select,
+  selectWithDefault,
+} from "../helpers";
+import type { op } from "../operators";
+import type { createThunk, force } from "../thunk";
+import type { forceBool } from "../type-assert";
+import type { mkAttrs, mkFunction, NixAttrs, NixStrictValue } from "../types";

 declare global {
  var Nix: NixRuntime;
+  var $t: typeof createThunk;
+  var $f: typeof force;
+  var $fb: typeof forceBool;
+  var $a: typeof assert;
+  var $c: typeof call;
+  var $h: typeof hasAttr;
+  var $s: typeof select;
+  var $sd: typeof selectWithDefault;
+  var $l: typeof lookupWith;
+  var $r: typeof resolvePath;
+  var $cs: typeof concatStringsWithContext;
+  var $ma: typeof mkAttrs;
+  var $mf: typeof mkFunction;
+  var $mp: typeof mkPos;
+  var $oa: typeof op.add;
+  var $os: typeof op.sub;
+  var $om: typeof op.mul;
+  var $od: typeof op.div;
+  var $oe: typeof op.eq;
+  var $ol: typeof op.lt;
+  var $og: typeof op.gt;
+  var $oc: typeof op.concat;
+  var $ou: typeof op.update;
+  var $b: typeof builtins;
+  var $e: NixAttrs;
+  var $gb: typeof Nix.getReplBinding;
+
  namespace Deno {
    namespace core {
      namespace ops {
+        function op_import(path: string): [Uint8Array, string];
+        function op_scoped_import(path: string, scopeKeys: string[]): [Uint8Array, string];
+
        function op_resolve_path(currentDir: string, path: string): string;
-        function op_import(path: string): string;
-        function op_scoped_import(path: string, scopeKeys: string[]): string;
+
        function op_read_file(path: string): string;
        function op_read_file_type(path: string): string;
-        function op_read_dir(path: string): Record<string, string>;
+        function op_read_dir(path: string): Map<string, string>;
        function op_path_exists(path: string): boolean;
-        function op_sha256_hex(data: string): string;
+        function op_walk_dir(path: string): [string, string][];
+
        function op_make_placeholder(output: string): string;
-        function op_decode_span(span: string): {
-          file: string | null;
-          line: number | null;
-          column: number | null;
-        };
-        function op_make_store_path(ty: string, hash_hex: string, name: string): string;
-        function op_parse_hash(hash_str: string, algo: string | null): { hex: string; algo: string };
-        function op_make_fixed_output_path(
-          hash_algo: string,
-          hash: string,
-          hash_mode: string,
-          name: string,
+        function op_store_path(path: string): string;
+
+        function op_convert_hash(hash: string, hashAlgo: string | null, toHashFormat: string): string;
+        function op_hash_string(algo: string, data: string): string;
+        function op_hash_file(algo: string, path: string): string;
+        function op_parse_hash(hashStr: string, algo: string | null): { hex: string; algo: string };
+
+        function op_add_path(
+          path: string,
+          name: string | null,
+          recursive: boolean,
+          sha256: string | null,
        ): string;
+        function op_add_filtered_path(
+          path: string,
+          name: string | null,
+          recursive: boolean,
+          sha256: string | null,
+          includePaths: string[],
+        ): string;
+
+        function op_decode_span(span: number): NixAttrs;
+
+        function op_to_file(name: string, contents: string, references: string[]): string;
+
+        function op_copy_path_to_store(path: string): string;
+
+        function op_get_env(key: string): string;
+
+        function op_match(regex: string, text: string): (string | null)[] | null;
+        function op_split(regex: string, text: string): (string | (string | null)[])[];
+
+        function op_from_json(json: string): NixStrictValue;
+        function op_from_toml(toml: string): NixStrictValue;
+        function op_to_xml(e: NixValue): [string, string[]];
+
+        function op_finalize_derivation(
+          name: string,
+          builder: string,
+          platform: string,
+          outputs: string[],
+          args: string[],
+          env: [string, string][],
+          context: string[],
+          fixedOutput: { hashAlgo: string; hash: string; hashMode: string } | null,
+        ): { drvPath: string; outputs: [string, string][] };
+
        function op_fetch_url(
          url: string,
-          expected_hash: string | null,
+          expectedHash: string | null,
          name: string | null,
          executable: boolean,
        ): FetchUrlResult;
@@ -45,37 +125,9 @@ declare global {
          rev: string | null,
          shallow: boolean,
          submodules: boolean,
-          all_refs: boolean,
+          allRefs: boolean,
          name: string | null,
        ): FetchGitResult;
-        function op_add_path(
-          path: string,
-          name: string | null,
-          recursive: boolean,
-          sha256: string | null,
-        ): string;
-        function op_store_path(path: string): string;
-        function op_to_file(name: string, contents: string, references: string[]): string;
-        function op_write_derivation(drv_name: string, aterm: string, references: string[]): string;
-        function op_read_derivation_outputs(drv_path: string): string[];
-        function op_compute_fs_closure(drv_path: string): {
-          input_drvs: [string, string[]][];
-          input_srcs: string[];
-        };
-        function op_copy_path_to_store(path: string): string;
-        function op_get_env(key: string): string;
-        function op_walk_dir(path: string): [string, string][];
-        function op_add_filtered_path(
-          path: string,
-          name: string | null,
-          recursive: boolean,
-          sha256: string | null,
-          include_paths: string[],
-        ): string;
-        function op_match(regex: string, text: string): (string | null)[] | null;
-        function op_split(regex: string, text: string): (string | (string | null)[])[];
-        function op_from_json(json: string): any;
-        function op_from_toml(toml: string): any;
      }
    }
  }
--- a/nix-js/runtime-ts/src/vm.ts
+++ b/nix-js/runtime-ts/src/vm.ts
@@ -0,0 +1,617 @@
+import {
+  assert,
+  call,
+  concatStringsWithContext,
+  hasAttr,
+  lookupWith,
+  mkPos,
+  resolvePath,
+  select,
+  selectWithDefault,
+} from "./helpers";
+import { op } from "./operators";
+import { NixThunk } from "./thunk";
+import { forceBool } from "./type-assert";
+import { mkAttrs, NixArgs, type NixAttrs, type NixFunction, type NixValue } from "./types";
+import { builtins } from "./builtins";
+
+enum Op {
+  PushConst = 0x01,
+  PushString = 0x02,
+  PushNull = 0x03,
+  PushTrue = 0x04,
+  PushFalse = 0x05,
+
+  LoadLocal = 0x06,
+  LoadOuter = 0x07,
+  StoreLocal = 0x08,
+  AllocLocals = 0x09,
+
+  MakeThunk = 0x0A,
+  MakeClosure = 0x0B,
+  MakePatternClosure = 0x0C,
+
+  Call = 0x0D,
+  CallNoSpan = 0x0E,
+
+  MakeAttrs = 0x0F,
+  MakeAttrsDyn = 0x10,
+  MakeEmptyAttrs = 0x11,
+  Select = 0x12,
+  SelectDefault = 0x13,
+  HasAttr = 0x14,
+
+  MakeList = 0x15,
+
+  OpAdd = 0x16,
+  OpSub = 0x17,
+  OpMul = 0x18,
+  OpDiv = 0x19,
+  OpEq = 0x20,
+  OpNeq = 0x21,
+  OpLt = 0x22,
+  OpGt = 0x23,
+  OpLeq = 0x24,
+  OpGeq = 0x25,
+  OpConcat = 0x26,
+  OpUpdate = 0x27,
+
+  OpNeg = 0x28,
+  OpNot = 0x29,
+
+  ForceBool = 0x30,
+  JumpIfFalse = 0x31,
+  JumpIfTrue = 0x32,
+  Jump = 0x33,
+
+  ConcatStrings = 0x34,
+  ResolvePath = 0x35,
+
+  Assert = 0x36,
+
+  PushWith = 0x37,
+  PopWith = 0x38,
+  WithLookup = 0x39,
+
+  LoadBuiltins = 0x40,
+  LoadBuiltin = 0x41,
+
+  MkPos = 0x43,
+
+  LoadReplBinding = 0x44,
+  LoadScopedBinding = 0x45,
+
+  Return = 0x46,
+}
+
+interface ScopeChain {
+  locals: NixValue[];
+  parent: ScopeChain | null;
+}
+
+interface WithScope {
+  env: NixValue;
+  last: WithScope | null;
+}
+
+const strings: string[] = [];
+const constants: NixValue[] = [];
+
+const $e: NixAttrs = new Map();
+
+function readU16(code: Uint8Array, offset: number): number {
+  return code[offset] | (code[offset + 1] << 8);
+}
+
+function readU32(code: Uint8Array, offset: number): number {
+  return (
+    code[offset] |
+    (code[offset + 1] << 8) |
+    (code[offset + 2] << 16) |
+    (code[offset + 3] << 24)
+  ) >>> 0;
+}
+
+function readI32(code: Uint8Array, offset: number): number {
+  return code[offset] | (code[offset + 1] << 8) | (code[offset + 2] << 16) | (code[offset + 3] << 24);
+}
+
+export function execBytecode(code: Uint8Array, currentDir: string): NixValue {
+  const chain: ScopeChain = { locals: [], parent: null };
+  return execFrame(code, 0, chain, currentDir, null, null);
+}
+
+export function execBytecodeScoped(
+  code: Uint8Array,
+  currentDir: string,
+  scopeMap: NixAttrs,
+): NixValue {
+  const chain: ScopeChain = { locals: [], parent: null };
+  return execFrame(code, 0, chain, currentDir, null, scopeMap);
+}
+
+function execFrame(
+  code: Uint8Array,
+  startPc: number,
+  chain: ScopeChain,
+  currentDir: string,
+  withScope: WithScope | null,
+  scopeMap: NixAttrs | null,
+): NixValue {
+  const locals = chain.locals;
+  const stack: NixValue[] = [];
+  let pc = startPc;
+
+  for (;;) {
+    const opcode = code[pc++];
+    switch (opcode) {
+      case Op.PushConst: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        stack.push(constants[idx]);
+        break;
+      }
+      case Op.PushString: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        stack.push(strings[idx]);
+        break;
+      }
+      case Op.PushNull:
+        stack.push(null);
+        break;
+      case Op.PushTrue:
+        stack.push(true);
+        break;
+      case Op.PushFalse:
+        stack.push(false);
+        break;
+
+      case Op.LoadLocal: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        stack.push(locals[idx]);
+        break;
+      }
+      case Op.LoadOuter: {
+        const layer = code[pc++];
+        const idx = readU32(code, pc);
+        pc += 4;
+        let c: ScopeChain = chain;
+        for (let i = 0; i < layer; i++) c = c.parent!;
+        stack.push(c.locals[idx]);
+        break;
+      }
+      case Op.StoreLocal: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        locals[idx] = stack.pop()!;
+        break;
+      }
+      case Op.AllocLocals: {
+        const n = readU32(code, pc);
+        pc += 4;
+        for (let i = 0; i < n; i++) locals.push(null);
+        break;
+      }
+
+      case Op.MakeThunk: {
+        const bodyPc = readU32(code, pc);
+        pc += 4;
+        const labelIdx = readU32(code, pc);
+        pc += 4;
+        const label = strings[labelIdx];
+        const scopeChain = chain;
+        const scopeCode = code;
+        const scopeDir = currentDir;
+        const scopeWith = withScope;
+        stack.push(
+          new NixThunk(
+            () => execFrame(scopeCode, bodyPc, scopeChain, scopeDir, scopeWith, null),
+            label,
+          ),
+        );
+        break;
+      }
+      case Op.MakeClosure: {
+        const bodyPc = readU32(code, pc);
+        pc += 4;
+        const nSlots = readU32(code, pc);
+        pc += 4;
+        const closureChain = chain;
+        const closureCode = code;
+        const closureDir = currentDir;
+        const closureWith = withScope;
+        const func: NixFunction = (arg: NixValue) => {
+          const innerLocals = new Array<NixValue>(1 + nSlots).fill(null);
+          innerLocals[0] = arg;
+          const innerChain: ScopeChain = { locals: innerLocals, parent: closureChain };
+          return execFrame(closureCode, bodyPc, innerChain, closureDir, closureWith, null);
+        };
+        stack.push(func);
+        break;
+      }
+      case Op.MakePatternClosure: {
+        const bodyPc = readU32(code, pc);
+        pc += 4;
+        const nSlots = readU32(code, pc);
+        pc += 4;
+        const nRequired = readU16(code, pc);
+        pc += 2;
+        const nOptional = readU16(code, pc);
+        pc += 2;
+        const hasEllipsis = code[pc++] !== 0;
+
+        const required: string[] = [];
+        for (let i = 0; i < nRequired; i++) {
+          required.push(strings[readU32(code, pc)]);
+          pc += 4;
+        }
+        const optional: string[] = [];
+        for (let i = 0; i < nOptional; i++) {
+          optional.push(strings[readU32(code, pc)]);
+          pc += 4;
+        }
+        const positions = new Map<string, number>();
+        const nTotal = nRequired + nOptional;
+        for (let i = 0; i < nTotal; i++) {
+          const nameIdx = readU32(code, pc);
+          pc += 4;
+          const spanId = readU32(code, pc);
+          pc += 4;
+          positions.set(strings[nameIdx], spanId);
+        }
+
+        const closureChain = chain;
+        const closureCode = code;
+        const closureDir = currentDir;
+        const closureWith = withScope;
+        const func: NixFunction = (arg: NixValue) => {
+          const innerLocals = new Array<NixValue>(1 + nSlots).fill(null);
+          innerLocals[0] = arg;
+          const innerChain: ScopeChain = { locals: innerLocals, parent: closureChain };
+          return execFrame(closureCode, bodyPc, innerChain, closureDir, closureWith, null);
+        };
+        func.args = new NixArgs(required, optional, positions, hasEllipsis);
+        stack.push(func);
+        break;
+      }
+
+      case Op.Call: {
+        const spanId = readU32(code, pc);
+        pc += 4;
+        const arg = stack.pop()!;
+        const func = stack.pop()!;
+        stack.push(call(func, arg, spanId));
+        break;
+      }
+      case Op.CallNoSpan: {
+        const arg = stack.pop()!;
+        const func = stack.pop()!;
+        stack.push(call(func, arg));
+        break;
+      }
+
+      case Op.MakeAttrs: {
+        const n = readU32(code, pc);
+        pc += 4;
+        const spanValues: number[] = [];
+        for (let i = 0; i < n; i++) {
+          spanValues.push(stack.pop() as number);
+        }
+        spanValues.reverse();
+        const map: NixAttrs = new Map();
+        const posMap = new Map<string, number>();
+        const pairs: [string, NixValue][] = [];
+        for (let i = 0; i < n; i++) {
+          const val = stack.pop()!;
+          const key = stack.pop() as string;
+          pairs.push([key, val]);
+        }
+        pairs.reverse();
+        for (let i = 0; i < n; i++) {
+          map.set(pairs[i][0], pairs[i][1]);
+          posMap.set(pairs[i][0], spanValues[i]);
+        }
+        stack.push(mkAttrs(map, posMap));
+        break;
+      }
+      case Op.MakeAttrsDyn: {
+        const nStatic = readU32(code, pc);
+        pc += 4;
+        const nDyn = readU32(code, pc);
+        pc += 4;
+
+        const dynTriples: [NixValue, NixValue, number][] = [];
+        for (let i = 0; i < nDyn; i++) {
+          const dynSpan = stack.pop() as number;
+          const dynVal = stack.pop()!;
+          const dynKey = stack.pop()!;
+          dynTriples.push([dynKey, dynVal, dynSpan]);
+        }
+        dynTriples.reverse();
+
+        const spanValues: number[] = [];
+        for (let i = 0; i < nStatic; i++) {
+          spanValues.push(stack.pop() as number);
+        }
+        spanValues.reverse();
+
+        const map: NixAttrs = new Map();
+        const posMap = new Map<string, number>();
+        const pairs: [string, NixValue][] = [];
+        for (let i = 0; i < nStatic; i++) {
+          const val = stack.pop()!;
+          const key = stack.pop() as string;
+          pairs.push([key, val]);
+        }
+        pairs.reverse();
+        for (let i = 0; i < nStatic; i++) {
+          map.set(pairs[i][0], pairs[i][1]);
+          posMap.set(pairs[i][0], spanValues[i]);
+        }
+
+        const dynKeys: NixValue[] = [];
+        const dynVals: NixValue[] = [];
+        const dynSpans: number[] = [];
+        for (const [k, v, s] of dynTriples) {
+          dynKeys.push(k);
+          dynVals.push(v);
+          dynSpans.push(s);
+        }
+
+        stack.push(mkAttrs(map, posMap, { dynKeys, dynVals, dynSpans }));
+        break;
+      }
+      case Op.MakeEmptyAttrs:
+        stack.push($e);
+        break;
+
+      case Op.Select: {
+        const nKeys = readU16(code, pc);
+        pc += 2;
+        const spanId = readU32(code, pc);
+        pc += 4;
+        const keys: NixValue[] = [];
+        for (let i = 0; i < nKeys; i++) keys.push(stack.pop()!);
+        keys.reverse();
+        const obj = stack.pop()!;
+        stack.push(select(obj, keys, spanId));
+        break;
+      }
+      case Op.SelectDefault: {
+        const nKeys = readU16(code, pc);
+        pc += 2;
+        const spanId = readU32(code, pc);
+        pc += 4;
+        const defaultVal = stack.pop()!;
+        const keys: NixValue[] = [];
+        for (let i = 0; i < nKeys; i++) keys.push(stack.pop()!);
+        keys.reverse();
+        const obj = stack.pop()!;
+        stack.push(selectWithDefault(obj, keys, defaultVal, spanId));
+        break;
+      }
+      case Op.HasAttr: {
+        const nKeys = readU16(code, pc);
+        pc += 2;
+        const keys: NixValue[] = [];
+        for (let i = 0; i < nKeys; i++) keys.push(stack.pop()!);
+        keys.reverse();
+        const obj = stack.pop()!;
+        stack.push(hasAttr(obj, keys));
+        break;
+      }
+
+      case Op.MakeList: {
+        const count = readU32(code, pc);
+        pc += 4;
+        const items: NixValue[] = new Array(count);
+        for (let i = count - 1; i >= 0; i--) {
+          items[i] = stack.pop()!;
+        }
+        stack.push(items);
+        break;
+      }
+
+      case Op.OpAdd: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.add(a, b));
+        break;
+      }
+      case Op.OpSub: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.sub(a, b));
+        break;
+      }
+      case Op.OpMul: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.mul(a, b));
+        break;
+      }
+      case Op.OpDiv: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.div(a, b));
+        break;
+      }
+      case Op.OpEq: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.eq(a, b));
+        break;
+      }
+      case Op.OpNeq: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(!op.eq(a, b));
+        break;
+      }
+      case Op.OpLt: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.lt(a, b));
+        break;
+      }
+      case Op.OpGt: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.gt(a, b));
+        break;
+      }
+      case Op.OpLeq: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(!op.gt(a, b));
+        break;
+      }
+      case Op.OpGeq: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(!op.lt(a, b));
+        break;
+      }
+      case Op.OpConcat: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.concat(a, b));
+        break;
+      }
+      case Op.OpUpdate: {
+        const b = stack.pop()!;
+        const a = stack.pop()!;
+        stack.push(op.update(a, b));
+        break;
+      }
+
+      case Op.OpNeg: {
+        const a = stack.pop()!;
+        stack.push(op.sub(0n, a));
+        break;
+      }
+      case Op.OpNot: {
+        const a = stack.pop()!;
+        stack.push(!forceBool(a));
+        break;
+      }
+
+      case Op.ForceBool: {
+        const val = stack.pop()!;
+        stack.push(forceBool(val));
+        break;
+      }
+      case Op.JumpIfFalse: {
+        const offset = readI32(code, pc);
+        pc += 4;
+        const val = stack.pop()!;
+        if (val === false) {
+          pc += offset;
+        }
+        break;
+      }
+      case Op.JumpIfTrue: {
+        const offset = readI32(code, pc);
+        pc += 4;
+        const val = stack.pop()!;
+        if (val === true) {
+          pc += offset;
+        }
+        break;
+      }
+      case Op.Jump: {
+        const offset = readI32(code, pc);
+        pc += 4;
+        pc += offset;
+        break;
+      }
+
+      case Op.ConcatStrings: {
+        const nParts = readU16(code, pc);
+        pc += 2;
+        const forceString = code[pc++] !== 0;
+        const parts: NixValue[] = new Array(nParts);
+        for (let i = nParts - 1; i >= 0; i--) {
+          parts[i] = stack.pop()!;
+        }
+        stack.push(concatStringsWithContext(parts, forceString));
+        break;
+      }
+      case Op.ResolvePath: {
+        const pathExpr = stack.pop()!;
+        stack.push(resolvePath(currentDir, pathExpr));
+        break;
+      }
+
+      case Op.Assert: {
+        const rawIdx = readU32(code, pc);
+        pc += 4;
+        const spanId = readU32(code, pc);
+        pc += 4;
+        const expr = stack.pop()!;
+        const assertion = stack.pop()!;
+        stack.push(assert(assertion, expr, strings[rawIdx], spanId));
+        break;
+      }
+
+      case Op.PushWith: {
+        const namespace = stack.pop()!;
+        withScope = { env: namespace, last: withScope };
+        break;
+      }
+      case Op.PopWith:
+        withScope = withScope!.last;
+        break;
+      case Op.WithLookup: {
+        const nameIdx = readU32(code, pc);
+        pc += 4;
+        stack.push(lookupWith(strings[nameIdx], withScope!));
+        break;
+      }
+
+      case Op.LoadBuiltins:
+        stack.push(builtins);
+        break;
+      case Op.LoadBuiltin: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        stack.push(builtins.get(strings[idx])!);
+        break;
+      }
+
+      case Op.MkPos: {
+        const spanId = readU32(code, pc);
+        pc += 4;
+        stack.push(mkPos(spanId));
+        break;
+      }
+
+      case Op.LoadReplBinding: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        stack.push(Nix.getReplBinding(strings[idx]));
+        break;
+      }
+      case Op.LoadScopedBinding: {
+        const idx = readU32(code, pc);
+        pc += 4;
+        stack.push(scopeMap!.get(strings[idx])!);
+        break;
+      }
+
+      case Op.Return:
+        return stack.pop()!;
+
+      default:
+        throw new Error(`Unknown bytecode opcode: ${opcode ? `0x${opcode.toString(16)}` : "undefined"} at pc=${pc - 1}`);
+    }
+  }
+}
+
+declare const Nix: {
+  getReplBinding: (name: string) => NixValue;
+};
+
+export { strings as vmStrings, constants as vmConstants };
--- a/nix-js/src/bin/eval.rs
+++ b/nix-js/src/bin/eval.rs
@@ -1,26 +0,0 @@
-use anyhow::Result;
-use nix_js::{context::Context, error::Source};
-use std::process::exit;
-
-fn main() -> Result<()> {
-    nix_js::logging::init_logging();
-
-    let mut args = std::env::args();
-    if args.len() != 2 {
-        eprintln!("Usage: {} expr", args.next().unwrap());
-        exit(1);
-    }
-    args.next();
-    let expr = args.next().unwrap();
-    let src = Source::new_eval(expr)?;
-    match Context::new()?.eval(src) {
-        Ok(value) => {
-            println!("{value}");
-            Ok(())
-        }
-        Err(err) => {
-            eprintln!("{:?}", miette::Report::new(*err));
-            exit(1);
-        }
-    }
-}
--- a/nix-js/src/bin/repl.rs
+++ b/nix-js/src/bin/repl.rs
@@ -1,63 +0,0 @@
-use anyhow::Result;
-use hashbrown::HashSet;
-use nix_js::context::Context;
-use nix_js::error::Source;
-use rustyline::DefaultEditor;
-use rustyline::error::ReadlineError;
-
-fn main() -> Result<()> {
-    nix_js::logging::init_logging();
-
-    let mut rl = DefaultEditor::new()?;
-    let mut context = Context::new()?;
-    let mut scope = HashSet::new();
-    const RE: ere::Regex<3> = ere::compile_regex!("^[ \t]*([a-zA-Z_][a-zA-Z0-9_'-]*)[ \t]*(.*)$");
-    loop {
-        let readline = rl.readline("nix-js-repl> ");
-        match readline {
-            Ok(line) => {
-                if line.trim().is_empty() {
-                    continue;
-                }
-                let _ = rl.add_history_entry(line.as_str());
-                if let Some([Some(_), Some(ident), Some(rest)]) = RE.exec(&line) {
-                    if let Some(expr) = rest.strip_prefix('=') {
-                        let expr = expr.trim_start();
-                        if expr.is_empty() {
-                            eprintln!("Error: missing expression after '='");
-                            continue;
-                        }
-                        match context.add_binding(ident, expr, &mut scope) {
-                            Ok(value) => println!("{} = {}", ident, value),
-                            Err(err) => eprintln!("{:?}", miette::Report::new(*err)),
-                        }
-                    } else {
-                        let src = Source::new_repl(line)?;
-                        match context.eval_repl(src, &scope) {
-                            Ok(value) => println!("{value}"),
-                            Err(err) => eprintln!("{:?}", miette::Report::new(*err)),
-                        }
-                    }
-                } else {
-                    let src = Source::new_repl(line)?;
-                    match context.eval_shallow(src) {
-                        Ok(value) => println!("{value}"),
-                        Err(err) => eprintln!("{:?}", miette::Report::new(*err)),
-                    }
-                }
-            }
-            Err(ReadlineError::Interrupted) => {
-                println!();
-            }
-            Err(ReadlineError::Eof) => {
-                println!("CTRL-D");
-                break;
-            }
-            Err(err) => {
-                eprintln!("Error: {err:?}");
-                break;
-            }
-        }
-    }
-    Ok(())
-}
--- a/nix-js/src/bytecode.rs
+++ b/nix-js/src/bytecode.rs
@@ -0,0 +1,906 @@
+use std::ops::Deref;
+use std::path::Path;
+
+use hashbrown::HashMap;
+use num_enum::TryFromPrimitive;
+use rnix::TextRange;
+
+use crate::ir::{ArgId, Attr, BinOpKind, Ir, Param, RawIrRef, SymId, ThunkId, UnOpKind};
+
+#[derive(Clone, Hash, Eq, PartialEq)]
+pub(crate) enum Constant {
+    Int(i64),
+    Float(u64),
+}
+
+pub struct Bytecode {
+    pub code: Box<[u8]>,
+    pub current_dir: String,
+}
+
+pub(crate) trait BytecodeContext {
+    fn intern_string(&mut self, s: &str) -> u32;
+    fn intern_constant(&mut self, c: Constant) -> u32;
+    fn register_span(&self, range: TextRange) -> u32;
+    fn get_sym(&self, id: SymId) -> &str;
+    fn get_current_dir(&self) -> &Path;
+}
+
+#[repr(u8)]
+#[derive(Clone, Copy, TryFromPrimitive)]
+#[allow(clippy::enum_variant_names)]
+pub enum Op {
+    PushConst = 0x01,
+    PushString = 0x02,
+    PushNull = 0x03,
+    PushTrue = 0x04,
+    PushFalse = 0x05,
+
+    LoadLocal = 0x06,
+    LoadOuter = 0x07,
+    StoreLocal = 0x08,
+    AllocLocals = 0x09,
+
+    MakeThunk = 0x0A,
+    MakeClosure = 0x0B,
+    MakePatternClosure = 0x0C,
+
+    Call = 0x0D,
+    CallNoSpan = 0x0E,
+
+    MakeAttrs = 0x0F,
+    MakeAttrsDyn = 0x10,
+    MakeEmptyAttrs = 0x11,
+    Select = 0x12,
+    SelectDefault = 0x13,
+    HasAttr = 0x14,
+
+    MakeList = 0x15,
+
+    OpAdd = 0x16,
+    OpSub = 0x17,
+    OpMul = 0x18,
+    OpDiv = 0x19,
+    OpEq = 0x20,
+    OpNeq = 0x21,
+    OpLt = 0x22,
+    OpGt = 0x23,
+    OpLeq = 0x24,
+    OpGeq = 0x25,
+    OpConcat = 0x26,
+    OpUpdate = 0x27,
+
+    OpNeg = 0x28,
+    OpNot = 0x29,
+
+    ForceBool = 0x30,
+    JumpIfFalse = 0x31,
+    JumpIfTrue = 0x32,
+    Jump = 0x33,
+
+    ConcatStrings = 0x34,
+    ResolvePath = 0x35,
+
+    Assert = 0x36,
+
+    PushWith = 0x37,
+    PopWith = 0x38,
+    WithLookup = 0x39,
+
+    LoadBuiltins = 0x40,
+    LoadBuiltin = 0x41,
+
+    MkPos = 0x43,
+
+    LoadReplBinding = 0x44,
+    LoadScopedBinding = 0x45,
+
+    Return = 0x46,
+}
+
+struct ScopeInfo {
+    depth: u16,
+    arg_id: Option<ArgId>,
+    thunk_map: HashMap<ThunkId, u32>,
+}
+
+struct BytecodeEmitter<'a, Ctx: BytecodeContext> {
+    ctx: &'a mut Ctx,
+    code: Vec<u8>,
+    scope_stack: Vec<ScopeInfo>,
+}
+
+pub(crate) fn compile_bytecode(ir: RawIrRef<'_>, ctx: &mut impl BytecodeContext) -> Bytecode {
+    let current_dir = ctx.get_current_dir().to_string_lossy().to_string();
+    let mut emitter = BytecodeEmitter::new(ctx);
+    emitter.emit_toplevel(ir);
+    Bytecode {
+        code: emitter.code.into_boxed_slice(),
+        current_dir,
+    }
+}
+
+pub(crate) fn compile_bytecode_scoped(
+    ir: RawIrRef<'_>,
+    ctx: &mut impl BytecodeContext,
+) -> Bytecode {
+    let current_dir = ctx.get_current_dir().to_string_lossy().to_string();
+    let mut emitter = BytecodeEmitter::new(ctx);
+    emitter.emit_toplevel_scoped(ir);
+    Bytecode {
+        code: emitter.code.into_boxed_slice(),
+        current_dir,
+    }
+}
+
+impl<'a, Ctx: BytecodeContext> BytecodeEmitter<'a, Ctx> {
+    fn new(ctx: &'a mut Ctx) -> Self {
+        Self {
+            ctx,
+            code: Vec::with_capacity(4096),
+            scope_stack: Vec::with_capacity(32),
+        }
+    }
+
+    #[inline]
+    fn emit_op(&mut self, op: Op) {
+        self.code.push(op as u8);
+    }
+
+    #[inline]
+    fn emit_u8(&mut self, val: u8) {
+        self.code.push(val);
+    }
+
+    #[inline]
+    fn emit_u16(&mut self, val: u16) {
+        self.code.extend_from_slice(&val.to_le_bytes());
+    }
+
+    #[inline]
+    fn emit_u32(&mut self, val: u32) {
+        self.code.extend_from_slice(&val.to_le_bytes());
+    }
+
+    #[inline]
+    fn emit_i32_placeholder(&mut self) -> usize {
+        let offset = self.code.len();
+        self.code.extend_from_slice(&[0u8; 4]);
+        offset
+    }
+    #[inline]
+    fn patch_i32(&mut self, offset: usize, val: i32) {
+        self.code[offset..offset + 4].copy_from_slice(&val.to_le_bytes());
+    }
+
+    #[inline]
+    fn emit_jump_placeholder(&mut self) -> usize {
+        self.emit_op(Op::Jump);
+        self.emit_i32_placeholder()
+    }
+
+    #[inline]
+    fn patch_jump_target(&mut self, placeholder_offset: usize) {
+        let current_pos = self.code.len();
+        let relative_offset = (current_pos as i32) - (placeholder_offset as i32) - 4;
+        self.patch_i32(placeholder_offset, relative_offset);
+    }
+
+    fn current_depth(&self) -> u16 {
+        self.scope_stack.last().map_or(0, |s| s.depth)
+    }
+
+    fn resolve_thunk(&self, id: ThunkId) -> (u16, u32) {
+        for scope in self.scope_stack.iter().rev() {
+            if let Some(&local_idx) = scope.thunk_map.get(&id) {
+                let layer = self.current_depth() - scope.depth;
+                return (layer, local_idx);
+            }
+        }
+        panic!("ThunkId {:?} not found in any scope", id);
+    }
+
+    fn resolve_arg(&self, id: ArgId) -> (u16, u32) {
+        for scope in self.scope_stack.iter().rev() {
+            if scope.arg_id == Some(id) {
+                let layer = self.current_depth() - scope.depth;
+                return (layer, 0);
+            }
+        }
+        panic!("ArgId {:?} not found in any scope", id);
+    }
+
+    fn emit_load(&mut self, layer: u16, local: u32) {
+        if layer == 0 {
+            self.emit_op(Op::LoadLocal);
+            self.emit_u32(local);
+        } else {
+            self.emit_op(Op::LoadOuter);
+            self.emit_u8(layer as u8);
+            self.emit_u32(local);
+        }
+    }
+
+    fn count_with_thunks(&self, ir: RawIrRef<'_>) -> usize {
+        match ir.deref() {
+            Ir::With { thunks, body, .. } => thunks.len() + self.count_with_thunks(*body),
+            Ir::TopLevel { thunks, body } => thunks.len() + self.count_with_thunks(*body),
+            Ir::If { cond, consq, alter } => {
+                self.count_with_thunks(*cond)
+                    + self.count_with_thunks(*consq)
+                    + self.count_with_thunks(*alter)
+            }
+            Ir::BinOp { lhs, rhs, .. } => {
+                self.count_with_thunks(*lhs) + self.count_with_thunks(*rhs)
+            }
+            Ir::UnOp { rhs, .. } => self.count_with_thunks(*rhs),
+            Ir::Call { func, arg, .. } => {
+                self.count_with_thunks(*func) + self.count_with_thunks(*arg)
+            }
+            Ir::Assert {
+                assertion, expr, ..
+            } => self.count_with_thunks(*assertion) + self.count_with_thunks(*expr),
+            Ir::Select { expr, default, .. } => {
+                self.count_with_thunks(*expr) + default.map_or(0, |d| self.count_with_thunks(d))
+            }
+            Ir::HasAttr { lhs, .. } => self.count_with_thunks(*lhs),
+            Ir::ConcatStrings { parts, .. } => {
+                parts.iter().map(|p| self.count_with_thunks(*p)).sum()
+            }
+            Ir::Path(p) => self.count_with_thunks(*p),
+            Ir::List { items } => items.iter().map(|item| self.count_with_thunks(*item)).sum(),
+            Ir::AttrSet { stcs, dyns } => {
+                stcs.iter()
+                    .map(|(_, &(val, _))| self.count_with_thunks(val))
+                    .sum::<usize>()
+                    + dyns
+                        .iter()
+                        .map(|&(k, v, _)| self.count_with_thunks(k) + self.count_with_thunks(v))
+                        .sum::<usize>()
+            }
+            _ => 0,
+        }
+    }
+
+    fn collect_all_thunks<'ir>(
+        &self,
+        own_thunks: &[(ThunkId, RawIrRef<'ir>)],
+        body: RawIrRef<'ir>,
+    ) -> Vec<(ThunkId, RawIrRef<'ir>)> {
+        let mut all = Vec::from(own_thunks);
+        self.collect_with_thunks_recursive(body, &mut all);
+        let mut i = 0;
+        while i < all.len() {
+            let thunk_body = all[i].1;
+            self.collect_with_thunks_recursive(thunk_body, &mut all);
+            i += 1;
+        }
+        all
+    }
+
+    fn collect_with_thunks_recursive<'ir>(
+        &self,
+        ir: RawIrRef<'ir>,
+        out: &mut Vec<(ThunkId, RawIrRef<'ir>)>,
+    ) {
+        match ir.deref() {
+            Ir::With { thunks, body, .. } => {
+                for &(id, inner) in thunks.iter() {
+                    out.push((id, inner));
+                }
+                self.collect_with_thunks_recursive(*body, out);
+            }
+            Ir::TopLevel { thunks, body } => {
+                for &(id, inner) in thunks.iter() {
+                    out.push((id, inner));
+                }
+                self.collect_with_thunks_recursive(*body, out);
+            }
+            Ir::If { cond, consq, alter } => {
+                self.collect_with_thunks_recursive(*cond, out);
+                self.collect_with_thunks_recursive(*consq, out);
+                self.collect_with_thunks_recursive(*alter, out);
+            }
+            Ir::BinOp { lhs, rhs, .. } => {
+                self.collect_with_thunks_recursive(*lhs, out);
+                self.collect_with_thunks_recursive(*rhs, out);
+            }
+            Ir::UnOp { rhs, .. } => self.collect_with_thunks_recursive(*rhs, out),
+            Ir::Call { func, arg, .. } => {
+                self.collect_with_thunks_recursive(*func, out);
+                self.collect_with_thunks_recursive(*arg, out);
+            }
+            Ir::Assert {
+                assertion, expr, ..
+            } => {
+                self.collect_with_thunks_recursive(*assertion, out);
+                self.collect_with_thunks_recursive(*expr, out);
+            }
+            Ir::Select { expr, default, .. } => {
+                self.collect_with_thunks_recursive(*expr, out);
+                if let Some(d) = default {
+                    self.collect_with_thunks_recursive(*d, out);
+                }
+            }
+            Ir::HasAttr { lhs, .. } => self.collect_with_thunks_recursive(*lhs, out),
+            Ir::ConcatStrings { parts, .. } => {
+                for p in parts.iter() {
+                    self.collect_with_thunks_recursive(*p, out);
+                }
+            }
+            Ir::Path(p) => self.collect_with_thunks_recursive(*p, out),
+            Ir::List { items } => {
+                for item in items.iter() {
+                    self.collect_with_thunks_recursive(*item, out);
+                }
+            }
+            Ir::AttrSet { stcs, dyns } => {
+                for (_, &(val, _)) in stcs.iter() {
+                    self.collect_with_thunks_recursive(val, out);
+                }
+                for &(key, val, _) in dyns.iter() {
+                    self.collect_with_thunks_recursive(key, out);
+                    self.collect_with_thunks_recursive(val, out);
+                }
+            }
+            _ => {}
+        }
+    }
+
+    fn push_scope(&mut self, has_arg: bool, arg_id: Option<ArgId>, thunk_ids: &[ThunkId]) {
+        let depth = self.scope_stack.len() as u16;
+        let thunk_base = if has_arg { 1u32 } else { 0u32 };
+        let thunk_map = thunk_ids
+            .iter()
+            .enumerate()
+            .map(|(i, &id)| (id, thunk_base + i as u32))
+            .collect();
+        self.scope_stack.push(ScopeInfo {
+            depth,
+            arg_id,
+            thunk_map,
+        });
+    }
+
+    fn pop_scope(&mut self) {
+        self.scope_stack.pop();
+    }
+
+    fn emit_toplevel(&mut self, ir: RawIrRef<'_>) {
+        match ir.deref() {
+            Ir::TopLevel { body, thunks } => {
+                let with_thunk_count = self.count_with_thunks(*body);
+                let total_slots = thunks.len() + with_thunk_count;
+
+                let all_thunks = self.collect_all_thunks(thunks, *body);
+                let thunk_ids: Vec<ThunkId> = all_thunks.iter().map(|&(id, _)| id).collect();
+
+                self.push_scope(false, None, &thunk_ids);
+
+                if total_slots > 0 {
+                    self.emit_op(Op::AllocLocals);
+                    self.emit_u32(total_slots as u32);
+                }
+
+                self.emit_scope_thunks(thunks);
+                self.emit_expr(*body);
+                self.emit_op(Op::Return);
+
+                self.pop_scope();
+            }
+            _ => {
+                self.push_scope(false, None, &[]);
+                self.emit_expr(ir);
+                self.emit_op(Op::Return);
+                self.pop_scope();
+            }
+        }
+    }
+
+    fn emit_toplevel_scoped(&mut self, ir: RawIrRef<'_>) {
+        match ir.deref() {
+            Ir::TopLevel { body, thunks } => {
+                let with_thunk_count = self.count_with_thunks(*body);
+                let total_slots = thunks.len() + with_thunk_count;
+
+                let all_thunks = self.collect_all_thunks(thunks, *body);
+                let thunk_ids: Vec<ThunkId> = all_thunks.iter().map(|&(id, _)| id).collect();
+
+                self.push_scope(false, None, &thunk_ids);
+
+                if total_slots > 0 {
+                    self.emit_op(Op::AllocLocals);
+                    self.emit_u32(total_slots as u32);
+                }
+
+                self.emit_scope_thunks(thunks);
+                self.emit_expr(*body);
+                self.emit_op(Op::Return);
+
+                self.pop_scope();
+            }
+            _ => {
+                self.push_scope(false, None, &[]);
+                self.emit_expr(ir);
+                self.emit_op(Op::Return);
+                self.pop_scope();
+            }
+        }
+    }
+
+    fn emit_scope_thunks(&mut self, thunks: &[(ThunkId, RawIrRef<'_>)]) {
+        for &(id, inner) in thunks {
+            let label = format!("e{}", id.0);
+            let label_idx = self.ctx.intern_string(&label);
+
+            let skip_patch = self.emit_jump_placeholder();
+            let entry_point = self.code.len() as u32;
+            self.emit_expr(inner);
+            self.emit_op(Op::Return);
+            self.patch_jump_target(skip_patch);
+            self.emit_op(Op::MakeThunk);
+            self.emit_u32(entry_point);
+            self.emit_u32(label_idx);
+            let (_, local_idx) = self.resolve_thunk(id);
+            self.emit_op(Op::StoreLocal);
+            self.emit_u32(local_idx);
+        }
+    }
+
+    fn emit_expr(&mut self, ir: RawIrRef<'_>) {
+        match ir.deref() {
+            &Ir::Int(x) => {
+                let idx = self.ctx.intern_constant(Constant::Int(x));
+                self.emit_op(Op::PushConst);
+                self.emit_u32(idx);
+            }
+            &Ir::Float(x) => {
+                let idx = self.ctx.intern_constant(Constant::Float(x.to_bits()));
+                self.emit_op(Op::PushConst);
+                self.emit_u32(idx);
+            }
+            &Ir::Bool(true) => self.emit_op(Op::PushTrue),
+            &Ir::Bool(false) => self.emit_op(Op::PushFalse),
+            Ir::Null => self.emit_op(Op::PushNull),
+            Ir::Str(s) => {
+                let idx = self.ctx.intern_string(s.deref());
+                self.emit_op(Op::PushString);
+                self.emit_u32(idx);
+            }
+            &Ir::Path(p) => {
+                self.emit_expr(p);
+                self.emit_op(Op::ResolvePath);
+            }
+            &Ir::If { cond, consq, alter } => {
+                self.emit_expr(cond);
+                self.emit_op(Op::ForceBool);
+
+                self.emit_op(Op::JumpIfFalse);
+                let else_placeholder = self.emit_i32_placeholder();
+                let after_jif = self.code.len();
+
+                self.emit_expr(consq);
+
+                self.emit_op(Op::Jump);
+                let end_placeholder = self.emit_i32_placeholder();
+                let after_jump = self.code.len();
+
+                let else_offset = (after_jump as i32) - (after_jif as i32);
+                self.patch_i32(else_placeholder, else_offset);
+
+                self.emit_expr(alter);
+
+                let end_offset = (self.code.len() as i32) - (after_jump as i32);
+                self.patch_i32(end_placeholder, end_offset);
+            }
+            &Ir::BinOp { lhs, rhs, kind } => {
+                self.emit_binop(lhs, rhs, kind);
+            }
+            &Ir::UnOp { rhs, kind } => match kind {
+                UnOpKind::Neg => {
+                    self.emit_expr(rhs);
+                    self.emit_op(Op::OpNeg);
+                }
+                UnOpKind::Not => {
+                    self.emit_expr(rhs);
+                    self.emit_op(Op::OpNot);
+                }
+            },
+            &Ir::Func {
+                body,
+                ref param,
+                arg,
+                ref thunks,
+            } => {
+                self.emit_func(arg, thunks, param, body);
+            }
+            Ir::AttrSet { stcs, dyns } => {
+                self.emit_attrset(stcs, dyns);
+            }
+            Ir::List { items } => {
+                for &item in items.iter() {
+                    self.emit_expr(item);
+                }
+                self.emit_op(Op::MakeList);
+                self.emit_u32(items.len() as u32);
+            }
+            &Ir::Call { func, arg, span } => {
+                self.emit_expr(func);
+                self.emit_expr(arg);
+                let span_id = self.ctx.register_span(span);
+                self.emit_op(Op::Call);
+                self.emit_u32(span_id);
+            }
+            &Ir::Arg(id) => {
+                let (layer, local) = self.resolve_arg(id);
+                self.emit_load(layer, local);
+            }
+            &Ir::TopLevel { body, ref thunks } => {
+                self.emit_toplevel_inner(body, thunks);
+            }
+            &Ir::Select {
+                expr,
+                ref attrpath,
+                default,
+                span,
+            } => {
+                self.emit_select(expr, attrpath, default, span);
+            }
+            &Ir::Thunk(id) => {
+                let (layer, local) = self.resolve_thunk(id);
+                self.emit_load(layer, local);
+            }
+            Ir::Builtins => {
+                self.emit_op(Op::LoadBuiltins);
+            }
+            &Ir::Builtin(name) => {
+                let sym = self.ctx.get_sym(name).to_string();
+                let idx = self.ctx.intern_string(&sym);
+                self.emit_op(Op::LoadBuiltin);
+                self.emit_u32(idx);
+            }
+            &Ir::ConcatStrings {
+                ref parts,
+                force_string,
+            } => {
+                for &part in parts.iter() {
+                    self.emit_expr(part);
+                }
+                self.emit_op(Op::ConcatStrings);
+                self.emit_u16(parts.len() as u16);
+                self.emit_u8(if force_string { 1 } else { 0 });
+            }
+            &Ir::HasAttr { lhs, ref rhs } => {
+                self.emit_has_attr(lhs, rhs);
+            }
+            Ir::Assert {
+                assertion,
+                expr,
+                assertion_raw,
+                span,
+            } => {
+                let raw_idx = self.ctx.intern_string(assertion_raw);
+                let span_id = self.ctx.register_span(*span);
+                self.emit_expr(*assertion);
+                self.emit_expr(*expr);
+                self.emit_op(Op::Assert);
+                self.emit_u32(raw_idx);
+                self.emit_u32(span_id);
+            }
+            &Ir::CurPos(span) => {
+                let span_id = self.ctx.register_span(span);
+                self.emit_op(Op::MkPos);
+                self.emit_u32(span_id);
+            }
+            &Ir::ReplBinding(name) => {
+                let sym = self.ctx.get_sym(name).to_string();
+                let idx = self.ctx.intern_string(&sym);
+                self.emit_op(Op::LoadReplBinding);
+                self.emit_u32(idx);
+            }
+            &Ir::ScopedImportBinding(name) => {
+                let sym = self.ctx.get_sym(name).to_string();
+                let idx = self.ctx.intern_string(&sym);
+                self.emit_op(Op::LoadScopedBinding);
+                self.emit_u32(idx);
+            }
+            &Ir::With {
+                namespace,
+                body,
+                ref thunks,
+            } => {
+                self.emit_with(namespace, body, thunks);
+            }
+            &Ir::WithLookup(name) => {
+                let sym = self.ctx.get_sym(name).to_string();
+                let idx = self.ctx.intern_string(&sym);
+                self.emit_op(Op::WithLookup);
+                self.emit_u32(idx);
+            }
+        }
+    }
+
+    fn emit_binop(&mut self, lhs: RawIrRef<'_>, rhs: RawIrRef<'_>, kind: BinOpKind) {
+        use BinOpKind::*;
+        match kind {
+            And => {
+                self.emit_expr(lhs);
+                self.emit_op(Op::ForceBool);
+                self.emit_op(Op::JumpIfFalse);
+                let skip_placeholder = self.emit_i32_placeholder();
+                let after_jif = self.code.len();
+
+                self.emit_expr(rhs);
+                self.emit_op(Op::ForceBool);
+                self.emit_op(Op::Jump);
+                let end_placeholder = self.emit_i32_placeholder();
+                let after_jump = self.code.len();
+
+                let false_offset = (after_jump as i32) - (after_jif as i32);
+                self.patch_i32(skip_placeholder, false_offset);
+
+                self.emit_op(Op::PushFalse);
+
+                let end_offset = (self.code.len() as i32) - (after_jump as i32);
+                self.patch_i32(end_placeholder, end_offset);
+            }
+            Or => {
+                self.emit_expr(lhs);
+                self.emit_op(Op::ForceBool);
+                self.emit_op(Op::JumpIfTrue);
+                let skip_placeholder = self.emit_i32_placeholder();
+                let after_jit = self.code.len();
+
+                self.emit_expr(rhs);
+                self.emit_op(Op::ForceBool);
+                self.emit_op(Op::Jump);
+                let end_placeholder = self.emit_i32_placeholder();
+                let after_jump = self.code.len();
+
+                let true_offset = (after_jump as i32) - (after_jit as i32);
+                self.patch_i32(skip_placeholder, true_offset);
+
+                self.emit_op(Op::PushTrue);
+
+                let end_offset = (self.code.len() as i32) - (after_jump as i32);
+                self.patch_i32(end_placeholder, end_offset);
+            }
+            Impl => {
+                self.emit_expr(lhs);
+                self.emit_op(Op::ForceBool);
+                self.emit_op(Op::JumpIfFalse);
+                let skip_placeholder = self.emit_i32_placeholder();
+                let after_jif = self.code.len();
+
+                self.emit_expr(rhs);
+                self.emit_op(Op::ForceBool);
+                self.emit_op(Op::Jump);
+                let end_placeholder = self.emit_i32_placeholder();
+                let after_jump = self.code.len();
+
+                let true_offset = (after_jump as i32) - (after_jif as i32);
+                self.patch_i32(skip_placeholder, true_offset);
+
+                self.emit_op(Op::PushTrue);
+
+                let end_offset = (self.code.len() as i32) - (after_jump as i32);
+                self.patch_i32(end_placeholder, end_offset);
+            }
+            PipeL => {
+                self.emit_expr(rhs);
+                self.emit_expr(lhs);
+                self.emit_op(Op::CallNoSpan);
+            }
+            PipeR => {
+                self.emit_expr(lhs);
+                self.emit_expr(rhs);
+                self.emit_op(Op::CallNoSpan);
+            }
+            _ => {
+                self.emit_expr(lhs);
+                self.emit_expr(rhs);
+                self.emit_op(match kind {
+                    Add => Op::OpAdd,
+                    Sub => Op::OpSub,
+                    Mul => Op::OpMul,
+                    Div => Op::OpDiv,
+                    Eq => Op::OpEq,
+                    Neq => Op::OpNeq,
+                    Lt => Op::OpLt,
+                    Gt => Op::OpGt,
+                    Leq => Op::OpLeq,
+                    Geq => Op::OpGeq,
+                    Con => Op::OpConcat,
+                    Upd => Op::OpUpdate,
+                    _ => unreachable!(),
+                });
+            }
+        }
+    }
+
+    fn emit_func(
+        &mut self,
+        arg: ArgId,
+        thunks: &[(ThunkId, RawIrRef<'_>)],
+        param: &Option<Param<'_>>,
+        body: RawIrRef<'_>,
+    ) {
+        let with_thunk_count = self.count_with_thunks(body);
+        let total_slots = thunks.len() + with_thunk_count;
+
+        let all_thunks = self.collect_all_thunks(thunks, body);
+        let thunk_ids: Vec<ThunkId> = all_thunks.iter().map(|&(id, _)| id).collect();
+
+        let skip_patch = self.emit_jump_placeholder();
+        let entry_point = self.code.len() as u32;
+        self.push_scope(true, Some(arg), &thunk_ids);
+        self.emit_scope_thunks(thunks);
+        self.emit_expr(body);
+        self.emit_op(Op::Return);
+        self.pop_scope();
+        self.patch_jump_target(skip_patch);
+
+        if let Some(Param {
+            required,
+            optional,
+            ellipsis,
+        }) = param
+        {
+            self.emit_op(Op::MakePatternClosure);
+            self.emit_u32(entry_point);
+            self.emit_u32(total_slots as u32);
+            self.emit_u16(required.len() as u16);
+            self.emit_u16(optional.len() as u16);
+            self.emit_u8(if *ellipsis { 1 } else { 0 });
+
+            for &(sym, _) in required.iter() {
+                let name = self.ctx.get_sym(sym).to_string();
+                let idx = self.ctx.intern_string(&name);
+                self.emit_u32(idx);
+            }
+            for &(sym, _) in optional.iter() {
+                let name = self.ctx.get_sym(sym).to_string();
+                let idx = self.ctx.intern_string(&name);
+                self.emit_u32(idx);
+            }
+            for &(sym, span) in required.iter().chain(optional.iter()) {
+                let name = self.ctx.get_sym(sym).to_string();
+                let name_idx = self.ctx.intern_string(&name);
+                let span_id = self.ctx.register_span(span);
+                self.emit_u32(name_idx);
+                self.emit_u32(span_id);
+            }
+        } else {
+            self.emit_op(Op::MakeClosure);
+            self.emit_u32(entry_point);
+            self.emit_u32(total_slots as u32);
+        }
+    }
+
+    fn emit_attrset(
+        &mut self,
+        stcs: &crate::ir::HashMap<'_, SymId, (RawIrRef<'_>, TextRange)>,
+        dyns: &[(RawIrRef<'_>, RawIrRef<'_>, TextRange)],
+    ) {
+        if stcs.is_empty() && dyns.is_empty() {
+            self.emit_op(Op::MakeEmptyAttrs);
+            return;
+        }
+
+        if !dyns.is_empty() {
+            for (&sym, &(val, _)) in stcs.iter() {
+                let key = self.ctx.get_sym(sym).to_string();
+                let idx = self.ctx.intern_string(&key);
+                self.emit_op(Op::PushString);
+                self.emit_u32(idx);
+                self.emit_expr(val);
+            }
+            for (_, &(_, span)) in stcs.iter() {
+                let span_id = self.ctx.register_span(span);
+                let idx = self.ctx.intern_constant(Constant::Int(span_id as i64));
+                self.emit_op(Op::PushConst);
+                self.emit_u32(idx);
+            }
+            for &(key, val, span) in dyns.iter() {
+                self.emit_expr(key);
+                self.emit_expr(val);
+                let span_id = self.ctx.register_span(span);
+                let idx = self.ctx.intern_constant(Constant::Int(span_id as i64));
+                self.emit_op(Op::PushConst);
+                self.emit_u32(idx);
+            }
+            self.emit_op(Op::MakeAttrsDyn);
+            self.emit_u32(stcs.len() as u32);
+            self.emit_u32(dyns.len() as u32);
+        } else {
+            for (&sym, &(val, _)) in stcs.iter() {
+                let key = self.ctx.get_sym(sym).to_string();
+                let idx = self.ctx.intern_string(&key);
+                self.emit_op(Op::PushString);
+                self.emit_u32(idx);
+                self.emit_expr(val);
+            }
+            for (_, &(_, span)) in stcs.iter() {
+                let span_id = self.ctx.register_span(span);
+                let idx = self.ctx.intern_constant(Constant::Int(span_id as i64));
+                self.emit_op(Op::PushConst);
+                self.emit_u32(idx);
+            }
+            self.emit_op(Op::MakeAttrs);
+            self.emit_u32(stcs.len() as u32);
+        }
+    }
+
+    fn emit_select(
+        &mut self,
+        expr: RawIrRef<'_>,
+        attrpath: &[Attr<RawIrRef<'_>>],
+        default: Option<RawIrRef<'_>>,
+        span: TextRange,
+    ) {
+        self.emit_expr(expr);
+        for attr in attrpath.iter() {
+            match attr {
+                Attr::Str(sym, _) => {
+                    let key = self.ctx.get_sym(*sym).to_string();
+                    let idx = self.ctx.intern_string(&key);
+                    self.emit_op(Op::PushString);
+                    self.emit_u32(idx);
+                }
+                Attr::Dynamic(expr, _) => {
+                    self.emit_expr(*expr);
+                }
+            }
+        }
+
+        if let Some(default) = default {
+            self.emit_expr(default);
+            let span_id = self.ctx.register_span(span);
+            self.emit_op(Op::SelectDefault);
+            self.emit_u16(attrpath.len() as u16);
+            self.emit_u32(span_id);
+        } else {
+            let span_id = self.ctx.register_span(span);
+            self.emit_op(Op::Select);
+            self.emit_u16(attrpath.len() as u16);
+            self.emit_u32(span_id);
+        }
+    }
+
+    fn emit_has_attr(&mut self, lhs: RawIrRef<'_>, rhs: &[Attr<RawIrRef<'_>>]) {
+        self.emit_expr(lhs);
+        for attr in rhs.iter() {
+            match attr {
+                Attr::Str(sym, _) => {
+                    let key = self.ctx.get_sym(*sym).to_string();
+                    let idx = self.ctx.intern_string(&key);
+                    self.emit_op(Op::PushString);
+                    self.emit_u32(idx);
+                }
+                Attr::Dynamic(expr, _) => {
+                    self.emit_expr(*expr);
+                }
+            }
+        }
+        self.emit_op(Op::HasAttr);
+        self.emit_u16(rhs.len() as u16);
+    }
+
+    fn emit_with(
+        &mut self,
+        namespace: RawIrRef<'_>,
+        body: RawIrRef<'_>,
+        thunks: &[(ThunkId, RawIrRef<'_>)],
+    ) {
+        self.emit_expr(namespace);
+        self.emit_op(Op::PushWith);
+        self.emit_scope_thunks(thunks);
+        self.emit_expr(body);
+        self.emit_op(Op::PopWith);
+    }
+
+    fn emit_toplevel_inner(&mut self, body: RawIrRef<'_>, thunks: &[(ThunkId, RawIrRef<'_>)]) {
+        self.emit_scope_thunks(thunks);
+        self.emit_expr(body);
+    }
+}
--- a/nix-js/src/codegen.rs
+++ b/nix-js/src/codegen.rs
@@ -1,6 +1,9 @@
 use std::fmt::{self, Write as _};
+use std::ops::Deref;
 use std::path::Path;

+use rnix::TextRange;
+
 use crate::ir::*;
 use crate::value::Symbol;

@@ -26,50 +29,23 @@ macro_rules! code {
    };
 }

-pub(crate) fn compile(expr: &Ir, ctx: &impl CodegenContext) -> String {
+pub(crate) fn compile<const SCOPED: bool>(expr: RawIrRef<'_>, ctx: &impl CodegenContext) -> String {
    let mut buf = CodeBuffer::with_capacity(8192);

-    code!(&mut buf, ctx; "(()=>{");
-
-    if std::env::var("NIX_JS_DEBUG_THUNKS").is_ok() {
-        code!(&mut buf, ctx; "Nix.DEBUG_THUNKS.enabled=true;");
-    }
-
-    code!(&mut buf, ctx;
-        "Nix.builtins.storeDir="
-        quoted(ctx.get_store_dir())
-        ";const __currentDir="
+    code!(
+        &mut buf, ctx;
+        "((" { if SCOPED { "_s" } else { "" } } ")=>{"
+            "const _d="
                quoted(&ctx.get_current_dir().display().to_string())
-        ";const __with=null;return "
-        expr
-        "})()");
-
-    buf.into_string()
-}
-
-pub(crate) fn compile_scoped(expr: &Ir, ctx: &impl CodegenContext) -> String {
-    let mut buf = CodeBuffer::with_capacity(8192);
-
-    code!(&mut buf, ctx; "((__scope)=>{");
-
-    if std::env::var("NIX_JS_DEBUG_THUNKS").is_ok() {
-        code!(&mut buf, ctx; "Nix.DEBUG_THUNKS.enabled=true;");
-    }
-
-    code!(&mut buf, ctx;
-        "Nix.builtins.storeDir="
-        quoted(ctx.get_store_dir())
-        ";const __currentDir="
-        quoted(&ctx.get_current_dir().display().to_string())
-        ";return "
-        expr
-        "})"
+            ",_w=null;"
+            "return " expr
+        "})" { if SCOPED { "" } else { "()" } }
    );

    buf.into_string()
 }

-pub(crate) struct CodeBuffer {
+struct CodeBuffer {
    buf: String,
 }

@@ -195,29 +171,16 @@ where

 impl<Ctx: CodegenContext> Compile<Ctx> for rnix::TextRange {
    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        code!(
-            buf,
-            "\"{}:{}:{}\"",
-            ctx.get_current_source_id(),
-            usize::from(self.start()),
-            usize::from(self.end())
-        );
+        code!(buf, "{}", ctx.register_span(*self));
    }
 }

 pub(crate) trait CodegenContext {
-    fn get_ir(&self, id: ExprId) -> &Ir;
    fn get_sym(&self, id: SymId) -> Symbol<'_>;
    fn get_current_dir(&self) -> &Path;
    fn get_store_dir(&self) -> &str;
    fn get_current_source_id(&self) -> usize;
-    fn get_current_source(&self) -> crate::error::Source;
-}
-
-impl<Ctx: CodegenContext> Compile<Ctx> for ExprId {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        ctx.get_ir(*self).compile(ctx, buf);
-    }
+    fn register_span(&self, range: rnix::TextRange) -> usize;
 }

 impl<Ctx: CodegenContext> Compile<Ctx> for Symbol<'_> {
@@ -226,70 +189,90 @@ impl<Ctx: CodegenContext> Compile<Ctx> for Symbol<'_> {
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for Ir {
+impl<Ctx: CodegenContext> Compile<Ctx> for RawIrRef<'_> {
    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        match self {
+        match self.deref() {
            Ir::Int(int) => {
-                code!(buf, "{}n", int.inner);
+                code!(buf, "{}n", int);
            }
            Ir::Float(float) => {
-                code!(buf, "{}", float.inner);
+                code!(buf, "{}", float);
            }
            Ir::Bool(bool) => {
-                code!(buf, "{}", bool.inner);
+                code!(buf, "{}", bool);
            }
-            Ir::Null(_) => {
+            Ir::Null => {
                code!(buf, ctx; "null");
            }
            Ir::Str(s) => {
-                code!(buf, ctx; quoted(&s.val));
+                code!(buf, ctx; quoted(s));
            }
            Ir::Path(p) => {
-                code!(buf, ctx; "Nix.resolvePath(__currentDir," ctx.get_ir(p.expr) ")");
+                // Nix.resolvePath
+                code!(buf, ctx; "$r(_d," p ")");
            }
-            Ir::If(x) => x.compile(ctx, buf),
-            Ir::BinOp(x) => x.compile(ctx, buf),
-            Ir::UnOp(x) => x.compile(ctx, buf),
-            Ir::Func(x) => x.compile(ctx, buf),
-            Ir::AttrSet(x) => x.compile(ctx, buf),
-            Ir::List(x) => x.compile(ctx, buf),
-            Ir::Call(x) => x.compile(ctx, buf),
-            Ir::Arg(x) => {
-                code!(buf, "arg{}", x.inner.0);
+            Ir::If { cond, consq, alter } => {
+                code!(buf, ctx; "$fb(" cond ")?(" consq "):(" alter ")");
            }
-            Ir::TopLevel(x) => x.compile(ctx, buf),
-            Ir::Select(x) => x.compile(ctx, buf),
-            &Ir::Thunk(Thunk { inner: expr_id, .. }) => {
-                code!(buf, "expr{}", expr_id.0);
-            }
-            Ir::Builtins(_) => {
-                code!(buf, ctx; "Nix.builtins");
-            }
-            &Ir::Builtin(Builtin { inner: name, .. }) => {
+            &Ir::BinOp { lhs, rhs, kind } => compile_binop(lhs, rhs, kind, ctx, buf),
+            &Ir::UnOp { rhs, kind } => compile_unop(rhs, kind, ctx, buf),
+            &Ir::Func {
+                body,
+                ref param,
+                arg,
+                ref thunks,
+            } => compile_func(arg, thunks, param, body, ctx, buf),
+            Ir::AttrSet { stcs, dyns } => compile_attrset(stcs, dyns, ctx, buf),
+            Ir::List { items } => compile_list(items, ctx, buf),
+            Ir::Call { func, arg, span } => {
                code!(buf, ctx;
-                    "Nix.builtins["
-                        ctx.get_sym(name)
-                    "]"
+                    "$c("
+                        func
+                        ","
+                        arg
+                        ","
+                        span
+                    ")"
                );
            }
-            Ir::ConcatStrings(x) => x.compile(ctx, buf),
-            Ir::HasAttr(x) => x.compile(ctx, buf),
-            &Ir::Assert(Assert {
+            Ir::Arg(x) => {
+                code!(buf, "a{}", x.0);
+            }
+            &Ir::TopLevel { body, ref thunks } => compile_toplevel(body, thunks, ctx, buf),
+            &Ir::Select {
+                expr,
+                ref attrpath,
+                default,
+                span,
+            } => compile_select(expr, attrpath, default, span, ctx, buf),
+            Ir::Thunk(ThunkId(id)) => {
+                code!(buf, "e{}", id);
+            }
+            Ir::Builtins => {
+                // Nix.builtins
+                code!(buf, ctx; "$b");
+            }
+            &Ir::Builtin(name) => {
+                // Nix.builtins
+                code!(buf, ctx; "$b.get(" ctx.get_sym(name) ")");
+            }
+            &Ir::ConcatStrings {
+                ref parts,
+                force_string,
+            } => compile_concat_strings(parts, force_string, ctx, buf),
+            &Ir::HasAttr { lhs, ref rhs } => compile_has_attr(lhs, rhs, ctx, buf),
+            Ir::Assert {
                assertion,
                expr,
-                ref assertion_raw,
+                assertion_raw,
                span: assert_span,
-            }) => {
-                let assertion_ir = ctx.get_ir(assertion);
-                let assertion_span = assertion_ir.span();
-
+            } => {
+                // Nix.assert
                code!(buf, ctx;
-                    "Nix.assert(Nix.withContext(\"while evaluating the condition of the assert statement\","
-                    assertion_span
-                    ",()=>("
-                    assertion_ir
-                    ")),"
-                    ctx.get_ir(expr)
+                    "$a("
+                        assertion
+                        ","
+                        expr
                        ","
                        quoted(assertion_raw)
                        ","
@@ -297,162 +280,127 @@ impl<Ctx: CodegenContext> Compile<Ctx> for Ir {
                    ")"
                );
            }
-            Ir::CurPos(cur_pos) => {
-                code!(buf, ctx;
-                    "Nix.mkPos("
-                    cur_pos.span
-                    ")"
-                );
+            Ir::CurPos(span) => {
+                // Nix.mkPos
+                code!(buf, ctx; "$mp(" span ")");
            }
-            &Ir::ReplBinding(ReplBinding { inner: name, .. }) => {
-                code!(buf, ctx;
-                    "Nix.getReplBinding("
-                    ctx.get_sym(name)
-                    ")"
-                );
+            &Ir::ReplBinding(name) => {
+                // Nix.getReplBinding
+                code!(buf, ctx; "$gb(" ctx.get_sym(name) ")");
            }
-            &Ir::ScopedImportBinding(ScopedImportBinding { inner: name, .. }) => {
-                code!(buf, ctx;
-                    "__scope["
-                    ctx.get_sym(name)
-                    "]"
-                );
+            &Ir::ScopedImportBinding(name) => {
+                code!(buf, ctx; "_s.get(" ctx.get_sym(name) ")");
            }
-            Ir::WithExpr(x) => x.compile(ctx, buf),
-            &Ir::WithLookup(WithLookup { inner: name, .. }) => {
-                code!(buf, ctx;
-                    "Nix.lookupWith("
-                    ctx.get_sym(name)
-                    ",__with)"
-                );
+            &Ir::With {
+                namespace,
+                body,
+                ref thunks,
+            } => compile_with(namespace, body, thunks, ctx, buf),
+            &Ir::WithLookup(name) => {
+                // Nix.lookupWith
+                code!(buf, ctx; "$l(" ctx.get_sym(name) ",_w)");
            }
        }
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for If {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        let &If {
-            cond,
-            consq,
-            alter,
-            span: _,
-        } = self;
-        let cond_ir = ctx.get_ir(cond);
-        let cond_span = cond_ir.span();
-
-        code!(buf, ctx;
-            "(Nix.withContext(\"while evaluating a branch condition\"," cond_span ",()=>Nix.forceBool(" cond_ir ")))"
-            "?(" consq "):(" alter ")"
-        );
-    }
-}
-
-impl<Ctx: CodegenContext> Compile<Ctx> for BinOp {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
+fn compile_binop<'ir>(
+    lhs: RawIrRef<'ir>,
+    rhs: RawIrRef<'ir>,
+    kind: BinOpKind,
+    ctx: &impl CodegenContext,
+    buf: &mut CodeBuffer,
+) {
    use BinOpKind::*;
-
-        let lhs = ctx.get_ir(self.lhs);
-        let rhs = ctx.get_ir(self.rhs);
-
-        match self.kind {
+    match kind {
        Add | Sub | Mul | Div | Eq | Neq | Lt | Gt | Leq | Geq | Con | Upd => {
-                let op_name = match self.kind {
-                    Add => "+",
-                    Sub => "-",
-                    Mul => "*",
-                    Div => "/",
-                    Eq => "==",
-                    Neq => "!=",
-                    Lt => "<",
-                    Gt => ">",
-                    Leq => "<=",
-                    Geq => ">=",
-                    Con => "++",
-                    Upd => "//",
-                    _ => unreachable!(),
-                };
-                let op_func = match self.kind {
-                    Add => "Nix.op.add",
-                    Sub => "Nix.op.sub",
-                    Mul => "Nix.op.mul",
-                    Div => "Nix.op.div",
-                    Eq => "Nix.op.eq",
-                    Neq => "Nix.op.neq",
-                    Lt => "Nix.op.lt",
-                    Gt => "Nix.op.gt",
-                    Leq => "Nix.op.lte",
-                    Geq => "Nix.op.gte",
-                    Con => "Nix.op.concat",
-                    Upd => "Nix.op.update",
+            let op_func = match kind {
+                Add => "$oa",
+                Sub => "$os",
+                Mul => "$om",
+                Div => "$od",
+                Eq => "$oe",
+                Neq => "!$oe",
+                Lt => "$ol",
+                Gt => "$og",
+                Leq => "!$og",
+                Geq => "!$ol",
+                Con => "$oc",
+                Upd => "$ou",
                _ => unreachable!(),
            };

            code!(
                buf, ctx;
-                    "Nix.withContext(\"while evaluating the " op_name " operator\"," self.span ",()=>(" op_func "(" lhs "," rhs ")))"
+                op_func "(" lhs "," rhs ")"
            );
        }
        And => {
            code!(
                buf, ctx;
-                    "Nix.withContext(\"while evaluating the && operator\"," self.span ",()=>(Nix.forceBool(" lhs ")&&Nix.forceBool(" rhs ")))"
+                "$fb(" lhs ")" "&&" "$fb(" rhs ")"
            );
        }
        Or => {
            code!(
                buf, ctx;
-                    "Nix.withContext(\"while evaluating the || operator\"," self.span ",()=>(Nix.forceBool(" lhs ")||Nix.forceBool(" rhs ")))"
+                "$fb(" lhs ")" "||" "$fb(" rhs ")"
            );
        }
        Impl => {
            code!(
                buf, ctx;
-                    "Nix.withContext(\"while evaluating the -> operator\"," self.span ",()=>(!Nix.forceBool(" lhs ")||Nix.forceBool(" rhs ")))"
+                "!$fb(" lhs ")" "||" "$fb(" rhs ")"
            );
        }
        PipeL => {
-                code!(buf, ctx; "Nix.call(" rhs "," lhs ")");
+            code!(buf, ctx; "$c(" rhs "," lhs ")");
        }
        PipeR => {
-                code!(buf, ctx; "Nix.call(" lhs "," rhs ")");
-            }
+            code!(buf, ctx; "$c(" lhs "," rhs ")");
        }
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for UnOp {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
+fn compile_unop(
+    rhs: RawIrRef<'_>,
+    kind: UnOpKind,
+    ctx: &impl CodegenContext,
+    buf: &mut CodeBuffer,
+) {
    use UnOpKind::*;
-        let rhs = ctx.get_ir(self.rhs);
-        match self.kind {
+    match kind {
        Neg => {
-                code!(buf, ctx; "Nix.op.sub(0n," rhs ")");
+            // 0 - rhs
+            code!(buf, ctx; "$os(0n," rhs ")");
        }
        Not => {
-                code!(buf, ctx; "Nix.op.bnot(" ctx.get_ir(self.rhs) ")");
-            }
+            code!(buf, ctx; "!$fb(" rhs ")");
        }
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for Func {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        let id = ctx.get_ir(self.arg).as_ref().unwrap_arg().inner.0;
-
-        let has_thunks = !self.thunks.is_empty();
+fn compile_func<'ir, Ctx: CodegenContext>(
+    ArgId(id): ArgId,
+    thunks: &[(ThunkId, RawIrRef<'ir>)],
+    param: &Option<Param<'ir>>,
+    body: RawIrRef<'ir>,
+    ctx: &Ctx,
+    buf: &mut CodeBuffer,
+) {
+    let has_thunks = !thunks.is_empty();

    if let Some(Param {
        required,
        optional,
        ellipsis,
-        }) = &self.param
+    }) = &param
    {
-            code!(buf, "Nix.mkFunction(arg{}=>", id);
+        code!(buf, "$mf(a{}=>", id);
        if has_thunks {
-                code!(buf, ctx; "{" self.thunks "return " self.body "}");
+            code!(buf, ctx; "{" thunks "return " body "}");
        } else {
-                code!(buf, ctx; "(" self.body ")");
+            code!(buf, ctx; "(" body ")");
        }
        code!(buf, ctx;
            ",["
@@ -463,229 +411,208 @@ impl<Ctx: CodegenContext> Compile<Ctx> for Func {
            joined(optional.iter(), ",", |ctx: &Ctx, buf, &(sym, _)| {
                code!(buf, ctx; ctx.get_sym(sym));
            })
-                "],{"
+            "],new Map(["
            joined(required.iter().chain(optional.iter()), ",", |ctx: &Ctx, buf, &(sym, span)| {
-                    code!(buf, ctx; ctx.get_sym(sym) ":" span);
+                code!(buf, ctx; "[" ctx.get_sym(sym) "," span "]");
            })
-                "},"
+            "]),"
            ellipsis
            ")"
        );
    } else {
-            code!(buf, "arg{}=>", id);
+        code!(buf, "a{}=>", id);
        if has_thunks {
-                code!(buf, ctx; "{" self.thunks "return " self.body "}");
+            code!(buf, ctx; "{" thunks "return " body "}");
        } else {
-                code!(buf, ctx; "(" self.body ")");
-            }
+            code!(buf, ctx; "(" body ")");
        }
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for Call {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        code!(buf, ctx;
-            "Nix.call("
-                ctx.get_ir(self.func)
-                ","
-                ctx.get_ir(self.arg)
-                ","
-                self.span
-            ")"
-        );
-    }
-}
-
-impl<Ctx: CodegenContext> Compile<Ctx> for [(ExprId, ExprId)] {
+impl<'ir, Ctx: CodegenContext> Compile<Ctx> for [(ThunkId, RawIrRef<'ir>)] {
    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
        if self.is_empty() {
            return;
        }

-        for &(slot, inner) in self {
-            let inner_ir = ctx.get_ir(inner);
-            let inner_span = inner_ir.span();
-
        code!(
            buf, ctx;
-                "let expr" slot.0 "=Nix.createThunk(()=>(" inner_ir "),"
-                "\"expr" slot.0 " "
-                ctx.get_current_source().get_name() ":"
-                usize::from(inner_span.start()) ":"
-                usize::from(inner_span.end())
-                "\");"
+            "const "
+            joined(self.iter(), ",", |ctx: &Ctx, buf, &(slot, inner)| {
+                code!(buf, ctx; "e" slot.0 "=$t(()=>(" inner ")," "'e" slot.0 "')");
+            })
+            ";"
        );
    }
 }
-}

-impl<Ctx: CodegenContext> Compile<Ctx> for TopLevel {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        if self.thunks.is_empty() {
-            ctx.get_ir(self.body).compile(ctx, buf);
+fn compile_toplevel<'ir, Ctx: CodegenContext>(
+    body: RawIrRef<'ir>,
+    thunks: &[(ThunkId, RawIrRef<'ir>)],
+    ctx: &Ctx,
+    buf: &mut CodeBuffer,
+) {
+    if thunks.is_empty() {
+        body.compile(ctx, buf);
    } else {
-            let body = ctx.get_ir(self.body);
-            code!(buf, ctx; "(()=>{" self.thunks "return " body "})()");
-        }
+        code!(buf, ctx; "(()=>{" thunks "return " body "})()");
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for WithExpr {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        let namespace = ctx.get_ir(self.namespace);
-        let body = ctx.get_ir(self.body);
-        let has_thunks = !self.thunks.is_empty();
+fn compile_with<'ir>(
+    namespace: RawIrRef<'ir>,
+    body: RawIrRef<'ir>,
+    thunks: &[(ThunkId, RawIrRef<'ir>)],
+    ctx: &impl CodegenContext,
+    buf: &mut CodeBuffer,
+) {
+    let has_thunks = !thunks.is_empty();
    if has_thunks {
-            code!(buf, ctx; "((__with)=>{" self.thunks "return " body "})({env:" namespace ",last:__with})");
+        code!(buf, ctx; "((_w)=>{" thunks "return " body "})({env:" namespace ",last:_w})");
    } else {
-            code!(buf, ctx; "((__with)=>(" body "))({env:" namespace ",last:__with})");
-        }
+        code!(buf, ctx; "((_w)=>(" body "))({env:" namespace ",last:_w})");
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for Select {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        if let Some(default) = self.default {
+fn compile_select<'ir, Ctx: CodegenContext>(
+    expr: RawIrRef<'ir>,
+    attrpath: &[Attr<RawIrRef<'ir>>],
+    default: Option<RawIrRef<'ir>>,
+    span: TextRange,
+    ctx: &Ctx,
+    buf: &mut CodeBuffer,
+) {
+    if let Some(default) = default {
        code!(buf, ctx;
-                "Nix.selectWithDefault("
-                ctx.get_ir(self.expr)
+            "$sd("
+            expr
            ",["
-                joined(self.attrpath.iter(), ",", |ctx: &Ctx, buf, attr| {
+            joined(attrpath.iter(), ",", |ctx: &Ctx, buf, attr| {
                match attr {
                    Attr::Str(sym, _) => code!(buf, ctx; ctx.get_sym(*sym)),
-                        Attr::Dynamic(expr_id, _) => code!(buf, ctx; ctx.get_ir(*expr_id)),
+                    Attr::Dynamic(expr_id, _) => code!(buf, ctx; *expr_id),
                }
            })
            "],"
-                ctx.get_ir(default)
+            default
            ","
-                self.span
+            span
            ")"
        );
    } else {
        code!(buf, ctx;
-                "Nix.select("
-                ctx.get_ir(self.expr)
+            "$s("
+            expr
            ",["
-                joined(self.attrpath.iter(), ",", |ctx: &Ctx, buf, attr| {
+            joined(attrpath.iter(), ",", |ctx: &Ctx, buf, attr| {
                match attr {
                    Attr::Str(sym, _) => code!(buf, ctx; ctx.get_sym(*sym)),
-                        Attr::Dynamic(expr_id, _) => code!(buf, ctx; ctx.get_ir(*expr_id)),
+                    Attr::Dynamic(expr, _) => code!(buf, ctx; expr),
                }
            })
            "],"
-                self.span
+            span
            ")"
        );
    }
 }
-}

-impl<Ctx: CodegenContext> Compile<Ctx> for AttrSet {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
-        if !self.dyns.is_empty() {
+fn compile_attrset<'ir, Ctx: CodegenContext>(
+    stcs: &HashMap<'ir, SymId, (RawIrRef<'ir>, TextRange)>,
+    dyns: &[(RawIrRef<'ir>, RawIrRef<'ir>, TextRange)],
+    ctx: &Ctx,
+    buf: &mut CodeBuffer,
+) {
+    if !dyns.is_empty() {
        code!(buf, ctx;
-                "Nix.mkAttrsWithPos({"
-                joined(self.stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(expr, _))| {
+            "$ma(new Map(["
+            joined(stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(val, _))| {
                let key = ctx.get_sym(sym);
-                    let val = ctx.get_ir(expr);
-
                code!(
                    buf, ctx;
-                        key ":Nix.withContext(\"while evaluating the attribute '" escaped(&key) "'\"," val.span() ",()=>(" val "))"
+                    "[" key "," val "]"
                );
            })
-                "},{"
-                joined(self.stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(_, span))| {
-                    code!(buf, ctx; ctx.get_sym(sym) ":" span);
+            "]),new Map(["
+            joined(stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(_, span))| {
+                code!(buf, ctx; "[" ctx.get_sym(sym) "," span "]");
            })
-                "},{dynKeys:["
-                joined(self.dyns.iter(), ",", |ctx: &Ctx, buf, (key, _, _)| {
-                    code!(buf, ctx; ctx.get_ir(*key));
+            "]),{dynKeys:["
+            joined(dyns.iter(), ",", |ctx: &Ctx, buf, (key, _, _)| {
+                code!(buf, ctx; key);
            })
            "],dynVals:["
-                joined(self.dyns.iter(), ",", |ctx: &Ctx, buf, (_, val, _)| {
-                    let val = ctx.get_ir(*val);
-                    code!(
-                        buf, ctx;
-                        "Nix.withContext(\"while evaluating a dynamic attribute\"," val.span() ",()=>(" val "))"
-                    );
+            joined(dyns.iter(), ",", |ctx: &Ctx, buf, (_, val, _)| {
+                code!(buf, ctx; val);
            })
            "],dynSpans:["
-                joined(self.dyns.iter(), ",", |ctx: &Ctx, buf, (_, _, attr_span)| {
+            joined(dyns.iter(), ",", |ctx: &Ctx, buf, (_, _, attr_span)| {
                code!(buf, ctx; attr_span);
            })
            "]})"
        );
-        } else if !self.stcs.is_empty() {
+    } else if !stcs.is_empty() {
        code!(buf, ctx;
-                "Nix.mkAttrsWithPos({"
-                joined(self.stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(expr, _))| {
+            "$ma(new Map(["
+            joined(stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(val, _))| {
                let key = ctx.get_sym(sym);
-                    let val = ctx.get_ir(expr);
-
                code!(
                    buf, ctx;
-                        key ":Nix.withContext(\"while evaluating the attribute '" escaped(&key) "'\"," val.span() ",()=>(" val "))"
+                    "[" key "," val "]"
                );
            })
-                "},{"
-                joined(self.stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(_, span))| {
-                    code!(buf, ctx; ctx.get_sym(sym) ":" span);
+            "]),new Map(["
+            joined(stcs.iter(), ",", |ctx: &Ctx, buf, (&sym, &(_, span))| {
+                code!(buf, ctx; "[" ctx.get_sym(sym) "," span "]");
            })
-                "})"
+            "]))"
        );
    } else {
-            code!(buf, ctx; "{}");
-        }
+        code!(buf, ctx; "$e");
    }
 }

-impl<Ctx: CodegenContext> Compile<Ctx> for List {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
+fn compile_list<Ctx: CodegenContext>(items: &[RawIrRef<'_>], ctx: &Ctx, buf: &mut CodeBuffer) {
    code!(buf, ctx;
        "["
-            joined(self.items.iter().enumerate(), ",", |ctx: &Ctx, buf, (idx, item)| {
-                let item = ctx.get_ir(*item);
-                code!(
-                    buf, ctx;
-                    "Nix.withContext(\"while evaluating list element " idx "\"," item.span() ",()=>(" item "))"
-                );
+            joined(items.iter(), ",", |ctx: &Ctx, buf, item| {
+                code!(buf, ctx; item);
            })
        "]"
    );
 }
-}

-impl<Ctx: CodegenContext> Compile<Ctx> for ConcatStrings {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
+fn compile_concat_strings<Ctx: CodegenContext>(
+    parts: &[RawIrRef<'_>],
+    force_string: bool,
+    ctx: &Ctx,
+    buf: &mut CodeBuffer,
+) {
    code!(buf, ctx;
-            "Nix.concatStringsWithContext(["
-            joined(self.parts.iter(), ",", |ctx: &Ctx, buf, part| {
-                let part = ctx.get_ir(*part);
-                code!(
-                    buf, ctx;
-                    "Nix.withContext(\"while evaluating a path segment\"," part.span() ",()=>(" part "))"
-                );
+        "$cs(["
+        joined(parts.iter(), ",", |ctx: &Ctx, buf, part| {
+            code!(buf, ctx; part);
        })
-            "]," self.force_string ")"
+        "]," force_string ")"
    );
 }
-}

-impl<Ctx: CodegenContext> Compile<Ctx> for HasAttr {
-    fn compile(&self, ctx: &Ctx, buf: &mut CodeBuffer) {
+fn compile_has_attr<'ir, Ctx: CodegenContext>(
+    lhs: RawIrRef<'ir>,
+    rhs: &[Attr<RawIrRef<'ir>>],
+    ctx: &Ctx,
+    buf: &mut CodeBuffer,
+) {
    code!(buf, ctx;
-            "Nix.hasAttr("
-            ctx.get_ir(self.lhs)
+        "$h("
+        lhs
        ",["
-            joined(self.rhs.iter(), ",", |ctx: &Ctx, buf, attr| {
+        joined(rhs.iter(), ",", |ctx: &Ctx, buf, attr| {
            match attr {
                Attr::Str(sym, _) => code!(buf, ctx; ctx.get_sym(*sym)),
-                    Attr::Dynamic(expr_id, _) => code!(buf, ctx; ctx.get_ir(*expr_id)),
+                Attr::Dynamic(expr, _) => code!(buf, ctx; expr),
            }
        })
        "])"
    );
 }
-}
--- a/nix-js/src/context.rs
+++ b/nix-js/src/context.rs
@@ -1,18 +1,22 @@
+use std::cell::UnsafeCell;
+use std::hash::BuildHasher;
 use std::path::Path;
-use std::ptr::NonNull;

-use hashbrown::{HashMap, HashSet};
+use bumpalo::Bump;
+use ghost_cell::{GhostCell, GhostToken};
+use hashbrown::{DefaultHashBuilder, HashMap, HashSet, HashTable};
 use rnix::TextRange;
 use string_interner::DefaultStringInterner;

-use crate::codegen::{CodegenContext, compile, compile_scoped};
+use crate::bytecode::{self, Bytecode, BytecodeContext, Constant};
+use crate::codegen::{CodegenContext, compile};
+use crate::disassembler::{Disassembler, DisassemblerContext};
 use crate::downgrade::*;
 use crate::error::{Error, Result, Source};
-use crate::ir::{
-    Arg, ArgId, Bool, Builtin, ExprId, Ir, Null, ReplBinding, ScopedImportBinding, SymId, Thunk,
-    ToIr as _, WithLookup,
-};
-use crate::runtime::{Runtime, RuntimeContext};
+use crate::ir::{ArgId, Ir, IrKey, IrRef, RawIrRef, SymId, ThunkId, ir_content_eq};
+#[cfg(feature = "inspector")]
+use crate::runtime::inspector::InspectorServer;
+use crate::runtime::{ForceMode, Runtime, RuntimeContext};
 use crate::store::{DaemonStore, Store, StoreConfig};
 use crate::value::{Symbol, Value};

@@ -47,18 +51,20 @@ fn handle_parse_error<'a>(
 pub struct Context {
    ctx: Ctx,
    runtime: Runtime<Ctx>,
+    #[cfg(feature = "inspector")]
+    _inspector_server: Option<InspectorServer>,
 }

-macro_rules! eval {
-    ($name:ident, $wrapper:literal) => {
+macro_rules! eval_bc {
+    ($name:ident, $mode:expr) => {
        pub fn $name(&mut self, source: Source) -> Result<Value> {
            tracing::info!("Starting evaluation");

-            tracing::debug!("Compiling code");
-            let code = self.compile(source)?;
+            tracing::debug!("Compiling bytecode");
+            let bytecode = self.ctx.compile_bytecode(source)?;

-            tracing::debug!("Executing JavaScript");
-            self.runtime.eval(format!($wrapper, code), &mut self.ctx)
+            tracing::debug!("Executing bytecode");
+            self.runtime.eval_bytecode(bytecode, &mut self.ctx, $mode)
        }
    };
 }
@@ -66,30 +72,76 @@ macro_rules! eval {
 impl Context {
    pub fn new() -> Result<Self> {
        let ctx = Ctx::new()?;
+        #[cfg(feature = "inspector")]
+        let runtime = Runtime::new(Default::default())?;
+        #[cfg(not(feature = "inspector"))]
        let runtime = Runtime::new()?;

-        let mut context = Self { ctx, runtime };
-        context.init_derivation()?;
+        let mut context = Self {
+            ctx,
+            runtime,
+            #[cfg(feature = "inspector")]
+            _inspector_server: None,
+        };
+        context.init()?;

        Ok(context)
    }

-    fn init_derivation(&mut self) -> Result<()> {
+    #[cfg(feature = "inspector")]
+    pub fn new_with_inspector(addr: std::net::SocketAddr, wait_for_session: bool) -> Result<Self> {
+        use crate::runtime::InspectorOptions;
+
+        let ctx = Ctx::new()?;
+        let runtime = Runtime::new(InspectorOptions {
+            enable: true,
+            wait: wait_for_session,
+        })?;
+
+        let server = crate::runtime::inspector::InspectorServer::new(addr, "nix-js")
+            .map_err(|e| Error::internal(e.to_string()))?;
+        server.register_inspector("nix-js".to_string(), runtime.inspector(), wait_for_session);
+
+        let mut context = Self {
+            ctx,
+            runtime,
+            _inspector_server: Some(server),
+        };
+        context.init()?;
+        Ok(context)
+    }
+
+    #[cfg(feature = "inspector")]
+    pub fn wait_for_inspector_disconnect(&mut self) {
+        self.runtime.wait_for_inspector_disconnect();
+    }
+
+    fn init(&mut self) -> Result<()> {
        const DERIVATION_NIX: &str = include_str!("runtime/corepkgs/derivation.nix");
        let source = Source::new_virtual(
            "<nix/derivation-internal.nix>".into(),
            DERIVATION_NIX.to_string(),
        );
        let code = self.ctx.compile(source, None)?;
-        self.runtime
-            .eval(format!("Nix.builtins.derivation = {}", code), &mut self.ctx)?;
+        self.runtime.eval(
+            format!(
+                "Nix.builtins.set('derivation',({}));Nix.builtins.set('storeDir','{}');{}0n",
+                code,
+                self.get_store_dir(),
+                if std::env::var("NIX_JS_DEBUG_THUNKS").is_ok() {
+                    "Nix.DEBUG_THUNKS.enabled=true;"
+                } else {
+                    ""
+                }
+            ),
+            &mut self.ctx,
+        )?;
        Ok(())
    }

-    eval!(eval, "Nix.force({})");
-    eval!(eval_shallow, "Nix.forceShallow({})");
-    eval!(eval_deep, "Nix.forceDeep({})");
-
+    eval_bc!(eval, ForceMode::Force);
+    eval_bc!(eval_shallow, ForceMode::ForceShallow);
+    eval_bc!(eval_deep, ForceMode::ForceDeep);
    pub fn eval_repl<'a>(&'a mut self, source: Source, scope: &'a HashSet<SymId>) -> Result<Value> {
        tracing::info!("Starting evaluation");

@@ -105,6 +157,18 @@ impl Context {
        self.ctx.compile(source, None)
    }

+    pub fn compile_bytecode(&mut self, source: Source) -> Result<Bytecode> {
+        self.ctx.compile_bytecode(source)
+    }
+
+    pub fn disassemble(&self, bytecode: &Bytecode) -> String {
+        Disassembler::new(bytecode, &self.ctx).disassemble()
+    }
+
+    pub fn disassemble_colored(&self, bytecode: &Bytecode) -> String {
+        Disassembler::new(bytecode, &self.ctx).disassemble_colored()
+    }
+
    pub fn get_store_dir(&self) -> &str {
        self.ctx.get_store_dir()
    }
@@ -130,32 +194,44 @@ impl Context {
    }
 }

-pub(crate) struct Ctx {
-    irs: Vec<Ir>,
+struct Ctx {
    symbols: DefaultStringInterner,
-    global: NonNull<HashMap<SymId, ExprId>>,
+    global: HashMap<SymId, Ir<'static, RawIrRef<'static>>>,
    sources: Vec<Source>,
    store: DaemonStore,
+    spans: UnsafeCell<Vec<(usize, TextRange)>>,
+    thunk_count: usize,
+    global_strings: Vec<String>,
+    global_string_map: HashMap<String, u32>,
+    global_constants: Vec<Constant>,
+    global_constant_map: HashMap<Constant, u32>,
+    synced_strings: usize,
+    synced_constants: usize,
+}
+
+/// Owns the bump allocator and a read-only reference into it.
+///
+/// # Safety
+/// The `ir` field points into `_bump`'s storage. We use `'static` as a sentinel
+/// lifetime because the struct owns the backing memory. The `as_ref` method
+/// re-binds the lifetime to `&self`, preventing use-after-free.
+struct OwnedIr {
+    _bump: Bump,
+    ir: RawIrRef<'static>,
+}
+
+impl OwnedIr {
+    fn as_ref(&self) -> RawIrRef<'_> {
+        self.ir
+    }
 }

 impl Ctx {
    fn new() -> Result<Self> {
-        use crate::ir::{Builtins, ToIr as _};
-
        let mut symbols = DefaultStringInterner::new();
-        let mut irs = Vec::new();
        let mut global = HashMap::new();
-
-        irs.push(
-            Builtins {
-                span: rnix::TextRange::default(),
-            }
-            .to_ir(),
-        );
-        let builtins_expr = ExprId(0);
-
        let builtins_sym = symbols.get_or_intern("builtins");
-        global.insert(builtins_sym, builtins_expr);
+        global.insert(builtins_sym, Ir::Builtins);

        let free_globals = [
            "abort",
@@ -179,48 +255,19 @@ impl Ctx {
            "toString",
        ];
        let consts = [
-            (
-                "true",
-                Bool {
-                    inner: true,
-                    span: rnix::TextRange::default(),
-                }
-                .to_ir(),
-            ),
-            (
-                "false",
-                Bool {
-                    inner: false,
-                    span: rnix::TextRange::default(),
-                }
-                .to_ir(),
-            ),
-            (
-                "null",
-                Null {
-                    span: rnix::TextRange::default(),
-                }
-                .to_ir(),
-            ),
+            ("true", Ir::Bool(true)),
+            ("false", Ir::Bool(false)),
+            ("null", Ir::Null),
        ];

        for name in free_globals {
-            let name_sym = symbols.get_or_intern(name);
-            let id = ExprId(irs.len());
-            irs.push(
-                Builtin {
-                    inner: name_sym,
-                    span: rnix::TextRange::default(),
-                }
-                .to_ir(),
-            );
-            global.insert(name_sym, id);
+            let name = symbols.get_or_intern(name);
+            let value = Ir::Builtin(name);
+            global.insert(name, value);
        }
        for (name, value) in consts {
-            let name_sym = symbols.get_or_intern(name);
-            let id = ExprId(irs.len());
-            irs.push(value);
-            global.insert(name_sym, id);
+            let name = symbols.get_or_intern(name);
+            global.insert(name, value);
        }

        let config = StoreConfig::from_env();
@@ -228,19 +275,39 @@ impl Ctx {

        Ok(Self {
            symbols,
-            irs,
-            global: unsafe { NonNull::new_unchecked(Box::leak(Box::new(global))) },
+            global,
            sources: Vec::new(),
            store,
+            spans: UnsafeCell::new(Vec::new()),
+            thunk_count: 0,
+            global_strings: Vec::new(),
+            global_string_map: HashMap::new(),
+            global_constants: Vec::new(),
+            global_constant_map: HashMap::new(),
+            synced_strings: 0,
+            synced_constants: 0,
        })
    }

-    fn downgrade_ctx<'a>(&'a mut self, extra_scope: Option<Scope<'a>>) -> DowngradeCtx<'a> {
-        let global_ref = unsafe { self.global.as_ref() };
-        DowngradeCtx::new(self, global_ref, extra_scope)
+    fn downgrade_ctx<'ctx, 'id, 'ir>(
+        &'ctx mut self,
+        bump: &'ir Bump,
+        token: GhostToken<'id>,
+        extra_scope: Option<Scope<'ctx>>,
+    ) -> DowngradeCtx<'ctx, 'id, 'ir> {
+        let source = self.get_current_source();
+        DowngradeCtx::new(
+            bump,
+            token,
+            &mut self.symbols,
+            &self.global,
+            extra_scope,
+            &mut self.thunk_count,
+            source,
+        )
    }

-    pub(crate) fn get_current_dir(&self) -> &Path {
+    fn get_current_dir(&self) -> &Path {
        self.sources
            .last()
            .as_ref()
@@ -248,18 +315,18 @@ impl Ctx {
            .get_dir()
    }

-    pub(crate) fn get_current_source(&self) -> Source {
+    fn get_current_source(&self) -> Source {
        self.sources
            .last()
            .expect("current_source is not set")
            .clone()
    }

-    pub(crate) fn get_source(&self, id: usize) -> Source {
-        self.sources.get(id).expect("source not found").clone()
-    }
-
-    fn downgrade<'a>(&mut self, source: Source, extra_scope: Option<Scope<'a>>) -> Result<ExprId> {
+    fn downgrade<'ctx>(
+        &'ctx mut self,
+        source: Source,
+        extra_scope: Option<Scope<'ctx>>,
+    ) -> Result<OwnedIr> {
        tracing::debug!("Parsing Nix expression");

        self.sources.push(source.clone());
@@ -272,18 +339,29 @@ impl Ctx {
            .tree()
            .expr()
            .ok_or_else(|| Error::parse_error("unexpected EOF".into()))?;
-        self.downgrade_ctx(extra_scope).downgrade(expr)
+        let bump = Bump::new();
+        GhostToken::new(|token| {
+            let ir = self
+                .downgrade_ctx(&bump, token, extra_scope)
+                .downgrade_toplevel(expr)?;
+            let ir = unsafe { std::mem::transmute::<RawIrRef<'_>, RawIrRef<'static>>(ir) };
+            Ok(OwnedIr { _bump: bump, ir })
+        })
    }

-    fn compile<'a>(&'a mut self, source: Source, extra_scope: Option<Scope<'a>>) -> Result<String> {
+    fn compile<'ctx>(
+        &'ctx mut self,
+        source: Source,
+        extra_scope: Option<Scope<'ctx>>,
+    ) -> Result<String> {
        let root = self.downgrade(source, extra_scope)?;
        tracing::debug!("Generating JavaScript code");
-        let code = compile(self.get_ir(root), self);
+        let code = compile::<false>(root.as_ref(), self);
        tracing::debug!("Generated code: {}", &code);
        Ok(code)
    }

-    pub(crate) fn compile_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<String> {
+    fn compile_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<String> {
        let scope = Scope::ScopedImport(
            scope
                .into_iter()
@@ -292,16 +370,33 @@ impl Ctx {
        );
        let root = self.downgrade(source, Some(scope))?;
        tracing::debug!("Generating JavaScript code for scoped import");
-        let code = compile_scoped(self.get_ir(root), self);
+        let code = compile::<true>(root.as_ref(), self);
        tracing::debug!("Generated scoped code: {}", &code);
        Ok(code)
    }
+
+    fn compile_bytecode(&mut self, source: Source) -> Result<Bytecode> {
+        let root = self.downgrade(source, None)?;
+        tracing::debug!("Generating bytecode");
+        let bytecode = bytecode::compile_bytecode(root.as_ref(), self);
+        tracing::debug!("Compiled bytecode: {:#04X?}", bytecode.code);
+        Ok(bytecode)
+    }
+
+    fn compile_bytecode_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<Bytecode> {
+        let scope = Scope::ScopedImport(
+            scope
+                .into_iter()
+                .map(|k| self.symbols.get_or_intern(k))
+                .collect(),
+        );
+        let root = self.downgrade(source, Some(scope))?;
+        tracing::debug!("Generating bytecode for scoped import");
+        Ok(bytecode::compile_bytecode_scoped(root.as_ref(), self))
+    }
 }

 impl CodegenContext for Ctx {
-    fn get_ir(&self, id: ExprId) -> &Ir {
-        self.irs.get(id.0).expect("ExprId out of bounds")
-    }
    fn get_sym(&self, id: SymId) -> Symbol<'_> {
        self.symbols
            .resolve(id)
@@ -317,12 +412,49 @@ impl CodegenContext for Ctx {
            .checked_sub(1)
            .expect("current_source not set")
    }
-    fn get_current_source(&self) -> crate::error::Source {
-        self.sources.last().expect("current_source not set").clone()
-    }
    fn get_store_dir(&self) -> &str {
        self.store.get_store_dir()
    }
+    fn register_span(&self, range: rnix::TextRange) -> usize {
+        let spans = unsafe { &mut *self.spans.get() };
+        let id = spans.len();
+        spans.push((self.get_current_source_id(), range));
+        id
+    }
+}
+
+impl BytecodeContext for Ctx {
+    fn intern_string(&mut self, s: &str) -> u32 {
+        if let Some(&idx) = self.global_string_map.get(s) {
+            return idx;
+        }
+        let idx = self.global_strings.len() as u32;
+        self.global_strings.push(s.to_string());
+        self.global_string_map.insert(s.to_string(), idx);
+        idx
+    }
+
+    fn intern_constant(&mut self, c: Constant) -> u32 {
+        if let Some(&idx) = self.global_constant_map.get(&c) {
+            return idx;
+        }
+        let idx = self.global_constants.len() as u32;
+        self.global_constants.push(c.clone());
+        self.global_constant_map.insert(c, idx);
+        idx
+    }
+
+    fn register_span(&self, range: TextRange) -> u32 {
+        CodegenContext::register_span(self, range) as u32
+    }
+
+    fn get_sym(&self, id: SymId) -> &str {
+        self.symbols.resolve(id).expect("SymId out of bounds")
+    }
+
+    fn get_current_dir(&self) -> &Path {
+        Ctx::get_current_dir(self)
+    }
 }

 impl RuntimeContext for Ctx {
@@ -338,156 +470,239 @@ impl RuntimeContext for Ctx {
    fn compile_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<String> {
        self.compile_scoped(source, scope)
    }
+    fn compile_bytecode(&mut self, source: Source) -> Result<Bytecode> {
+        self.compile_bytecode(source)
+    }
+    fn compile_bytecode_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<Bytecode> {
+        self.compile_bytecode_scoped(source, scope)
+    }
    fn get_source(&self, id: usize) -> Source {
-        self.get_source(id)
+        self.sources.get(id).expect("source not found").clone()
    }
    fn get_store(&self) -> &DaemonStore {
        &self.store
    }
+    fn get_span(&self, id: usize) -> (usize, TextRange) {
+        let spans = unsafe { &*self.spans.get() };
+        spans[id]
+    }
+    fn get_unsynced(&mut self) -> (&[String], &[Constant], usize, usize) {
+        let strings_base = self.synced_strings;
+        let constants_base = self.synced_constants;
+        let new_strings = &self.global_strings[strings_base..];
+        let new_constants = &self.global_constants[constants_base..];
+        self.synced_strings = self.global_strings.len();
+        self.synced_constants = self.global_constants.len();
+        (new_strings, new_constants, strings_base, constants_base)
+    }
+}
+
+impl DisassemblerContext for Ctx {
+    fn lookup_string(&self, id: u32) -> &str {
+        self.global_strings
+            .get(id as usize)
+            .expect("string not found")
+    }
+    fn lookup_constant(&self, id: u32) -> &Constant {
+        self.global_constants
+            .get(id as usize)
+            .expect("constant not found")
+    }
 }

 enum Scope<'ctx> {
-    Global(&'ctx HashMap<SymId, ExprId>),
+    Global(&'ctx HashMap<SymId, Ir<'static, RawIrRef<'static>>>),
    Repl(&'ctx HashSet<SymId>),
    ScopedImport(HashSet<SymId>),
-    Let(HashMap<SymId, ExprId>),
-    Param(SymId, ExprId),
+    Let(HashMap<SymId, ThunkId>),
+    Param(SymId, ArgId),
 }

-struct ScopeGuard<'a, 'ctx> {
-    ctx: &'a mut DowngradeCtx<'ctx>,
+struct ScopeGuard<'a, 'ctx, 'id, 'ir> {
+    ctx: &'a mut DowngradeCtx<'ctx, 'id, 'ir>,
 }

-impl<'a, 'ctx> Drop for ScopeGuard<'a, 'ctx> {
+impl Drop for ScopeGuard<'_, '_, '_, '_> {
    fn drop(&mut self) {
        self.ctx.scopes.pop();
    }
 }

-impl<'a, 'ctx> ScopeGuard<'a, 'ctx> {
-    fn as_ctx(&mut self) -> &mut DowngradeCtx<'ctx> {
+impl<'id, 'ir, 'ctx> ScopeGuard<'_, 'ctx, 'id, 'ir> {
+    fn as_ctx(&mut self) -> &mut DowngradeCtx<'ctx, 'id, 'ir> {
        self.ctx
    }
 }

-pub struct DowngradeCtx<'ctx> {
-    ctx: &'ctx mut Ctx,
-    irs: Vec<Ir>,
+struct ThunkScope<'id, 'ir> {
+    bindings: bumpalo::collections::Vec<'ir, (ThunkId, IrRef<'id, 'ir>)>,
+    cache: HashTable<(IrRef<'id, 'ir>, ThunkId)>,
+    hasher: DefaultHashBuilder,
+}
+
+impl<'id, 'ir> ThunkScope<'id, 'ir> {
+    fn new_in(bump: &'ir Bump) -> Self {
+        Self {
+            bindings: bumpalo::collections::Vec::new_in(bump),
+            cache: HashTable::new(),
+            hasher: DefaultHashBuilder::default(),
+        }
+    }
+
+    fn lookup_cache(&self, key: IrRef<'id, 'ir>, token: &GhostToken<'id>) -> Option<ThunkId> {
+        let hash = self.hasher.hash_one(IrKey(key, token));
+        self.cache
+            .find(hash, |&(ir, _)| ir_content_eq(key, ir, token))
+            .map(|&(_, id)| id)
+    }
+
+    fn add_binding(&mut self, id: ThunkId, ir: IrRef<'id, 'ir>, token: &GhostToken<'id>) {
+        self.bindings.push((id, ir));
+        let hash = self.hasher.hash_one(IrKey(ir, token));
+        self.cache.insert_unique(hash, (ir, id), |&(ir, _)| {
+            self.hasher.hash_one(IrKey(ir, token))
+        });
+    }
+
+    fn extend_bindings(&mut self, iter: impl IntoIterator<Item = (ThunkId, IrRef<'id, 'ir>)>) {
+        self.bindings.extend(iter);
+    }
+}
+
+struct DowngradeCtx<'ctx, 'id, 'ir> {
+    bump: &'ir Bump,
+    token: GhostToken<'id>,
+    symbols: &'ctx mut DefaultStringInterner,
+    source: Source,
    scopes: Vec<Scope<'ctx>>,
    with_scope_count: usize,
-    arg_id: usize,
-    thunk_scopes: Vec<Vec<(ExprId, ExprId)>>,
+    arg_count: usize,
+    thunk_count: &'ctx mut usize,
+    thunk_scopes: Vec<ThunkScope<'id, 'ir>>,
 }

-impl<'ctx> DowngradeCtx<'ctx> {
-    fn new(
-        ctx: &'ctx mut Ctx,
-        global: &'ctx HashMap<SymId, ExprId>,
-        extra_scope: Option<Scope<'ctx>>,
-    ) -> Self {
-        Self {
-            scopes: std::iter::once(Scope::Global(global))
-                .chain(extra_scope)
-                .collect(),
-            irs: vec![],
-            arg_id: 0,
-            with_scope_count: 0,
-            thunk_scopes: vec![Vec::new()],
-            ctx,
-        }
-    }
-}
-
-impl DowngradeContext for DowngradeCtx<'_> {
-    fn new_expr(&mut self, expr: Ir) -> ExprId {
-        self.irs.push(expr);
-        ExprId(self.ctx.irs.len() + self.irs.len() - 1)
-    }
-
-    fn new_arg(&mut self, span: TextRange) -> ExprId {
-        self.irs.push(
-            Arg {
-                inner: ArgId(self.arg_id),
-                span,
-            }
-            .to_ir(),
-        );
-        self.arg_id += 1;
-        ExprId(self.ctx.irs.len() + self.irs.len() - 1)
-    }
-
-    fn get_ir(&self, id: ExprId) -> &Ir {
-        if id.0 < self.ctx.irs.len() {
-            self.ctx.irs.get(id.0).expect("unreachable")
-        } else {
-            self.irs
-                .get(id.0 - self.ctx.irs.len())
-                .expect("ExprId out of bounds")
-        }
-    }
-
-    fn maybe_thunk(&mut self, id: ExprId) -> ExprId {
-        let ir = self.get_ir(id);
-        match ir {
+fn should_thunk<'id>(ir: IrRef<'id, '_>, token: &GhostToken<'id>) -> bool {
+    !matches!(
+        ir.borrow(token),
        Ir::Builtin(_)
-            | Ir::Builtins(_)
+            | Ir::Builtins
            | Ir::Int(_)
            | Ir::Float(_)
            | Ir::Bool(_)
-            | Ir::Null(_)
+            | Ir::Null
            | Ir::Str(_)
-            | Ir::Thunk(_) => id,
-            _ => {
-                let span = ir.span();
-                let slot = self.reserve_slots(1).next().expect("reserve_slots failed");
-                self.replace_ir(slot, Thunk { inner: slot, span }.to_ir());
-                self.register_thunk(slot, id);
-                slot
+            | Ir::Thunk(_)
+    )
+}
+
+impl<'ctx, 'id, 'ir> DowngradeCtx<'ctx, 'id, 'ir> {
+    fn new(
+        bump: &'ir Bump,
+        token: GhostToken<'id>,
+        symbols: &'ctx mut DefaultStringInterner,
+        global: &'ctx HashMap<SymId, Ir<'static, RawIrRef<'static>>>,
+        extra_scope: Option<Scope<'ctx>>,
+        thunk_count: &'ctx mut usize,
+        source: Source,
+    ) -> Self {
+        Self {
+            bump,
+            token,
+            symbols,
+            source,
+            scopes: std::iter::once(Scope::Global(global))
+                .chain(extra_scope)
+                .collect(),
+            thunk_count,
+            arg_count: 0,
+            with_scope_count: 0,
+            thunk_scopes: vec![ThunkScope::new_in(bump)],
        }
    }
 }

+impl<'ctx: 'ir, 'id, 'ir> DowngradeContext<'id, 'ir> for DowngradeCtx<'ctx, 'id, 'ir> {
+    fn new_expr(&self, expr: Ir<'ir, IrRef<'id, 'ir>>) -> IrRef<'id, 'ir> {
+        IrRef::new(self.bump.alloc(GhostCell::new(expr)))
+    }
+
+    fn new_arg(&mut self) -> ArgId {
+        self.arg_count += 1;
+        ArgId(self.arg_count - 1)
+    }
+
+    fn maybe_thunk(&mut self, ir: IrRef<'id, 'ir>) -> IrRef<'id, 'ir> {
+        if !should_thunk(ir, &self.token) {
+            return ir;
+        }
+
+        let cached = self
+            .thunk_scopes
+            .last()
+            .expect("no active cache scope")
+            .lookup_cache(ir, &self.token);
+
+        if let Some(id) = cached {
+            return IrRef::alloc(self.bump, Ir::Thunk(id));
+        }
+
+        let id = ThunkId(*self.thunk_count);
+        *self.thunk_count = self.thunk_count.checked_add(1).expect("thunk id overflow");
+        self.thunk_scopes
+            .last_mut()
+            .expect("no active cache scope")
+            .add_binding(id, ir, &self.token);
+        IrRef::alloc(self.bump, Ir::Thunk(id))
+    }
+
    fn new_sym(&mut self, sym: String) -> SymId {
-        self.ctx.symbols.get_or_intern(sym)
+        self.symbols.get_or_intern(sym)
    }

    fn get_sym(&self, id: SymId) -> Symbol<'_> {
-        self.ctx.get_sym(id)
+        self.symbols.resolve(id).expect("no symbol found").into()
    }

-    fn lookup(&mut self, sym: SymId, span: TextRange) -> Result<ExprId> {
+    fn lookup(&self, sym: SymId, span: TextRange) -> Result<IrRef<'id, 'ir>> {
        for scope in self.scopes.iter().rev() {
            match scope {
                &Scope::Global(global_scope) => {
-                    if let Some(&expr) = global_scope.get(&sym) {
-                        return Ok(expr);
+                    if let Some(expr) = global_scope.get(&sym) {
+                        let ir = match expr {
+                            Ir::Builtins => Ir::Builtins,
+                            Ir::Builtin(s) => Ir::Builtin(*s),
+                            Ir::Bool(b) => Ir::Bool(*b),
+                            Ir::Null => Ir::Null,
+                            _ => unreachable!("globals should only contain leaf IR nodes"),
+                        };
+                        return Ok(self.new_expr(ir));
                    }
                }
                &Scope::Repl(repl_bindings) => {
                    if repl_bindings.contains(&sym) {
-                        return Ok(self.new_expr(ReplBinding { inner: sym, span }.to_ir()));
+                        return Ok(self.new_expr(Ir::ReplBinding(sym)));
                    }
                }
                Scope::ScopedImport(scoped_bindings) => {
                    if scoped_bindings.contains(&sym) {
-                        return Ok(self.new_expr(ScopedImportBinding { inner: sym, span }.to_ir()));
+                        return Ok(self.new_expr(Ir::ScopedImportBinding(sym)));
                    }
                }
                Scope::Let(let_scope) => {
                    if let Some(&expr) = let_scope.get(&sym) {
-                        return Ok(self.new_expr(Thunk { inner: expr, span }.to_ir()));
+                        return Ok(self.new_expr(Ir::Thunk(expr)));
                    }
                }
-                &Scope::Param(param_sym, expr) => {
+                &Scope::Param(param_sym, id) => {
                    if param_sym == sym {
-                        return Ok(expr);
+                        return Ok(self.new_expr(Ir::Arg(id)));
                    }
                }
            }
        }

        if self.with_scope_count > 0 {
-            Ok(self.new_expr(WithLookup { inner: sym, span }.to_ir()))
+            Ok(self.new_expr(Ir::WithLookup(sym)))
        } else {
            Err(Error::downgrade_error(
                format!("'{}' not found", self.get_sym(sym)),
@@ -497,49 +712,37 @@ impl DowngradeContext for DowngradeCtx<'_> {
        }
    }

-    fn replace_ir(&mut self, id: ExprId, expr: Ir) {
-        let local_id = id.0 - self.ctx.irs.len();
-        *self.irs.get_mut(local_id).expect("ExprId out of bounds") = expr;
-    }
-
    fn get_current_source(&self) -> Source {
-        self.ctx.get_current_source()
+        self.source.clone()
    }

-    #[allow(refining_impl_trait)]
-    fn reserve_slots(&mut self, slots: usize) -> impl Iterator<Item = ExprId> + Clone + use<> {
-        let start = self.ctx.irs.len() + self.irs.len();
-        let range = (start..start + slots).map(ExprId);
-        let span = rnix::TextRange::default();
-        // Fill reserved slots with placeholder value
-        self.irs.extend(
-            range
-                .clone()
-                .map(|slot| Thunk { inner: slot, span }.to_ir()),
-        );
-        range
-    }
-
-    fn downgrade(mut self, root: rnix::ast::Expr) -> Result<ExprId> {
-        use crate::ir::TopLevel;
-        let body = root.downgrade(&mut self)?;
-        let thunks = self.thunk_scopes.pop().expect("no thunk scope left???");
-        let span = self.get_ir(body).span();
-        let top_level = self.new_expr(TopLevel { body, thunks, span }.to_ir());
-        self.ctx.irs.extend(self.irs);
-        Ok(top_level)
-    }
-
-    fn with_let_scope<F, R>(&mut self, bindings: HashMap<SymId, ExprId>, f: F) -> R
+    fn with_let_scope<F, R>(&mut self, keys: &[SymId], f: F) -> Result<R>
    where
-        F: FnOnce(&mut Self) -> R,
+        F: FnOnce(&mut Self) -> Result<(bumpalo::collections::Vec<'ir, IrRef<'id, 'ir>>, R)>,
    {
-        self.scopes.push(Scope::Let(bindings));
+        let base = *self.thunk_count;
+        *self.thunk_count = self
+            .thunk_count
+            .checked_add(keys.len())
+            .expect("thunk id overflow");
+        let iter = keys.iter().enumerate().map(|(offset, &key)| {
+            (
+                key,
+                ThunkId(unsafe { base.checked_add(offset).unwrap_unchecked() }),
+            )
+        });
+        self.scopes.push(Scope::Let(iter.collect()));
+        let (vals, ret) = {
            let mut guard = ScopeGuard { ctx: self };
-        f(guard.as_ctx())
+            f(guard.as_ctx())?
+        };
+        assert_eq!(keys.len(), vals.len());
+        let scope = self.thunk_scopes.last_mut().expect("no active thunk scope");
+        scope.extend_bindings((base..base + keys.len()).map(ThunkId).zip(vals));
+        Ok(ret)
    }

-    fn with_param_scope<F, R>(&mut self, param: SymId, arg: ExprId, f: F) -> R
+    fn with_param_scope<F, R>(&mut self, param: SymId, arg: ArgId, f: F) -> R
    where
        F: FnOnce(&mut Self) -> R,
    {
@@ -558,22 +761,41 @@ impl DowngradeContext for DowngradeCtx<'_> {
        ret
    }

-    fn with_thunk_scope<F, R>(&mut self, f: F) -> (R, Vec<(ExprId, ExprId)>)
+    fn with_thunk_scope<F, R>(
+        &mut self,
+        f: F,
+    ) -> (
+        R,
+        bumpalo::collections::Vec<'ir, (ThunkId, IrRef<'id, 'ir>)>,
+    )
    where
        F: FnOnce(&mut Self) -> R,
    {
-        self.thunk_scopes.push(Vec::new());
+        self.thunk_scopes.push(ThunkScope::new_in(self.bump));
        let ret = f(self);
        (
            ret,
-            self.thunk_scopes.pop().expect("no thunk scope left???"),
+            self.thunk_scopes
+                .pop()
+                .expect("no thunk scope left???")
+                .bindings,
        )
    }

-    fn register_thunk(&mut self, slot: ExprId, inner: ExprId) {
-        self.thunk_scopes
-            .last_mut()
-            .expect("register_thunk without active scope")
-            .push((slot, inner));
+    fn bump(&self) -> &'ir bumpalo::Bump {
+        self.bump
+    }
+}
+
+impl<'id, 'ir, 'ctx: 'ir> DowngradeCtx<'ctx, 'id, 'ir> {
+    fn downgrade_toplevel(mut self, root: rnix::ast::Expr) -> Result<RawIrRef<'ir>> {
+        let body = root.downgrade(&mut self)?;
+        let thunks = self
+            .thunk_scopes
+            .pop()
+            .expect("no thunk scope left???")
+            .bindings;
+        let ir = IrRef::alloc(self.bump, Ir::TopLevel { body, thunks });
+        Ok(ir.freeze(self.token))
    }
 }
--- a/nix-js/src/derivation.rs
+++ b/nix-js/src/derivation.rs
@@ -0,0 +1,142 @@
+use std::collections::{BTreeMap, BTreeSet};
+
+pub struct OutputInfo {
+    pub path: String,
+    pub hash_algo: String,
+    pub hash: String,
+}
+
+pub struct DerivationData {
+    pub name: String,
+    pub outputs: BTreeMap<String, OutputInfo>,
+    pub input_drvs: BTreeMap<String, BTreeSet<String>>,
+    pub input_srcs: BTreeSet<String>,
+    pub platform: String,
+    pub builder: String,
+    pub args: Vec<String>,
+    pub env: BTreeMap<String, String>,
+}
+
+fn escape_string(s: &str) -> String {
+    let mut result = String::with_capacity(s.len() + 2);
+    result.push('"');
+    for c in s.chars() {
+        match c {
+            '"' => result.push_str("\\\""),
+            '\\' => result.push_str("\\\\"),
+            '\n' => result.push_str("\\n"),
+            '\r' => result.push_str("\\r"),
+            '\t' => result.push_str("\\t"),
+            _ => result.push(c),
+        }
+    }
+    result.push('"');
+    result
+}
+
+fn quote_string(s: &str) -> String {
+    format!("\"{}\"", s)
+}
+
+impl DerivationData {
+    pub fn generate_aterm(&self) -> String {
+        let mut output_entries = Vec::new();
+        for (name, info) in &self.outputs {
+            output_entries.push(format!(
+                "({},{},{},{})",
+                quote_string(name),
+                quote_string(&info.path),
+                quote_string(&info.hash_algo),
+                quote_string(&info.hash),
+            ));
+        }
+        let outputs = output_entries.join(",");
+
+        let mut input_drv_entries = Vec::new();
+        for (drv_path, output_names) in &self.input_drvs {
+            let sorted_outs: Vec<String> = output_names.iter().map(|s| quote_string(s)).collect();
+            let out_list = format!("[{}]", sorted_outs.join(","));
+            input_drv_entries.push(format!("({},{})", quote_string(drv_path), out_list));
+        }
+        let input_drvs = input_drv_entries.join(",");
+
+        let input_srcs: Vec<String> = self.input_srcs.iter().map(|s| quote_string(s)).collect();
+        let input_srcs = input_srcs.join(",");
+
+        let args: Vec<String> = self.args.iter().map(|s| escape_string(s)).collect();
+        let args = args.join(",");
+
+        let mut env_entries: Vec<String> = Vec::new();
+        for (k, v) in &self.env {
+            env_entries.push(format!("({},{})", escape_string(k), escape_string(v)));
+        }
+
+        format!(
+            "Derive([{}],[{}],[{}],{},{},[{}],[{}])",
+            outputs,
+            input_drvs,
+            input_srcs,
+            quote_string(&self.platform),
+            escape_string(&self.builder),
+            args,
+            env_entries.join(","),
+        )
+    }
+
+    pub fn generate_aterm_modulo(&self, input_drv_hashes: &BTreeMap<String, String>) -> String {
+        let mut output_entries = Vec::new();
+        for (name, info) in &self.outputs {
+            output_entries.push(format!(
+                "({},{},{},{})",
+                quote_string(name),
+                quote_string(&info.path),
+                quote_string(&info.hash_algo),
+                quote_string(&info.hash),
+            ));
+        }
+        let outputs = output_entries.join(",");
+
+        let mut input_drv_entries = Vec::new();
+        for (drv_hash, outputs_csv) in input_drv_hashes {
+            let mut sorted_outs: Vec<&str> = outputs_csv.split(',').collect();
+            sorted_outs.sort();
+            let out_list: Vec<String> = sorted_outs.iter().map(|s| quote_string(s)).collect();
+            let out_list = format!("[{}]", out_list.join(","));
+            input_drv_entries.push(format!("({},{})", quote_string(drv_hash), out_list));
+        }
+        let input_drvs = input_drv_entries.join(",");
+
+        let input_srcs: Vec<String> = self.input_srcs.iter().map(|s| quote_string(s)).collect();
+        let input_srcs = input_srcs.join(",");
+
+        let args: Vec<String> = self.args.iter().map(|s| escape_string(s)).collect();
+        let args = args.join(",");
+
+        let mut env_entries: Vec<String> = Vec::new();
+        for (k, v) in &self.env {
+            env_entries.push(format!("({},{})", escape_string(k), escape_string(v)));
+        }
+
+        format!(
+            "Derive([{}],[{}],[{}],{},{},[{}],[{}])",
+            outputs,
+            input_drvs,
+            input_srcs,
+            quote_string(&self.platform),
+            escape_string(&self.builder),
+            args,
+            env_entries.join(","),
+        )
+    }
+
+    pub fn collect_references(&self) -> Vec<String> {
+        let mut refs = BTreeSet::new();
+        for src in &self.input_srcs {
+            refs.insert(src.clone());
+        }
+        for drv_path in self.input_drvs.keys() {
+            refs.insert(drv_path.clone());
+        }
+        refs.into_iter().collect()
+    }
+}
--- a/nix-js/src/disassembler.rs
+++ b/nix-js/src/disassembler.rs
@@ -0,0 +1,354 @@
+use std::fmt::Write;
+
+use colored::Colorize;
+use num_enum::TryFromPrimitive;
+
+use crate::bytecode::{Bytecode, Constant, Op};
+
+pub(crate) trait DisassemblerContext {
+    fn lookup_string(&self, id: u32) -> &str;
+    fn lookup_constant(&self, id: u32) -> &Constant;
+}
+
+pub(crate) struct Disassembler<'a, Ctx> {
+    code: &'a [u8],
+    ctx: &'a Ctx,
+    pos: usize,
+}
+
+impl<'a, Ctx: DisassemblerContext> Disassembler<'a, Ctx> {
+    pub fn new(bytecode: &'a Bytecode, ctx: &'a Ctx) -> Self {
+        Self {
+            code: &bytecode.code,
+            ctx,
+            pos: 0,
+        }
+    }
+
+    fn read_u8(&mut self) -> u8 {
+        let b = self.code[self.pos];
+        self.pos += 1;
+        b
+    }
+
+    fn read_u16(&mut self) -> u16 {
+        let bytes = self.code[self.pos..self.pos + 2]
+            .try_into()
+            .expect("no enough bytes");
+        self.pos += 2;
+        u16::from_le_bytes(bytes)
+    }
+
+    fn read_u32(&mut self) -> u32 {
+        let bytes = self.code[self.pos..self.pos + 4]
+            .try_into()
+            .expect("no enough bytes");
+        self.pos += 4;
+        u32::from_le_bytes(bytes)
+    }
+
+    fn read_i32(&mut self) -> i32 {
+        let bytes = self.code[self.pos..self.pos + 4]
+            .try_into()
+            .expect("no enough bytes");
+        self.pos += 4;
+        i32::from_le_bytes(bytes)
+    }
+
+    pub fn disassemble(&mut self) -> String {
+        self.disassemble_impl(false)
+    }
+
+    pub fn disassemble_colored(&mut self) -> String {
+        self.disassemble_impl(true)
+    }
+
+    fn disassemble_impl(&mut self, color: bool) -> String {
+        let mut out = String::new();
+        if color {
+            let _ = writeln!(out, "{}", "=== Bytecode Disassembly ===".bold().white());
+            let _ = writeln!(
+                out,
+                "{} {}",
+                "Length:".white(),
+                format!("{} bytes", self.code.len()).cyan()
+            );
+        } else {
+            let _ = writeln!(out, "=== Bytecode Disassembly ===");
+            let _ = writeln!(out, "Length: {} bytes", self.code.len());
+        }
+
+        while self.pos < self.code.len() {
+            let start_pos = self.pos;
+            let op_byte = self.read_u8();
+            let (mnemonic, args) = self.decode_instruction(op_byte, start_pos);
+
+            let bytes_slice = &self.code[start_pos + 1..self.pos];
+
+            for (i, chunk) in bytes_slice.chunks(4).enumerate() {
+                let bytes_str = {
+                    let mut temp = String::new();
+                    if i == 0 {
+                        let _ = write!(&mut temp, "{:02x}", self.code[start_pos]);
+                    } else {
+                        let _ = write!(&mut temp, "  ");
+                    }
+                    for b in chunk.iter() {
+                        let _ = write!(&mut temp, " {:02x}", b);
+                    }
+                    temp
+                };
+
+                if i == 0 {
+                    if color {
+                        let sep = if args.is_empty() { "" } else { " " };
+                        let _ = writeln!(
+                            out,
+                            "{}  {:<14} | {}{}{}",
+                            format!("{:04x}", start_pos).dimmed(),
+                            bytes_str.green(),
+                            mnemonic.yellow().bold(),
+                            sep,
+                            args.cyan()
+                        );
+                    } else {
+                        let op_str = if args.is_empty() {
+                            mnemonic.to_string()
+                        } else {
+                            format!("{} {}", mnemonic, args)
+                        };
+                        let _ = writeln!(out, "{:04x}  {:<14} | {}", start_pos, bytes_str, op_str);
+                    }
+                } else {
+                    let extra_width = start_pos.ilog2() >> 4;
+                    if color {
+                        let _ = write!(out, "    ");
+                        for _ in 0..extra_width {
+                            let _ = write!(out, " ");
+                        }
+                        let _ = writeln!(out, "  {:<14} |", bytes_str.green());
+                    } else {
+                        let _ = write!(out, "    ");
+                        for _ in 0..extra_width {
+                            let _ = write!(out, " ");
+                        }
+                        let _ = writeln!(out, "  {:<14} |", bytes_str);
+                    }
+                }
+            }
+        }
+        out
+    }
+
+    fn decode_instruction(&mut self, op_byte: u8, current_pc: usize) -> (&'static str, String) {
+        let op = Op::try_from_primitive(op_byte).expect("invalid op code");
+
+        match op {
+            Op::PushConst => {
+                let idx = self.read_u32();
+                let val = self.ctx.lookup_constant(idx);
+                let val_str = match val {
+                    Constant::Int(i) => format!("Int({})", i),
+                    Constant::Float(f) => format!("Float(bits: {})", f),
+                };
+                ("PushConst", format!("@{} ({})", idx, val_str))
+            }
+            Op::PushString => {
+                let idx = self.read_u32();
+                let s = self.ctx.lookup_string(idx);
+                let len = s.len();
+                let mut s_fmt = format!("{:?}", s);
+                if s_fmt.len() > 60 {
+                    s_fmt.truncate(57);
+                    #[allow(clippy::unwrap_used)]
+                    write!(s_fmt, "...\" (total {len} bytes)").unwrap();
+                }
+                ("PushString", format!("@{} {}", idx, s_fmt))
+            }
+            Op::PushNull => ("PushNull", String::new()),
+            Op::PushTrue => ("PushTrue", String::new()),
+            Op::PushFalse => ("PushFalse", String::new()),
+
+            Op::LoadLocal => {
+                let idx = self.read_u32();
+                ("LoadLocal", format!("[{}]", idx))
+            }
+            Op::LoadOuter => {
+                let depth = self.read_u8();
+                let idx = self.read_u32();
+                ("LoadOuter", format!("depth={} [{}]", depth, idx))
+            }
+            Op::StoreLocal => {
+                let idx = self.read_u32();
+                ("StoreLocal", format!("[{}]", idx))
+            }
+            Op::AllocLocals => {
+                let count = self.read_u32();
+                ("AllocLocals", format!("count={}", count))
+            }
+
+            Op::MakeThunk => {
+                let offset = self.read_u32();
+                let label_idx = self.read_u32();
+                let label = self.ctx.lookup_string(label_idx);
+                ("MakeThunk", format!("-> {:04x} label={}", offset, label))
+            }
+            Op::MakeClosure => {
+                let offset = self.read_u32();
+                let slots = self.read_u32();
+                ("MakeClosure", format!("-> {:04x} slots={}", offset, slots))
+            }
+            Op::MakePatternClosure => {
+                let offset = self.read_u32();
+                let slots = self.read_u32();
+                let req_count = self.read_u16();
+                let opt_count = self.read_u16();
+                let ellipsis = self.read_u8() != 0;
+
+                let mut arg_str = format!(
+                    "-> {:04x} slots={} req={} opt={} ...={})",
+                    offset, slots, req_count, opt_count, ellipsis
+                );
+
+                arg_str.push_str(" Args=[");
+                for _ in 0..req_count {
+                    let idx = self.read_u32();
+                    arg_str.push_str(&format!("Req({}) ", self.ctx.lookup_string(idx)));
+                }
+                for _ in 0..opt_count {
+                    let idx = self.read_u32();
+                    arg_str.push_str(&format!("Opt({}) ", self.ctx.lookup_string(idx)));
+                }
+
+                let total_args = req_count + opt_count;
+                for _ in 0..total_args {
+                    let _name_idx = self.read_u32();
+                    let _span_id = self.read_u32();
+                }
+                arg_str.push(']');
+
+                ("MakePatternClosure", arg_str)
+            }
+
+            Op::Call => {
+                let span_id = self.read_u32();
+                ("Call", format!("span={}", span_id))
+            }
+            Op::CallNoSpan => ("CallNoSpan", String::new()),
+
+            Op::MakeAttrs => {
+                let count = self.read_u32();
+                ("MakeAttrs", format!("size={}", count))
+            }
+            Op::MakeAttrsDyn => {
+                let static_count = self.read_u32();
+                let dyn_count = self.read_u32();
+                (
+                    "MakeAttrsDyn",
+                    format!("static={} dyn={}", static_count, dyn_count),
+                )
+            }
+            Op::MakeEmptyAttrs => ("MakeEmptyAttrs", String::new()),
+
+            Op::Select => {
+                let path_len = self.read_u16();
+                let span_id = self.read_u32();
+                ("Select", format!("path_len={} span={}", path_len, span_id))
+            }
+            Op::SelectDefault => {
+                let path_len = self.read_u16();
+                let span_id = self.read_u32();
+                (
+                    "SelectDefault",
+                    format!("path_len={} span={}", path_len, span_id),
+                )
+            }
+            Op::HasAttr => {
+                let path_len = self.read_u16();
+                ("HasAttr", format!("path_len={}", path_len))
+            }
+
+            Op::MakeList => {
+                let count = self.read_u32();
+                ("MakeList", format!("size={}", count))
+            }
+
+            Op::OpAdd => ("OpAdd", String::new()),
+            Op::OpSub => ("OpSub", String::new()),
+            Op::OpMul => ("OpMul", String::new()),
+            Op::OpDiv => ("OpDiv", String::new()),
+            Op::OpEq => ("OpEq", String::new()),
+            Op::OpNeq => ("OpNeq", String::new()),
+            Op::OpLt => ("OpLt", String::new()),
+            Op::OpGt => ("OpGt", String::new()),
+            Op::OpLeq => ("OpLeq", String::new()),
+            Op::OpGeq => ("OpGeq", String::new()),
+            Op::OpConcat => ("OpConcat", String::new()),
+            Op::OpUpdate => ("OpUpdate", String::new()),
+            Op::OpNeg => ("OpNeg", String::new()),
+            Op::OpNot => ("OpNot", String::new()),
+
+            Op::ForceBool => ("ForceBool", String::new()),
+
+            Op::JumpIfFalse => {
+                let offset = self.read_i32();
+                let target = (current_pc as isize + 1 + 4 + offset as isize) as usize;
+                (
+                    "JumpIfFalse",
+                    format!("-> {:04x} offset={}", target, offset),
+                )
+            }
+            Op::JumpIfTrue => {
+                let offset = self.read_i32();
+                let target = (current_pc as isize + 1 + 4 + offset as isize) as usize;
+                ("JumpIfTrue", format!("-> {:04x} offset={}", target, offset))
+            }
+            Op::Jump => {
+                let offset = self.read_i32();
+                let target = (current_pc as isize + 1 + 4 + offset as isize) as usize;
+                ("Jump", format!("-> {:04x} offset={}", target, offset))
+            }
+
+            Op::ConcatStrings => {
+                let count = self.read_u16();
+                let force = self.read_u8();
+                ("ConcatStrings", format!("count={} force={}", count, force))
+            }
+            Op::ResolvePath => ("ResolvePath", String::new()),
+            Op::Assert => {
+                let raw_idx = self.read_u32();
+                let span_id = self.read_u32();
+                ("Assert", format!("text_id={} span={}", raw_idx, span_id))
+            }
+            Op::PushWith => ("PushWith", String::new()),
+            Op::PopWith => ("PopWith", String::new()),
+            Op::WithLookup => {
+                let idx = self.read_u32();
+                let name = self.ctx.lookup_string(idx);
+                ("WithLookup", format!("{:?}", name))
+            }
+
+            Op::LoadBuiltins => ("LoadBuiltins", String::new()),
+            Op::LoadBuiltin => {
+                let idx = self.read_u32();
+                let name = self.ctx.lookup_string(idx);
+                ("LoadBuiltin", format!("{:?}", name))
+            }
+            Op::MkPos => {
+                let span_id = self.read_u32();
+                ("MkPos", format!("id={}", span_id))
+            }
+            Op::LoadReplBinding => {
+                let idx = self.read_u32();
+                let name = self.ctx.lookup_string(idx);
+                ("LoadReplBinding", format!("{:?}", name))
+            }
+            Op::LoadScopedBinding => {
+                let idx = self.read_u32();
+                let name = self.ctx.lookup_string(idx);
+                ("LoadScopedBinding", format!("{:?}", name))
+            }
+            Op::Return => ("Return", String::new()),
+        }
+    }
+}
--- a/nix-js/src/downgrade.rs
+++ b/nix-js/src/downgrade.rs
--- a/nix-js/src/error.rs
+++ b/nix-js/src/error.rs
@@ -292,43 +292,32 @@ fn parse_frames(stack: &str, ctx: &impl RuntimeContext) -> Vec<NixStackFrame> {
    let mut frames = Vec::new();

    for line in stack.lines() {
-        // Format: NIX_STACK_FRAME:source_id:start:end[:extra_data]
+        // Format: NIX_STACK_FRAME:span_id:message
        let Some(rest) = line.strip_prefix("NIX_STACK_FRAME:") else {
            continue;
        };
-        let parts: Vec<&str> = rest.splitn(4, ':').collect();
+        let parts: Vec<&str> = rest.splitn(2, ':').collect();

-        if parts.len() < 3 {
+        if parts.is_empty() {
            continue;
        }

-        let src = match parts[0].parse() {
-            Ok(id) => ctx.get_source(id),
-            Err(_) => continue,
-        };
-        let start: u32 = match parts[1].parse() {
-            Ok(v) => v,
-            Err(_) => continue,
-        };
-        let end: u32 = match parts[2].parse() {
-            Ok(v) => v,
+        let span_id: usize = match parts[0].parse() {
+            Ok(id) => id,
            Err(_) => continue,
        };
+        let (source_id, span) = ctx.get_span(span_id);
+        let src = ctx.get_source(source_id);

-        let span = rnix::TextRange::new(rnix::TextSize::from(start), rnix::TextSize::from(end));
-
-        let message = {
-            if parts.len() == 4 {
-                parts[3].to_string()
+        let message = if parts.len() == 2 {
+            parts[1].to_string()
        } else {
            String::new()
-            }
        };

        frames.push(NixStackFrame { span, message, src });
    }

-    // Deduplicate consecutive identical frames
    frames.dedup_by(|a, b| a.span == b.span && a.message == b.message);

    frames
--- a/nix-js/src/fetcher.rs
+++ b/nix-js/src/fetcher.rs
@@ -1,8 +1,8 @@
 use deno_core::OpState;
+use deno_core::ToV8;
 use deno_core::op2;
 use nix_compat::nixhash::HashAlgo;
 use nix_compat::nixhash::NixHash;
-use serde::Serialize;
 use tracing::{debug, info, warn};

 use crate::runtime::OpStateExt;
@@ -22,19 +22,19 @@ pub use metadata_cache::MetadataCache;
 use crate::nar;
 use crate::runtime::NixRuntimeError;

-#[derive(Serialize)]
+#[derive(ToV8)]
 pub struct FetchUrlResult {
    pub store_path: String,
    pub hash: String,
 }

-#[derive(Serialize)]
+#[derive(ToV8)]
 pub struct FetchTarballResult {
    pub store_path: String,
    pub nar_hash: String,
 }

-#[derive(Serialize)]
+#[derive(ToV8)]
 pub struct FetchGitResult {
    pub out_path: String,
    pub rev: String,
@@ -47,7 +47,6 @@ pub struct FetchGitResult {
 }

 #[op2]
-#[serde]
 pub fn op_fetch_url<Ctx: RuntimeContext>(
    state: &mut OpState,
    #[string] url: String,
@@ -152,7 +151,6 @@ pub fn op_fetch_url<Ctx: RuntimeContext>(
 }

 #[op2]
-#[serde]
 pub fn op_fetch_tarball<Ctx: RuntimeContext>(
    state: &mut OpState,
    #[string] url: String,
@@ -266,7 +264,6 @@ pub fn op_fetch_tarball<Ctx: RuntimeContext>(
 }

 #[op2]
-#[serde]
 pub fn op_fetch_git<Ctx: RuntimeContext>(
    state: &mut OpState,
    #[string] url: String,
--- a/nix-js/src/fetcher/download.rs
+++ b/nix-js/src/fetcher/download.rs
@@ -1,6 +1,7 @@
-use reqwest::blocking::Client;
 use std::time::Duration;

+use reqwest::blocking::Client;
+
 pub struct Downloader {
    client: Client,
 }
--- a/nix-js/src/fetcher/metadata_cache.rs
+++ b/nix-js/src/fetcher/metadata_cache.rs
@@ -1,9 +1,10 @@
 #![allow(dead_code)]

+use std::path::PathBuf;
+use std::time::{SystemTime, UNIX_EPOCH};
+
 use rusqlite::{Connection, OptionalExtension, params};
 use serde::{Deserialize, Serialize};
-use std::path::PathBuf;
-use std::time::{SystemTime, UNIX_EPOCH};

 #[derive(Debug)]
 pub enum CacheError {
--- a/nix-js/src/ir.rs
+++ b/nix-js/src/ir.rs
@@ -1,46 +1,158 @@
-use derive_more::{IsVariant, TryUnwrap, Unwrap};
-use hashbrown::HashMap;
+use std::{
+    hash::{Hash, Hasher},
+    ops::Deref,
+};
+
+use bumpalo::{Bump, boxed::Box, collections::Vec};
+use ghost_cell::{GhostCell, GhostToken};
 use rnix::{TextRange, ast};
 use string_interner::symbol::SymbolU32;

-use nix_js_macros::ir;
+pub type HashMap<'ir, K, V> = hashbrown::HashMap<K, V, hashbrown::DefaultHashBuilder, &'ir Bump>;

-ir! {
-    Ir,
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct IrRef<'id, 'ir>(&'ir GhostCell<'id, Ir<'ir, Self>>);

+impl<'id, 'ir> IrRef<'id, 'ir> {
+    pub fn new(ir: &'ir GhostCell<'id, Ir<'ir, Self>>) -> Self {
+        Self(ir)
+    }
+
+    pub fn alloc(bump: &'ir Bump, ir: Ir<'ir, Self>) -> Self {
+        Self(bump.alloc(GhostCell::new(ir)))
+    }
+
+    /// Freeze a mutable IR reference into a read-only one, consuming the
+    /// `GhostToken` to prevent any further mutation.
+    ///
+    /// # Safety
+    /// The transmute is sound because:
+    /// - `GhostCell<'id, T>` is `#[repr(transparent)]` over `T`
+    /// - `IrRef<'id, 'ir>` is `#[repr(transparent)]` over
+    ///   `&'ir GhostCell<'id, Ir<'ir, Self>>`
+    /// - `RawIrRef<'ir>` is `#[repr(transparent)]` over `&'ir Ir<'ir, Self>`
+    /// - `Ir<'ir, Ref>` is `#[repr(C)]` and both ref types are pointer-sized
+    ///
+    /// Consuming the `GhostToken` guarantees no `borrow_mut` calls can occur
+    /// afterwards, so the shared `&Ir` references from `RawIrRef::Deref` can
+    /// never alias with mutable references.
+    pub fn freeze(self, _token: GhostToken<'id>) -> RawIrRef<'ir> {
+        unsafe { std::mem::transmute(self) }
+    }
+}
+
+impl<'id, 'ir> Deref for IrRef<'id, 'ir> {
+    type Target = GhostCell<'id, Ir<'ir, IrRef<'id, 'ir>>>;
+    fn deref(&self) -> &Self::Target {
+        self.0
+    }
+}
+
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct RawIrRef<'ir>(&'ir Ir<'ir, Self>);
+
+impl<'ir> Deref for RawIrRef<'ir> {
+    type Target = Ir<'ir, RawIrRef<'ir>>;
+    fn deref(&self) -> &Self::Target {
+        self.0
+    }
+}
+
+#[repr(C)]
+pub enum Ir<'ir, Ref> {
    Int(i64),
    Float(f64),
    Bool(bool),
    Null,
-    Str { pub val: String },
-    AttrSet { pub stcs: HashMap<SymId, (ExprId, rnix::TextRange)>, pub dyns: Vec<(ExprId, ExprId, rnix::TextRange)> },
-    List { pub items: Vec<ExprId> },
+    Str(Box<'ir, String>),
+    AttrSet {
+        stcs: HashMap<'ir, SymId, (Ref, TextRange)>,
+        dyns: Vec<'ir, (Ref, Ref, TextRange)>,
+    },
+    List {
+        items: Vec<'ir, Ref>,
+    },
+    Path(Ref),
+    ConcatStrings {
+        parts: Vec<'ir, Ref>,
+        force_string: bool,
+    },

-    HasAttr { pub lhs: ExprId, pub rhs: Vec<Attr> },
-    BinOp { pub lhs: ExprId, pub rhs: ExprId, pub kind: BinOpKind },
-    UnOp { pub rhs: ExprId, pub kind: UnOpKind },
-    Select { pub expr: ExprId, pub attrpath: Vec<Attr>, pub default: Option<ExprId> },
-    If { pub cond: ExprId, pub consq: ExprId, pub alter: ExprId },
-    Call { pub func: ExprId, pub arg: ExprId },
-    Assert { pub assertion: ExprId, pub expr: ExprId, pub assertion_raw: String },
-    ConcatStrings { pub parts: Vec<ExprId>, pub force_string: bool },
-    Path { pub expr: ExprId },
-    Func { pub body: ExprId, pub param: Option<Param>, pub arg: ExprId, pub thunks: Vec<(ExprId, ExprId)> },
-    TopLevel { pub body: ExprId, pub thunks: Vec<(ExprId, ExprId)> },
+    // OPs
+    UnOp {
+        rhs: Ref,
+        kind: UnOpKind,
+    },
+    BinOp {
+        lhs: Ref,
+        rhs: Ref,
+        kind: BinOpKind,
+    },
+    HasAttr {
+        lhs: Ref,
+        rhs: Vec<'ir, Attr<Ref>>,
+    },
+    Select {
+        expr: Ref,
+        attrpath: Vec<'ir, Attr<Ref>>,
+        default: Option<Ref>,
+        span: TextRange,
+    },
+
+    // Conditionals
+    If {
+        cond: Ref,
+        consq: Ref,
+        alter: Ref,
+    },
+    Assert {
+        assertion: Ref,
+        expr: Ref,
+        assertion_raw: String,
+        span: TextRange,
+    },
+
+    With {
+        namespace: Ref,
+        body: Ref,
+        thunks: Vec<'ir, (ThunkId, Ref)>,
+    },
+    WithLookup(SymId),
+
+    // Function related
+    Func {
+        body: Ref,
+        param: Option<Param<'ir>>,
+        arg: ArgId,
+        thunks: Vec<'ir, (ThunkId, Ref)>,
+    },
    Arg(ArgId),
-    Thunk(ExprId),
+    Call {
+        func: Ref,
+        arg: Ref,
+        span: TextRange,
+    },
+
+    // Builtins
    Builtins,
    Builtin(SymId),
-    CurPos,
+
+    // Misc
+    TopLevel {
+        body: Ref,
+        thunks: Vec<'ir, (ThunkId, Ref)>,
+    },
+    Thunk(ThunkId),
+    CurPos(TextRange),
    ReplBinding(SymId),
    ScopedImportBinding(SymId),
-    WithExpr { pub namespace: ExprId, pub body: ExprId, pub thunks: Vec<(ExprId, ExprId)> },
-    WithLookup(SymId),
 }

 #[repr(transparent)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct ExprId(pub usize);
+pub struct ThunkId(pub usize);

 pub type SymId = SymbolU32;

@@ -50,18 +162,18 @@ pub struct ArgId(pub usize);

 /// Represents a key in an attribute path.
 #[allow(unused)]
-#[derive(Debug, TryUnwrap)]
-pub enum Attr {
+#[derive(Debug)]
+pub enum Attr<Ref> {
    /// A dynamic attribute key, which is an expression that must evaluate to a string.
    /// Example: `attrs.${key}`
-    Dynamic(ExprId, TextRange),
+    Dynamic(Ref, TextRange),
    /// A static attribute key.
    /// Example: `attrs.key`
    Str(SymId, TextRange),
 }

 /// The kinds of binary operations supported in Nix.
-#[derive(Clone, Debug)]
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub enum BinOpKind {
    // Arithmetic
    Add,
@@ -118,7 +230,7 @@ impl From<ast::BinOpKind> for BinOpKind {
 }

 /// The kinds of unary operations.
-#[derive(Clone, Debug)]
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub enum UnOpKind {
    Neg, // Negation (`-`)
    Not, // Logical not (`!`)
@@ -135,8 +247,437 @@ impl From<ast::UnaryOpKind> for UnOpKind {

 /// Describes the parameters of a function.
 #[derive(Debug)]
-pub struct Param {
-    pub required: Vec<(SymId, TextRange)>,
-    pub optional: Vec<(SymId, TextRange)>,
+pub struct Param<'ir> {
+    pub required: Vec<'ir, (SymId, TextRange)>,
+    pub optional: Vec<'ir, (SymId, TextRange)>,
    pub ellipsis: bool,
 }
+
+#[derive(Clone, Copy)]
+pub(crate) struct IrKey<'id, 'ir, 'a>(pub IrRef<'id, 'ir>, pub &'a GhostToken<'id>);
+
+impl std::hash::Hash for IrKey<'_, '_, '_> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        ir_content_hash(self.0, self.1, state);
+    }
+}
+
+impl PartialEq for IrKey<'_, '_, '_> {
+    fn eq(&self, other: &Self) -> bool {
+        ir_content_eq(self.0, other.0, self.1)
+    }
+}
+
+impl Eq for IrKey<'_, '_, '_> {}
+
+fn attr_content_hash<'id>(
+    attr: &Attr<IrRef<'id, '_>>,
+    token: &GhostToken<'id>,
+    state: &mut impl Hasher,
+) {
+    core::mem::discriminant(attr).hash(state);
+    match attr {
+        Attr::Dynamic(expr, _) => ir_content_hash(*expr, token, state),
+        Attr::Str(sym, _) => sym.hash(state),
+    }
+}
+
+fn attr_content_eq<'id, 'ir>(
+    a: &Attr<IrRef<'id, 'ir>>,
+    b: &Attr<IrRef<'id, 'ir>>,
+    token: &GhostToken<'id>,
+) -> bool {
+    match (a, b) {
+        (Attr::Dynamic(ae, _), Attr::Dynamic(be, _)) => ir_content_eq(*ae, *be, token),
+        (Attr::Str(a, _), Attr::Str(b, _)) => a == b,
+        _ => false,
+    }
+}
+
+fn param_content_hash(param: &Param<'_>, state: &mut impl Hasher) {
+    param.required.len().hash(state);
+    for (sym, _) in param.required.iter() {
+        sym.hash(state);
+    }
+    param.optional.len().hash(state);
+    for (sym, _) in param.optional.iter() {
+        sym.hash(state);
+    }
+    param.ellipsis.hash(state);
+}
+
+fn param_content_eq(a: &Param<'_>, b: &Param<'_>) -> bool {
+    a.ellipsis == b.ellipsis
+        && a.required.len() == b.required.len()
+        && a.optional.len() == b.optional.len()
+        && a.required
+            .iter()
+            .zip(b.required.iter())
+            .all(|((a, _), (b, _))| a == b)
+        && a.optional
+            .iter()
+            .zip(b.optional.iter())
+            .all(|((a, _), (b, _))| a == b)
+}
+
+fn thunks_content_hash<'id>(
+    thunks: &[(ThunkId, IrRef<'id, '_>)],
+    token: &GhostToken<'id>,
+    state: &mut impl Hasher,
+) {
+    thunks.len().hash(state);
+    for &(id, ir) in thunks {
+        id.hash(state);
+        ir_content_hash(ir, token, state);
+    }
+}
+
+fn thunks_content_eq<'id, 'ir>(
+    a: &[(ThunkId, IrRef<'id, 'ir>)],
+    b: &[(ThunkId, IrRef<'id, 'ir>)],
+    token: &GhostToken<'id>,
+) -> bool {
+    a.len() == b.len()
+        && a.iter()
+            .zip(b.iter())
+            .all(|(&(ai, ae), &(bi, be))| ai == bi && ir_content_eq(ae, be, token))
+}
+
+fn ir_content_hash<'id>(ir: IrRef<'id, '_>, token: &GhostToken<'id>, state: &mut impl Hasher) {
+    let ir = ir.borrow(token);
+    core::mem::discriminant(ir).hash(state);
+    match ir {
+        Ir::Int(x) => x.hash(state),
+        Ir::Float(x) => x.to_bits().hash(state),
+        Ir::Bool(x) => x.hash(state),
+        Ir::Null => {}
+        Ir::Str(x) => x.hash(state),
+        Ir::AttrSet { stcs, dyns } => {
+            stcs.len().hash(state);
+            let mut combined: u64 = 0;
+            for (&key, &(val, _)) in stcs.iter() {
+                let mut h = std::hash::DefaultHasher::new();
+                key.hash(&mut h);
+                ir_content_hash(val, token, &mut h);
+                combined = combined.wrapping_add(h.finish());
+            }
+            combined.hash(state);
+            dyns.len().hash(state);
+            for &(k, v, _) in dyns.iter() {
+                ir_content_hash(k, token, state);
+                ir_content_hash(v, token, state);
+            }
+        }
+        Ir::List { items } => {
+            items.len().hash(state);
+            for &item in items.iter() {
+                ir_content_hash(item, token, state);
+            }
+        }
+        Ir::HasAttr { lhs, rhs } => {
+            ir_content_hash(*lhs, token, state);
+            rhs.len().hash(state);
+            for attr in rhs.iter() {
+                attr_content_hash(attr, token, state);
+            }
+        }
+        &Ir::BinOp { lhs, rhs, kind } => {
+            ir_content_hash(lhs, token, state);
+            ir_content_hash(rhs, token, state);
+            kind.hash(state);
+        }
+        &Ir::UnOp { rhs, kind } => {
+            ir_content_hash(rhs, token, state);
+            kind.hash(state);
+        }
+        Ir::Select {
+            expr,
+            attrpath,
+            default,
+            ..
+        } => {
+            ir_content_hash(*expr, token, state);
+            attrpath.len().hash(state);
+            for attr in attrpath.iter() {
+                attr_content_hash(attr, token, state);
+            }
+            default.is_some().hash(state);
+            if let Some(d) = default {
+                ir_content_hash(*d, token, state);
+            }
+        }
+        &Ir::If { cond, consq, alter } => {
+            ir_content_hash(cond, token, state);
+            ir_content_hash(consq, token, state);
+            ir_content_hash(alter, token, state);
+        }
+        &Ir::Call { func, arg, .. } => {
+            ir_content_hash(func, token, state);
+            ir_content_hash(arg, token, state);
+        }
+        Ir::Assert {
+            assertion,
+            expr,
+            assertion_raw,
+            ..
+        } => {
+            ir_content_hash(*assertion, token, state);
+            ir_content_hash(*expr, token, state);
+            assertion_raw.hash(state);
+        }
+        Ir::ConcatStrings {
+            force_string,
+            parts,
+        } => {
+            force_string.hash(state);
+            parts.len().hash(state);
+            for &part in parts.iter() {
+                ir_content_hash(part, token, state);
+            }
+        }
+        &Ir::Path(expr) => ir_content_hash(expr, token, state),
+        Ir::Func {
+            body,
+            arg,
+            param,
+            thunks,
+        } => {
+            ir_content_hash(*body, token, state);
+            arg.hash(state);
+            param.is_some().hash(state);
+            if let Some(p) = param {
+                param_content_hash(p, state);
+            }
+            thunks_content_hash(thunks, token, state);
+        }
+        Ir::TopLevel { body, thunks } => {
+            ir_content_hash(*body, token, state);
+            thunks_content_hash(thunks, token, state);
+        }
+        Ir::Arg(x) => x.hash(state),
+        Ir::Thunk(x) => x.hash(state),
+        Ir::Builtins => {}
+        Ir::Builtin(x) => x.hash(state),
+        Ir::CurPos(x) => x.hash(state),
+        Ir::ReplBinding(x) => x.hash(state),
+        Ir::ScopedImportBinding(x) => x.hash(state),
+        &Ir::With {
+            namespace,
+            body,
+            ref thunks,
+        } => {
+            ir_content_hash(namespace, token, state);
+            ir_content_hash(body, token, state);
+            thunks_content_hash(thunks, token, state);
+        }
+        Ir::WithLookup(x) => x.hash(state),
+    }
+}
+
+pub(crate) fn ir_content_eq<'id, 'ir>(
+    a: IrRef<'id, 'ir>,
+    b: IrRef<'id, 'ir>,
+    token: &GhostToken<'id>,
+) -> bool {
+    std::ptr::eq(a.0, b.0)
+        || match (a.borrow(token), b.borrow(token)) {
+            (Ir::Int(a), Ir::Int(b)) => a == b,
+            (Ir::Float(a), Ir::Float(b)) => a.to_bits() == b.to_bits(),
+            (Ir::Bool(a), Ir::Bool(b)) => a == b,
+            (Ir::Null, Ir::Null) => true,
+            (Ir::Str(a), Ir::Str(b)) => **a == **b,
+            (
+                Ir::AttrSet {
+                    stcs: a_stcs,
+                    dyns: a_dyns,
+                },
+                Ir::AttrSet {
+                    stcs: b_stcs,
+                    dyns: b_dyns,
+                },
+            ) => {
+                a_stcs.len() == b_stcs.len()
+                    && a_dyns.len() == b_dyns.len()
+                    && a_stcs.iter().all(|(&k, &(av, _))| {
+                        b_stcs
+                            .get(&k)
+                            .is_some_and(|&(bv, _)| ir_content_eq(av, bv, token))
+                    })
+                    && a_dyns
+                        .iter()
+                        .zip(b_dyns.iter())
+                        .all(|(&(ak, av, _), &(bk, bv, _))| {
+                            ir_content_eq(ak, bk, token) && ir_content_eq(av, bv, token)
+                        })
+            }
+            (Ir::List { items: a }, Ir::List { items: b }) => {
+                a.len() == b.len()
+                    && a.iter()
+                        .zip(b.iter())
+                        .all(|(&a, &b)| ir_content_eq(a, b, token))
+            }
+            (Ir::HasAttr { lhs: al, rhs: ar }, Ir::HasAttr { lhs: bl, rhs: br }) => {
+                ir_content_eq(*al, *bl, token)
+                    && ar.len() == br.len()
+                    && ar
+                        .iter()
+                        .zip(br.iter())
+                        .all(|(a, b)| attr_content_eq(a, b, token))
+            }
+            (
+                &Ir::BinOp {
+                    lhs: al,
+                    rhs: ar,
+                    kind: ak,
+                },
+                &Ir::BinOp {
+                    lhs: bl,
+                    rhs: br,
+                    kind: bk,
+                },
+            ) => ak == bk && ir_content_eq(al, bl, token) && ir_content_eq(ar, br, token),
+            (&Ir::UnOp { rhs: ar, kind: ak }, &Ir::UnOp { rhs: br, kind: bk }) => {
+                ak == bk && ir_content_eq(ar, br, token)
+            }
+            (
+                Ir::Select {
+                    expr: ae,
+                    attrpath: aa,
+                    default: ad,
+                    ..
+                },
+                Ir::Select {
+                    expr: be,
+                    attrpath: ba,
+                    default: bd,
+                    ..
+                },
+            ) => {
+                ir_content_eq(*ae, *be, token)
+                    && aa.len() == ba.len()
+                    && aa
+                        .iter()
+                        .zip(ba.iter())
+                        .all(|(a, b)| attr_content_eq(a, b, token))
+                    && match (ad, bd) {
+                        (Some(a), Some(b)) => ir_content_eq(*a, *b, token),
+                        (None, None) => true,
+                        _ => false,
+                    }
+            }
+            (
+                &Ir::If {
+                    cond: ac,
+                    consq: acs,
+                    alter: aa,
+                },
+                &Ir::If {
+                    cond: bc,
+                    consq: bcs,
+                    alter: ba,
+                },
+            ) => {
+                ir_content_eq(ac, bc, token)
+                    && ir_content_eq(acs, bcs, token)
+                    && ir_content_eq(aa, ba, token)
+            }
+            (
+                &Ir::Call {
+                    func: af, arg: aa, ..
+                },
+                &Ir::Call {
+                    func: bf, arg: ba, ..
+                },
+            ) => ir_content_eq(af, bf, token) && ir_content_eq(aa, ba, token),
+            (
+                Ir::Assert {
+                    assertion: aa,
+                    expr: ae,
+                    assertion_raw: ar,
+                    ..
+                },
+                Ir::Assert {
+                    assertion: ba,
+                    expr: be,
+                    assertion_raw: br,
+                    ..
+                },
+            ) => ar == br && ir_content_eq(*aa, *ba, token) && ir_content_eq(*ae, *be, token),
+            (
+                Ir::ConcatStrings {
+                    force_string: af,
+                    parts: ap,
+                },
+                Ir::ConcatStrings {
+                    force_string: bf,
+                    parts: bp,
+                },
+            ) => {
+                af == bf
+                    && ap.len() == bp.len()
+                    && ap
+                        .iter()
+                        .zip(bp.iter())
+                        .all(|(&a, &b)| ir_content_eq(a, b, token))
+            }
+            (&Ir::Path(a), &Ir::Path(b)) => ir_content_eq(a, b, token),
+            (
+                Ir::Func {
+                    body: ab,
+                    arg: aa,
+                    param: ap,
+                    thunks: at,
+                },
+                Ir::Func {
+                    body: bb,
+                    arg: ba,
+                    param: bp,
+                    thunks: bt,
+                },
+            ) => {
+                ir_content_eq(*ab, *bb, token)
+                    && aa == ba
+                    && match (ap, bp) {
+                        (Some(a), Some(b)) => param_content_eq(a, b),
+                        (None, None) => true,
+                        _ => false,
+                    }
+                    && thunks_content_eq(at, bt, token)
+            }
+            (
+                Ir::TopLevel {
+                    body: ab,
+                    thunks: at,
+                },
+                Ir::TopLevel {
+                    body: bb,
+                    thunks: bt,
+                },
+            ) => ir_content_eq(*ab, *bb, token) && thunks_content_eq(at, bt, token),
+            (Ir::Arg(a), Ir::Arg(b)) => a == b,
+            (Ir::Thunk(a), Ir::Thunk(b)) => a == b,
+            (Ir::Builtins, Ir::Builtins) => true,
+            (Ir::Builtin(a), Ir::Builtin(b)) => a == b,
+            (Ir::CurPos(a), Ir::CurPos(b)) => a == b,
+            (Ir::ReplBinding(a), Ir::ReplBinding(b)) => a == b,
+            (Ir::ScopedImportBinding(a), Ir::ScopedImportBinding(b)) => a == b,
+            (
+                Ir::With {
+                    namespace: a_ns,
+                    body: a_body,
+                    thunks: a_thunks,
+                },
+                Ir::With {
+                    namespace: b_ns,
+                    body: b_body,
+                    thunks: b_thunks,
+                },
+            ) => {
+                ir_content_eq(*a_ns, *b_ns, token)
+                    && ir_content_eq(*a_body, *b_body, token)
+                    && thunks_content_eq(a_thunks, b_thunks, token)
+            }
+            (Ir::WithLookup(a), Ir::WithLookup(b)) => a == b,
+            _ => false,
+        }
+}
--- a/nix-js/src/lib.rs
+++ b/nix-js/src/lib.rs
@@ -5,7 +5,10 @@ pub mod error;
 pub mod logging;
 pub mod value;

+mod bytecode;
 mod codegen;
+mod derivation;
+mod disassembler;
 mod downgrade;
 mod fetcher;
 mod ir;
@@ -13,6 +16,7 @@ mod nar;
 mod nix_utils;
 mod runtime;
 mod store;
+mod string_context;

 #[global_allocator]
 static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
--- a/nix-js/src/logging.rs
+++ b/nix-js/src/logging.rs
@@ -1,5 +1,6 @@
 use std::env;
 use std::io::IsTerminal;
+
 use tracing_subscriber::{EnvFilter, Layer, fmt, layer::SubscriberExt, util::SubscriberInitExt};

 pub fn init_logging() {
--- a/nix-js/src/main.rs
+++ b/nix-js/src/main.rs
@@ -0,0 +1,187 @@
+use std::path::PathBuf;
+use std::process::exit;
+
+use anyhow::Result;
+use clap::{Args, Parser, Subcommand};
+use hashbrown::HashSet;
+use nix_js::context::Context;
+use nix_js::error::Source;
+use rustyline::DefaultEditor;
+use rustyline::error::ReadlineError;
+
+#[derive(Parser)]
+#[command(name = "nix-js", about = "Nix expression evaluator")]
+struct Cli {
+    #[cfg(feature = "inspector")]
+    #[arg(long, value_name = "HOST:PORT", num_args = 0..=1, default_missing_value = "127.0.0.1:9229")]
+    inspect: Option<String>,
+
+    #[cfg(feature = "inspector")]
+    #[arg(long, value_name = "HOST:PORT", num_args = 0..=1, default_missing_value = "127.0.0.1:9229")]
+    inspect_brk: Option<String>,
+
+    #[command(subcommand)]
+    command: Command,
+}
+
+#[derive(Subcommand)]
+enum Command {
+    Compile {
+        #[clap(flatten)]
+        source: ExprSource,
+        #[arg(long)]
+        silent: bool,
+    },
+    Eval {
+        #[clap(flatten)]
+        source: ExprSource,
+    },
+    Repl,
+}
+
+#[derive(Args)]
+#[group(required = true, multiple = false)]
+struct ExprSource {
+    #[clap(short, long)]
+    expr: Option<String>,
+    #[clap(short, long)]
+    file: Option<PathBuf>,
+}
+
+fn create_context(#[cfg(feature = "inspector")] cli: &Cli) -> Result<Context> {
+    #[cfg(feature = "inspector")]
+    {
+        let (addr_str, wait) = if let Some(ref addr) = cli.inspect_brk {
+            (Some(addr.as_str()), true)
+        } else if let Some(ref addr) = cli.inspect {
+            (Some(addr.as_str()), false)
+        } else {
+            (None, false)
+        };
+
+        if let Some(addr_str) = addr_str {
+            let addr: std::net::SocketAddr = addr_str
+                .parse()
+                .map_err(|e| anyhow::anyhow!("invalid inspector address '{}': {}", addr_str, e))?;
+            return Ok(Context::new_with_inspector(addr, wait)?);
+        }
+    }
+    Ok(Context::new()?)
+}
+
+fn run_compile(context: &mut Context, src: ExprSource, silent: bool) -> Result<()> {
+    let src = if let Some(expr) = src.expr {
+        Source::new_eval(expr)?
+    } else if let Some(file) = src.file {
+        Source::new_file(file)?
+    } else {
+        unreachable!()
+    };
+    match context.compile_bytecode(src) {
+        Ok(compiled) => {
+            if !silent {
+                println!("{}", context.disassemble_colored(&compiled));
+            }
+        }
+        Err(err) => {
+            eprintln!("{:?}", miette::Report::new(*err));
+            exit(1);
+        }
+    };
+    #[cfg(feature = "inspector")]
+    context.wait_for_inspector_disconnect();
+    Ok(())
+}
+
+fn run_eval(context: &mut Context, src: ExprSource) -> Result<()> {
+    let src = if let Some(expr) = src.expr {
+        Source::new_eval(expr)?
+    } else if let Some(file) = src.file {
+        Source::new_file(file)?
+    } else {
+        unreachable!()
+    };
+    match context.eval_deep(src) {
+        Ok(value) => {
+            println!("{}", value.display_compat());
+        }
+        Err(err) => {
+            eprintln!("{:?}", miette::Report::new(*err));
+            exit(1);
+        }
+    };
+    #[cfg(feature = "inspector")]
+    context.wait_for_inspector_disconnect();
+    Ok(())
+}
+
+fn run_repl(context: &mut Context) -> Result<()> {
+    let mut rl = DefaultEditor::new()?;
+    let mut scope = HashSet::new();
+    const RE: ere::Regex<3> = ere::compile_regex!("^[ \t]*([a-zA-Z_][a-zA-Z0-9_'-]*)[ \t]*(.*)$");
+    loop {
+        let readline = rl.readline("nix-js-repl> ");
+        match readline {
+            Ok(line) => {
+                if line.trim().is_empty() {
+                    continue;
+                }
+                let _ = rl.add_history_entry(line.as_str());
+                if let Some([Some(_), Some(ident), Some(rest)]) = RE.exec(&line) {
+                    if let Some(expr) = rest.strip_prefix('=') {
+                        let expr = expr.trim_start();
+                        if expr.is_empty() {
+                            eprintln!("Error: missing expression after '='");
+                            continue;
+                        }
+                        match context.add_binding(ident, expr, &mut scope) {
+                            Ok(value) => println!("{} = {}", ident, value),
+                            Err(err) => eprintln!("{:?}", miette::Report::new(*err)),
+                        }
+                    } else {
+                        let src = Source::new_repl(line)?;
+                        match context.eval_repl(src, &scope) {
+                            Ok(value) => println!("{value}"),
+                            Err(err) => eprintln!("{:?}", miette::Report::new(*err)),
+                        }
+                    }
+                } else {
+                    let src = Source::new_repl(line)?;
+                    match context.eval_shallow(src) {
+                        Ok(value) => println!("{value}"),
+                        Err(err) => eprintln!("{:?}", miette::Report::new(*err)),
+                    }
+                }
+            }
+            Err(ReadlineError::Interrupted) => {
+                println!();
+            }
+            Err(ReadlineError::Eof) => {
+                println!("CTRL-D");
+                break;
+            }
+            Err(err) => {
+                eprintln!("Error: {err:?}");
+                break;
+            }
+        }
+    }
+    Ok(())
+}
+
+fn main() -> Result<()> {
+    nix_js::logging::init_logging();
+
+    let cli = Cli::parse();
+
+    let mut context = create_context(
+        #[cfg(feature = "inspector")]
+        &cli,
+    )?;
+
+    match cli.command {
+        Command::Compile { source, silent } => run_compile(&mut context, source, silent),
+        Command::Eval { source } => run_eval(&mut context, source),
+        Command::Repl => run_repl(&mut context),
+    }
+}
--- a/nix-js/src/nar.rs
+++ b/nix-js/src/nar.rs
@@ -1,8 +1,9 @@
-use nix_nar::Encoder;
-use sha2::{Digest, Sha256};
 use std::io::Read;
 use std::path::Path;

+use nix_nar::Encoder;
+use sha2::{Digest, Sha256};
+
 use crate::error::{Error, Result};

 pub fn compute_nar_hash(path: &Path) -> Result<[u8; 32]> {
@@ -27,11 +28,13 @@ pub fn pack_nar(path: &Path) -> Result<Vec<u8>> {
 #[cfg(test)]
 #[allow(clippy::unwrap_used)]
 mod tests {
-    use super::*;
    use std::fs;
+
    use tempfile::TempDir;

-    #[test]
+    use super::*;
+
+    #[test_log::test]
    fn test_simple_file() {
        let temp = TempDir::new().unwrap();
        let file_path = temp.path().join("test.txt");
@@ -46,7 +49,7 @@ mod tests {
        assert_eq!(hash.len(), 64);
    }

-    #[test]
+    #[test_log::test]
    fn test_directory() {
        let temp = TempDir::new().unwrap();
        fs::write(temp.path().join("a.txt"), "aaa").unwrap();
--- a/nix-js/src/runtime.rs
+++ b/nix-js/src/runtime.rs
@@ -2,12 +2,17 @@ use std::borrow::Cow;
 use std::marker::PhantomData;
 use std::path::Path;

+#[cfg(feature = "inspector")]
+use deno_core::PollEventLoopOptions;
 use deno_core::{Extension, ExtensionFileSource, JsRuntime, OpState, RuntimeOptions, v8};

+use crate::bytecode::{Bytecode, Constant};
 use crate::error::{Error, Result, Source};
 use crate::store::DaemonStore;
 use crate::value::{AttrSet, List, Symbol, Value};

+#[cfg(feature = "inspector")]
+pub(crate) mod inspector;
 mod ops;
 use ops::*;

@@ -20,8 +25,12 @@ pub(crate) trait RuntimeContext: 'static {
    fn add_source(&mut self, path: Source);
    fn compile(&mut self, source: Source) -> Result<String>;
    fn compile_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<String>;
+    fn compile_bytecode(&mut self, source: Source) -> Result<Bytecode>;
+    fn compile_bytecode_scoped(&mut self, source: Source, scope: Vec<String>) -> Result<Bytecode>;
    fn get_source(&self, id: usize) -> Source;
    fn get_store(&self) -> &DaemonStore;
+    fn get_span(&self, id: usize) -> (usize, rnix::TextRange);
+    fn get_unsynced(&mut self) -> (&[String], &[Constant], usize, usize);
 }

 pub(crate) trait OpStateExt<Ctx: RuntimeContext> {
@@ -46,31 +55,30 @@ fn runtime_extension<Ctx: RuntimeContext>() -> Extension {
    let mut ops = vec![
        op_import::<Ctx>(),
        op_scoped_import::<Ctx>(),
+        op_resolve_path(),
        op_read_file(),
        op_read_file_type(),
        op_read_dir(),
        op_path_exists(),
-        op_resolve_path(),
-        op_sha256_hex(),
+        op_walk_dir(),
        op_make_placeholder(),
-        op_decode_span::<Ctx>(),
-        op_make_store_path::<Ctx>(),
-        op_parse_hash(),
-        op_make_fixed_output_path::<Ctx>(),
-        op_add_path::<Ctx>(),
        op_store_path::<Ctx>(),
+        op_convert_hash(),
+        op_hash_string(),
+        op_hash_file(),
+        op_parse_hash(),
+        op_add_path::<Ctx>(),
+        op_add_filtered_path::<Ctx>(),
+        op_decode_span::<Ctx>(),
        op_to_file::<Ctx>(),
-        op_write_derivation::<Ctx>(),
-        op_read_derivation_outputs(),
-        op_compute_fs_closure(),
        op_copy_path_to_store::<Ctx>(),
        op_get_env(),
-        op_walk_dir(),
-        op_add_filtered_path::<Ctx>(),
        op_match(),
        op_split(),
        op_from_json(),
        op_from_toml(),
+        op_finalize_derivation::<Ctx>(),
+        op_to_xml(),
    ];
    ops.extend(crate::fetcher::register_ops::<Ctx>());

@@ -86,9 +94,8 @@ fn runtime_extension<Ctx: RuntimeContext>() -> Extension {

 mod private {
    use deno_error::js_error_wrapper;
-    #[allow(dead_code)]
    #[derive(Debug)]
-    pub struct SimpleErrorWrapper(pub(crate) String);
+    pub struct SimpleErrorWrapper(String);
    impl std::fmt::Display for SimpleErrorWrapper {
        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
            std::fmt::Display::fmt(&self.0, f)
@@ -113,24 +120,37 @@ pub(crate) use private::NixRuntimeError;

 pub(crate) struct Runtime<Ctx: RuntimeContext> {
    js_runtime: JsRuntime,
-    is_thunk_symbol: v8::Global<v8::Symbol>,
-    primop_metadata_symbol: v8::Global<v8::Symbol>,
-    has_context_symbol: v8::Global<v8::Symbol>,
-    is_path_symbol: v8::Global<v8::Symbol>,
-    is_cycle_symbol: v8::Global<v8::Symbol>,
+    #[cfg(feature = "inspector")]
+    rt: tokio::runtime::Runtime,
+    #[cfg(feature = "inspector")]
+    wait_for_inspector: bool,
+    symbols: GlobalSymbols,
+    cached_fns: CachedFunctions,
    _marker: PhantomData<Ctx>,
 }

+#[cfg(feature = "inspector")]
+#[derive(Debug, Clone, Copy, Default)]
+pub(crate) struct InspectorOptions {
+    pub(crate) enable: bool,
+    pub(crate) wait: bool,
+}
+
 impl<Ctx: RuntimeContext> Runtime<Ctx> {
-    pub(crate) fn new() -> Result<Self> {
+    pub(crate) fn new(
+        #[cfg(feature = "inspector")] inspector_options: InspectorOptions,
+    ) -> Result<Self> {
        use std::sync::Once;

-        // Initialize V8 once
        static INIT: Once = Once::new();
        INIT.call_once(|| {
-            // First flag is always not recognized
            assert_eq!(
-                deno_core::v8_set_flags(vec!["".into(), format!("--stack-size={}", 8 * 1024)]),
+                deno_core::v8_set_flags(vec![
+                    "".into(),
+                    format!("--stack-size={}", 8 * 1024),
+                    #[cfg(feature = "prof")]
+                    ("--prof".into())
+                ]),
                [""]
            );
            JsRuntime::init_platform(Some(v8::new_default_platform(0, false).make_shared()));
@@ -138,37 +158,64 @@ impl<Ctx: RuntimeContext> Runtime<Ctx> {

        let mut js_runtime = JsRuntime::new(RuntimeOptions {
            extensions: vec![runtime_extension::<Ctx>()],
+            #[cfg(feature = "inspector")]
+            inspector: inspector_options.enable,
+            is_main: true,
            ..Default::default()
        });

        js_runtime.op_state().borrow_mut().put(RegexCache::new());
+        js_runtime.op_state().borrow_mut().put(DrvHashCache::new());

-        let (
-            is_thunk_symbol,
-            primop_metadata_symbol,
-            has_context_symbol,
-            is_path_symbol,
-            is_cycle_symbol,
-        ) = {
+        let (symbols, cached_fns) = {
            deno_core::scope!(scope, &mut js_runtime);
-            Self::get_symbols(scope)?
+            let symbols = Self::get_symbols(scope)?;
+            let cached_fns = Self::get_cached_functions(scope)?;
+            (symbols, cached_fns)
        };

        Ok(Self {
            js_runtime,
-            is_thunk_symbol,
-            primop_metadata_symbol,
-            has_context_symbol,
-            is_path_symbol,
-            is_cycle_symbol,
+            #[cfg(feature = "inspector")]
+            rt: tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .expect("failed to build tokio runtime"),
+            #[cfg(feature = "inspector")]
+            wait_for_inspector: inspector_options.wait,
+            symbols,
+            cached_fns,
            _marker: PhantomData,
        })
    }

+    #[cfg(feature = "inspector")]
+    pub(crate) fn inspector(&self) -> std::rc::Rc<deno_core::JsRuntimeInspector> {
+        self.js_runtime.inspector()
+    }
+
+    #[cfg(feature = "inspector")]
+    pub(crate) fn wait_for_inspector_disconnect(&mut self) {
+        let _ = self
+            .rt
+            .block_on(self.js_runtime.run_event_loop(PollEventLoopOptions {
+                wait_for_inspector: true,
+                ..Default::default()
+            }));
+    }
+
    pub(crate) fn eval(&mut self, script: String, ctx: &mut Ctx) -> Result<Value> {
        let ctx: &'static mut Ctx = unsafe { &mut *(ctx as *mut Ctx) };
        self.js_runtime.op_state().borrow_mut().put(ctx);

+        #[cfg(feature = "inspector")]
+        if self.wait_for_inspector {
+            self.js_runtime
+                .inspector()
+                .wait_for_session_and_break_on_next_statement();
+        } else {
+            self.js_runtime.inspector().wait_for_session();
+        }
        let global_value = self
            .js_runtime
            .execute_script("<eval>", script)
@@ -183,34 +230,93 @@ impl<Ctx: RuntimeContext> Runtime<Ctx> {
        // Retrieve scope from JsRuntime
        deno_core::scope!(scope, self.js_runtime);
        let local_value = v8::Local::new(scope, &global_value);
-        let is_thunk_symbol = v8::Local::new(scope, &self.is_thunk_symbol);
-        let primop_metadata_symbol = v8::Local::new(scope, &self.primop_metadata_symbol);
-        let has_context_symbol = v8::Local::new(scope, &self.has_context_symbol);
-        let is_path_symbol = v8::Local::new(scope, &self.is_path_symbol);
-        let is_cycle_symbol = v8::Local::new(scope, &self.is_cycle_symbol);
+        let symbols = &self.symbols.local(scope);

-        Ok(to_value(
-            local_value,
-            scope,
-            is_thunk_symbol,
-            primop_metadata_symbol,
-            has_context_symbol,
-            is_path_symbol,
-            is_cycle_symbol,
-        ))
+        Ok(to_value(local_value, scope, symbols))
    }

-    /// get (IS_THUNK, PRIMOP_METADATA, HAS_CONTEXT, IS_PATH, IS_CYCLE)
-    #[allow(clippy::type_complexity)]
-    fn get_symbols(
-        scope: &ScopeRef,
-    ) -> Result<(
-        v8::Global<v8::Symbol>,
-        v8::Global<v8::Symbol>,
-        v8::Global<v8::Symbol>,
-        v8::Global<v8::Symbol>,
-        v8::Global<v8::Symbol>,
-    )> {
+    pub(crate) fn eval_bytecode(
+        &mut self,
+        result: Bytecode,
+        ctx: &mut Ctx,
+        force_mode: ForceMode,
+    ) -> Result<Value> {
+        let ctx: &'static mut Ctx = unsafe { &mut *(ctx as *mut Ctx) };
+        {
+            deno_core::scope!(scope, self.js_runtime);
+            sync_global_tables(scope, &self.cached_fns, ctx);
+        }
+        let op_state = self.js_runtime.op_state();
+        op_state.borrow_mut().put(ctx);
+
+        #[cfg(feature = "inspector")]
+        if self.wait_for_inspector {
+            self.js_runtime
+                .inspector()
+                .wait_for_session_and_break_on_next_statement();
+        } else {
+            self.js_runtime.inspector().wait_for_session();
+        }
+
+        deno_core::scope!(scope, self.js_runtime);
+
+        let store = v8::ArrayBuffer::new_backing_store_from_boxed_slice(result.code);
+        let ab = v8::ArrayBuffer::with_backing_store(scope, &store.make_shared());
+        let u8a = v8::Uint8Array::new(scope, ab, 0, ab.byte_length())
+            .ok_or_else(|| Error::internal("failed to create Uint8Array".into()))?;
+
+        let dir = v8::String::new(scope, &result.current_dir)
+            .ok_or_else(|| Error::internal("failed to create dir string".into()))?;
+
+        let undef = v8::undefined(scope);
+        let tc = std::pin::pin!(v8::TryCatch::new(scope));
+        let scope = &mut tc.init();
+
+        let exec_bytecode = v8::Local::new(scope, &self.cached_fns.exec_bytecode);
+        let raw_result = exec_bytecode
+            .call(scope, undef.into(), &[u8a.into(), dir.into()])
+            .ok_or_else(|| {
+                scope
+                    .exception()
+                    .map(|e| {
+                        let op_state_borrow = op_state.borrow();
+                        let ctx: &Ctx = op_state_borrow.get_ctx();
+                        Box::new(crate::error::parse_js_error(
+                            deno_core::error::JsError::from_v8_exception(scope, e),
+                            ctx,
+                        ))
+                    })
+                    .unwrap_or_else(|| Error::internal("bytecode execution failed".into()))
+            })?;
+
+        let force_fn = match force_mode {
+            ForceMode::Force => &self.cached_fns.force_fn,
+            ForceMode::ForceShallow => &self.cached_fns.force_shallow_fn,
+            ForceMode::ForceDeep => &self.cached_fns.force_deep_fn,
+        };
+        let force_fn = v8::Local::new(scope, force_fn);
+
+        let forced = force_fn
+            .call(scope, undef.into(), &[raw_result])
+            .ok_or_else(|| {
+                scope
+                    .exception()
+                    .map(|e| {
+                        let op_state_borrow = op_state.borrow();
+                        let ctx: &Ctx = op_state_borrow.get_ctx();
+                        Box::new(crate::error::parse_js_error(
+                            deno_core::error::JsError::from_v8_exception(scope, e),
+                            ctx,
+                        ))
+                    })
+                    .unwrap_or_else(|| Error::internal("force failed".into()))
+            })?;
+
+        let symbols = &self.symbols.local(scope);
+        Ok(to_value(forced, scope, symbols))
+    }
+
+    fn get_symbols(scope: &ScopeRef) -> Result<GlobalSymbols> {
        let global = scope.get_current_context().global(scope);
        let nix_key = v8::String::new(scope, "Nix")
            .ok_or_else(|| Error::internal("failed to create V8 String".into()))?;
@@ -242,18 +348,148 @@ impl<Ctx: RuntimeContext> Runtime<Ctx> {
        let is_path = get_symbol("IS_PATH")?;
        let is_cycle = get_symbol("IS_CYCLE")?;

-        Ok((is_thunk, primop_metadata, has_context, is_path, is_cycle))
+        Ok(GlobalSymbols {
+            is_thunk,
+            primop_metadata,
+            has_context,
+            is_path,
+            is_cycle,
+        })
+    }
+
+    fn get_cached_functions(scope: &ScopeRef) -> Result<CachedFunctions> {
+        let global = scope.get_current_context().global(scope);
+        let nix_key = v8::String::new(scope, "Nix")
+            .ok_or_else(|| Error::internal("failed to create V8 String".into()))?;
+        let nix_obj = global
+            .get(scope, nix_key.into())
+            .ok_or_else(|| Error::internal("failed to get global Nix object".into()))?
+            .to_object(scope)
+            .ok_or_else(|| {
+                Error::internal("failed to convert global Nix Value to object".into())
+            })?;
+
+        let get_fn = |name: &str| -> Result<v8::Global<v8::Function>> {
+            let key = v8::String::new(scope, name)
+                .ok_or_else(|| Error::internal("failed to create V8 String".into()))?;
+            let val = nix_obj
+                .get(scope, key.into())
+                .ok_or_else(|| Error::internal(format!("failed to get Nix.{name}")))?;
+            let func = val
+                .try_cast::<v8::Function>()
+                .map_err(|err| Error::internal(format!("Nix.{name} is not a function ({err})")))?;
+            Ok(v8::Global::new(scope, func))
+        };
+
+        let exec_bytecode = get_fn("execBytecode")?;
+        let force_fn = get_fn("force")?;
+        let force_shallow_fn = get_fn("forceShallow")?;
+        let force_deep_fn = get_fn("forceDeep")?;
+
+        let strings_key = v8::String::new(scope, "strings")
+            .ok_or_else(|| Error::internal("failed to create V8 String".into()))?;
+        let strings_array = nix_obj
+            .get(scope, strings_key.into())
+            .ok_or_else(|| Error::internal("failed to get Nix.strings".into()))?
+            .try_cast::<v8::Array>()
+            .map_err(|err| Error::internal(format!("Nix.strings is not an array ({err})")))?;
+
+        let constants_key = v8::String::new(scope, "constants")
+            .ok_or_else(|| Error::internal("failed to create V8 String".into()))?;
+        let constants_array = nix_obj
+            .get(scope, constants_key.into())
+            .ok_or_else(|| Error::internal("failed to get Nix.constants".into()))?
+            .try_cast::<v8::Array>()
+            .map_err(|err| Error::internal(format!("Nix.constants is not an array ({err})")))?;
+
+        Ok(CachedFunctions {
+            exec_bytecode,
+            force_fn,
+            force_shallow_fn,
+            force_deep_fn,
+            strings_array: v8::Global::new(scope, strings_array),
+            constants_array: v8::Global::new(scope, constants_array),
+        })
+    }
+}
+
+struct GlobalSymbols {
+    is_thunk: v8::Global<v8::Symbol>,
+    primop_metadata: v8::Global<v8::Symbol>,
+    has_context: v8::Global<v8::Symbol>,
+    is_path: v8::Global<v8::Symbol>,
+    is_cycle: v8::Global<v8::Symbol>,
+}
+
+impl GlobalSymbols {
+    fn local<'a>(&self, scope: &ScopeRef<'a, '_>) -> LocalSymbols<'a> {
+        LocalSymbols {
+            is_thunk: v8::Local::new(scope, &self.is_thunk),
+            primop_metadata: v8::Local::new(scope, &self.primop_metadata),
+            has_context: v8::Local::new(scope, &self.has_context),
+            is_path: v8::Local::new(scope, &self.is_path),
+            is_cycle: v8::Local::new(scope, &self.is_cycle),
+        }
+    }
+}
+
+struct LocalSymbols<'a> {
+    is_thunk: v8::Local<'a, v8::Symbol>,
+    primop_metadata: v8::Local<'a, v8::Symbol>,
+    has_context: v8::Local<'a, v8::Symbol>,
+    is_path: v8::Local<'a, v8::Symbol>,
+    is_cycle: v8::Local<'a, v8::Symbol>,
+}
+
+struct CachedFunctions {
+    exec_bytecode: v8::Global<v8::Function>,
+    force_fn: v8::Global<v8::Function>,
+    force_shallow_fn: v8::Global<v8::Function>,
+    force_deep_fn: v8::Global<v8::Function>,
+    strings_array: v8::Global<v8::Array>,
+    constants_array: v8::Global<v8::Array>,
+}
+
+pub(crate) enum ForceMode {
+    Force,
+    ForceShallow,
+    ForceDeep,
+}
+
+fn sync_global_tables<Ctx: RuntimeContext>(
+    scope: &ScopeRef,
+    cached: &CachedFunctions,
+    ctx: &mut Ctx,
+) {
+    let (new_strings, new_constants, strings_base, constants_base) = ctx.get_unsynced();
+
+    if !new_strings.is_empty() {
+        let s_array = v8::Local::new(scope, &cached.strings_array);
+        for (i, s) in new_strings.iter().enumerate() {
+            let idx = (strings_base + i) as u32;
+            #[allow(clippy::unwrap_used)]
+            let val = v8::String::new(scope, s).unwrap();
+            s_array.set_index(scope, idx, val.into());
+        }
+    }
+
+    if !new_constants.is_empty() {
+        let k_array = v8::Local::new(scope, &cached.constants_array);
+        for (i, c) in new_constants.iter().enumerate() {
+            let idx = (constants_base + i) as u32;
+            let val: v8::Local<v8::Value> = match c {
+                Constant::Int(n) => v8::BigInt::new_from_i64(scope, *n).into(),
+                Constant::Float(bits) => v8::Number::new(scope, f64::from_bits(*bits)).into(),
+            };
+            k_array.set_index(scope, idx, val);
+        }
    }
 }

 fn to_value<'a>(
    val: LocalValue<'a>,
    scope: &ScopeRef<'a, '_>,
-    is_thunk_symbol: LocalSymbol<'a>,
-    primop_metadata_symbol: LocalSymbol<'a>,
-    has_context_symbol: LocalSymbol<'a>,
-    is_path_symbol: LocalSymbol<'a>,
-    is_cycle_symbol: LocalSymbol<'a>,
+    symbols: &LocalSymbols<'a>,
 ) -> Value {
    match () {
        _ if val.is_big_int() => {
@@ -283,40 +519,51 @@ fn to_value<'a>(
            let list = (0..len)
                .map(|i| {
                    let val = val.get_index(scope, i).expect("infallible index operation");
-                    to_value(
-                        val,
-                        scope,
-                        is_thunk_symbol,
-                        primop_metadata_symbol,
-                        has_context_symbol,
-                        is_path_symbol,
-                        is_cycle_symbol,
-                    )
+                    to_value(val, scope, symbols)
                })
                .collect();
            Value::List(List::new(list))
        }
        _ if val.is_function() => {
-            if let Some(primop) = to_primop(val, scope, primop_metadata_symbol) {
+            if let Some(primop) = to_primop(val, scope, symbols.primop_metadata) {
                primop
            } else {
                Value::Func
            }
        }
+        _ if val.is_map() => {
+            let val = val.try_cast::<v8::Map>().expect("infallible conversion");
+            let size = val.size() as u32;
+            let array = val.as_array(scope);
+            let attrs = (0..size)
+                .map(|i| {
+                    let key = array
+                        .get_index(scope, i * 2)
+                        .expect("infallible index operation");
+                    let key = key.to_rust_string_lossy(scope);
+                    let val = array
+                        .get_index(scope, i * 2 + 1)
+                        .expect("infallible index operation");
+                    let val = to_value(val, scope, symbols);
+                    (Symbol::new(Cow::Owned(key)), val)
+                })
+                .collect();
+            Value::AttrSet(AttrSet::new(attrs))
+        }
        _ if val.is_object() => {
-            if is_thunk(val, scope, is_thunk_symbol) {
+            if is_thunk(val, scope, symbols.is_thunk) {
                return Value::Thunk;
            }

-            if is_cycle(val, scope, is_cycle_symbol) {
+            if is_cycle(val, scope, symbols.is_cycle) {
                return Value::Repeated;
            }

-            if let Some(path_val) = extract_path(val, scope, is_path_symbol) {
+            if let Some(path_val) = extract_path(val, scope, symbols.is_path) {
                return Value::Path(path_val);
            }

-            if let Some(string_val) = extract_string_with_context(val, scope, has_context_symbol) {
+            if let Some(string_val) = extract_string_with_context(val, scope, symbols.has_context) {
                return Value::String(string_val);
            }

@@ -332,18 +579,7 @@ fn to_value<'a>(
                        .expect("infallible index operation");
                    let val = val.get(scope, key).expect("infallible operation");
                    let key = key.to_rust_string_lossy(scope);
-                    (
-                        Symbol::from(key),
-                        to_value(
-                            val,
-                            scope,
-                            is_thunk_symbol,
-                            primop_metadata_symbol,
-                            has_context_symbol,
-                            is_path_symbol,
-                            is_cycle_symbol,
-                        ),
-                    )
+                    (Symbol::from(key), to_value(val, scope, symbols))
                })
                .collect();
            Value::AttrSet(AttrSet::new(attrs))
--- a/nix-js/src/runtime/inspector.rs
+++ b/nix-js/src/runtime/inspector.rs
@@ -0,0 +1,493 @@
+// Copyright 2018-2025 the Deno authors. MIT license.
+
+// Alias for the future `!` type.
+use core::convert::Infallible as Never;
+use std::cell::RefCell;
+use std::net::SocketAddr;
+use std::pin::pin;
+use std::process;
+use std::rc::Rc;
+use std::task::Poll;
+use std::thread;
+
+use deno_core::InspectorMsg;
+use deno_core::InspectorSessionChannels;
+use deno_core::InspectorSessionKind;
+use deno_core::InspectorSessionProxy;
+use deno_core::JsRuntimeInspector;
+use deno_core::anyhow::Context;
+use deno_core::futures::channel::mpsc;
+use deno_core::futures::channel::mpsc::UnboundedReceiver;
+use deno_core::futures::channel::mpsc::UnboundedSender;
+use deno_core::futures::channel::oneshot;
+use deno_core::futures::prelude::*;
+use deno_core::futures::stream::StreamExt;
+use deno_core::serde_json::Value;
+use deno_core::serde_json::json;
+use deno_core::unsync::spawn;
+use deno_core::url::Url;
+use fastwebsockets::Frame;
+use fastwebsockets::OpCode;
+use fastwebsockets::WebSocket;
+use hashbrown::HashMap;
+use hyper::body::Bytes;
+use hyper_util::rt::TokioIo;
+use tokio::net::TcpListener;
+use tokio::sync::broadcast;
+use uuid::Uuid;
+
+/// Websocket server that is used to proxy connections from
+/// devtools to the inspector.
+pub struct InspectorServer {
+    pub host: SocketAddr,
+    register_inspector_tx: UnboundedSender<InspectorInfo>,
+    shutdown_server_tx: Option<broadcast::Sender<()>>,
+    thread_handle: Option<thread::JoinHandle<()>>,
+}
+
+impl InspectorServer {
+    pub fn new(host: SocketAddr, name: &'static str) -> Result<Self, anyhow::Error> {
+        let (register_inspector_tx, register_inspector_rx) = mpsc::unbounded::<InspectorInfo>();
+
+        let (shutdown_server_tx, shutdown_server_rx) = broadcast::channel(1);
+
+        let tcp_listener = std::net::TcpListener::bind(host)
+            .with_context(|| format!("Failed to bind inspector server socket at {}", host))?;
+        tcp_listener.set_nonblocking(true)?;
+
+        let thread_handle = thread::spawn(move || {
+            let rt = tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .expect("failed to build tokio runtime");
+            let local = tokio::task::LocalSet::new();
+            local.block_on(
+                &rt,
+                server(
+                    tcp_listener,
+                    register_inspector_rx,
+                    shutdown_server_rx,
+                    name,
+                ),
+            )
+        });
+
+        Ok(Self {
+            host,
+            register_inspector_tx,
+            shutdown_server_tx: Some(shutdown_server_tx),
+            thread_handle: Some(thread_handle),
+        })
+    }
+
+    pub fn register_inspector(
+        &self,
+        module_url: String,
+        inspector: Rc<JsRuntimeInspector>,
+        wait_for_session: bool,
+    ) {
+        let session_sender = inspector.get_session_sender();
+        let deregister_rx = inspector.add_deregister_handler();
+
+        let info = InspectorInfo::new(
+            self.host,
+            session_sender,
+            deregister_rx,
+            module_url,
+            wait_for_session,
+        );
+        self.register_inspector_tx
+            .unbounded_send(info)
+            .expect("unreachable");
+    }
+}
+
+impl Drop for InspectorServer {
+    fn drop(&mut self) {
+        if let Some(shutdown_server_tx) = self.shutdown_server_tx.take() {
+            shutdown_server_tx
+                .send(())
+                .expect("unable to send shutdown signal");
+        }
+
+        if let Some(thread_handle) = self.thread_handle.take() {
+            thread_handle.join().expect("unable to join thread");
+        }
+    }
+}
+
+fn handle_ws_request(
+    req: http::Request<hyper::body::Incoming>,
+    inspector_map_rc: Rc<RefCell<HashMap<Uuid, InspectorInfo>>>,
+) -> http::Result<http::Response<Box<http_body_util::Full<Bytes>>>> {
+    let (parts, body) = req.into_parts();
+    let req = http::Request::from_parts(parts, ());
+
+    let maybe_uuid = req
+        .uri()
+        .path()
+        .strip_prefix("/ws/")
+        .and_then(|s| Uuid::parse_str(s).ok());
+
+    let Some(uuid) = maybe_uuid else {
+        return http::Response::builder()
+            .status(http::StatusCode::BAD_REQUEST)
+            .body(Box::new(Bytes::from("Malformed inspector UUID").into()));
+    };
+
+    // run in a block to not hold borrow to `inspector_map` for too long
+    let new_session_tx = {
+        let inspector_map = inspector_map_rc.borrow();
+        let maybe_inspector_info = inspector_map.get(&uuid);
+
+        let Some(info) = maybe_inspector_info else {
+            return http::Response::builder()
+                .status(http::StatusCode::NOT_FOUND)
+                .body(Box::new(Bytes::from("Invalid inspector UUID").into()));
+        };
+        info.new_session_tx.clone()
+    };
+    let (parts, _) = req.into_parts();
+    let mut req = http::Request::from_parts(parts, body);
+
+    let Ok((resp, upgrade_fut)) = fastwebsockets::upgrade::upgrade(&mut req) else {
+        return http::Response::builder()
+            .status(http::StatusCode::BAD_REQUEST)
+            .body(Box::new(
+                Bytes::from("Not a valid Websocket Request").into(),
+            ));
+    };
+
+    // spawn a task that will wait for websocket connection and then pump messages between
+    // the socket and inspector proxy
+    spawn(async move {
+        let websocket = match upgrade_fut.await {
+            Ok(w) => w,
+            Err(err) => {
+                eprintln!(
+                    "Inspector server failed to upgrade to WS connection: {:?}",
+                    err
+                );
+                return;
+            }
+        };
+
+        // The 'outbound' channel carries messages sent to the websocket.
+        let (outbound_tx, outbound_rx) = mpsc::unbounded();
+        // The 'inbound' channel carries messages received from the websocket.
+        let (inbound_tx, inbound_rx) = mpsc::unbounded();
+
+        let inspector_session_proxy = InspectorSessionProxy {
+            channels: InspectorSessionChannels::Regular {
+                tx: outbound_tx,
+                rx: inbound_rx,
+            },
+            kind: InspectorSessionKind::NonBlocking {
+                wait_for_disconnect: true,
+            },
+        };
+
+        eprintln!("Debugger session started.");
+        let _ = new_session_tx.unbounded_send(inspector_session_proxy);
+        pump_websocket_messages(websocket, inbound_tx, outbound_rx).await;
+    });
+
+    let (parts, _body) = resp.into_parts();
+    let resp = http::Response::from_parts(parts, Box::new(http_body_util::Full::new(Bytes::new())));
+    Ok(resp)
+}
+
+fn handle_json_request(
+    inspector_map: Rc<RefCell<HashMap<Uuid, InspectorInfo>>>,
+    host: Option<String>,
+) -> http::Result<http::Response<Box<http_body_util::Full<Bytes>>>> {
+    let data = inspector_map
+        .borrow()
+        .values()
+        .map(move |info| info.get_json_metadata(&host))
+        .collect::<Vec<_>>();
+    let body: http_body_util::Full<Bytes> =
+        Bytes::from(serde_json::to_string(&data).expect("unreachable")).into();
+    http::Response::builder()
+        .status(http::StatusCode::OK)
+        .header(http::header::CONTENT_TYPE, "application/json")
+        .body(Box::new(body))
+}
+
+fn handle_json_version_request(
+    version_response: Value,
+) -> http::Result<http::Response<Box<http_body_util::Full<Bytes>>>> {
+    let body = Box::new(http_body_util::Full::from(
+        serde_json::to_string(&version_response).expect("unreachable"),
+    ));
+
+    http::Response::builder()
+        .status(http::StatusCode::OK)
+        .header(http::header::CONTENT_TYPE, "application/json")
+        .body(body)
+}
+
+async fn server(
+    listener: std::net::TcpListener,
+    register_inspector_rx: UnboundedReceiver<InspectorInfo>,
+    shutdown_server_rx: broadcast::Receiver<()>,
+    name: &str,
+) {
+    let inspector_map_ = Rc::new(RefCell::new(HashMap::<Uuid, InspectorInfo>::new()));
+
+    let inspector_map = Rc::clone(&inspector_map_);
+    let register_inspector_handler =
+        listen_for_new_inspectors(register_inspector_rx, inspector_map.clone()).boxed_local();
+
+    let inspector_map = Rc::clone(&inspector_map_);
+    let deregister_inspector_handler = future::poll_fn(|cx| {
+        inspector_map
+            .borrow_mut()
+            .retain(|_, info| info.deregister_rx.poll_unpin(cx) == Poll::Pending);
+        Poll::<Never>::Pending
+    })
+    .boxed_local();
+
+    let json_version_response = json!({
+        "Browser": name,
+        "Protocol-Version": "1.3",
+        "V8-Version": deno_core::v8::VERSION_STRING,
+    });
+
+    // Create the server manually so it can use the Local Executor
+    let listener = match TcpListener::from_std(listener) {
+        Ok(l) => l,
+        Err(err) => {
+            eprintln!("Cannot create async listener from std listener: {:?}", err);
+            return;
+        }
+    };
+
+    let server_handler = async move {
+        loop {
+            let mut rx = shutdown_server_rx.resubscribe();
+            let mut shutdown_rx = pin!(rx.recv());
+            let mut accept = pin!(listener.accept());
+
+            let stream = tokio::select! {
+                accept_result =
+                    &mut accept => {
+                        match accept_result {
+                            Ok((s, _)) => s,
+                            Err(err) => {
+                                eprintln!("Failed to accept inspector connection: {:?}", err);
+                                continue;
+                            }
+                        }
+                    },
+
+                    _ = &mut shutdown_rx => {
+                        break;
+                    }
+            };
+            let io = TokioIo::new(stream);
+
+            let inspector_map = Rc::clone(&inspector_map_);
+            let json_version_response = json_version_response.clone();
+            let mut shutdown_server_rx = shutdown_server_rx.resubscribe();
+
+            let service =
+                hyper::service::service_fn(move |req: http::Request<hyper::body::Incoming>| {
+                    future::ready({
+                        // If the host header can make a valid URL, use it
+                        let host = req
+                            .headers()
+                            .get("host")
+                            .and_then(|host| host.to_str().ok())
+                            .and_then(|host| Url::parse(&format!("http://{host}")).ok())
+                            .and_then(|url| match (url.host(), url.port()) {
+                                (Some(host), Some(port)) => Some(format!("{host}:{port}")),
+                                (Some(host), None) => Some(format!("{host}")),
+                                _ => None,
+                            });
+                        match (req.method(), req.uri().path()) {
+                            (&http::Method::GET, path) if path.starts_with("/ws/") => {
+                                handle_ws_request(req, Rc::clone(&inspector_map))
+                            }
+                            (&http::Method::GET, "/json/version") => {
+                                handle_json_version_request(json_version_response.clone())
+                            }
+                            (&http::Method::GET, "/json") => {
+                                handle_json_request(Rc::clone(&inspector_map), host)
+                            }
+                            (&http::Method::GET, "/json/list") => {
+                                handle_json_request(Rc::clone(&inspector_map), host)
+                            }
+                            _ => http::Response::builder()
+                                .status(http::StatusCode::NOT_FOUND)
+                                .body(Box::new(http_body_util::Full::new(Bytes::from(
+                                    "Not Found",
+                                )))),
+                        }
+                    })
+                });
+
+            deno_core::unsync::spawn(async move {
+                let server = hyper::server::conn::http1::Builder::new();
+
+                let mut conn = pin!(server.serve_connection(io, service).with_upgrades());
+                let mut shutdown_rx = pin!(shutdown_server_rx.recv());
+
+                tokio::select! {
+                    result = conn.as_mut() => {
+                        if let Err(err) = result {
+                            eprintln!("Failed to serve connection: {:?}", err);
+                        }
+                    },
+                    _ = &mut shutdown_rx => {
+                        conn.as_mut().graceful_shutdown();
+                        let _ = conn.await;
+                    }
+                }
+            });
+        }
+    }
+    .boxed_local();
+
+    tokio::select! {
+        _ = register_inspector_handler => {},
+        _ = deregister_inspector_handler => unreachable!(),
+        _ = server_handler => {},
+    }
+}
+
+async fn listen_for_new_inspectors(
+    mut register_inspector_rx: UnboundedReceiver<InspectorInfo>,
+    inspector_map: Rc<RefCell<HashMap<Uuid, InspectorInfo>>>,
+) {
+    while let Some(info) = register_inspector_rx.next().await {
+        eprintln!(
+            "Debugger listening on {}",
+            info.get_websocket_debugger_url(&info.host.to_string())
+        );
+        eprintln!("Visit chrome://inspect to connect to the debugger.");
+        if info.wait_for_session {
+            eprintln!("nix-js is waiting for debugger to connect.");
+        }
+        if inspector_map.borrow_mut().insert(info.uuid, info).is_some() {
+            panic!("Inspector UUID already in map");
+        }
+    }
+}
+
+/// The pump future takes care of forwarding messages between the websocket
+/// and channels. It resolves when either side disconnects, ignoring any
+/// errors.
+///
+/// The future proxies messages sent and received on a WebSocket
+/// to a UnboundedSender/UnboundedReceiver pair. We need these "unbounded" channel ends to sidestep
+/// Tokio's task budget, which causes issues when JsRuntimeInspector::poll_sessions()
+/// needs to block the thread because JavaScript execution is paused.
+///
+/// This works because UnboundedSender/UnboundedReceiver are implemented in the
+/// 'futures' crate, therefore they can't participate in Tokio's cooperative
+/// task yielding.
+async fn pump_websocket_messages(
+    mut websocket: WebSocket<TokioIo<hyper::upgrade::Upgraded>>,
+    inbound_tx: UnboundedSender<String>,
+    mut outbound_rx: UnboundedReceiver<InspectorMsg>,
+) {
+    'pump: loop {
+        tokio::select! {
+            Some(msg) = outbound_rx.next() => {
+                let msg = Frame::text(msg.content.into_bytes().into());
+                let _ = websocket.write_frame(msg).await;
+            }
+            Ok(msg) = websocket.read_frame() => {
+                match msg.opcode {
+                    OpCode::Text => {
+                        if let Ok(s) = String::from_utf8(msg.payload.to_vec()) {
+                            let _ = inbound_tx.unbounded_send(s);
+                        }
+                    }
+                    OpCode::Close => {
+                        // Users don't care if there was an error coming from debugger,
+                        // just about the fact that debugger did disconnect.
+                        eprintln!("Debugger session ended");
+                        break 'pump;
+                    }
+                    _ => {
+                        // Ignore other messages.
+                    }
+                }
+            }
+            else => {
+                break 'pump;
+            }
+        }
+    }
+}
+
+/// Inspector information that is sent from the isolate thread to the server
+/// thread when a new inspector is created.
+pub struct InspectorInfo {
+    pub host: SocketAddr,
+    pub uuid: Uuid,
+    pub thread_name: Option<String>,
+    pub new_session_tx: UnboundedSender<InspectorSessionProxy>,
+    pub deregister_rx: oneshot::Receiver<()>,
+    pub url: String,
+    pub wait_for_session: bool,
+}
+
+impl InspectorInfo {
+    pub fn new(
+        host: SocketAddr,
+        new_session_tx: mpsc::UnboundedSender<InspectorSessionProxy>,
+        deregister_rx: oneshot::Receiver<()>,
+        url: String,
+        wait_for_session: bool,
+    ) -> Self {
+        Self {
+            host,
+            uuid: Uuid::new_v4(),
+            thread_name: thread::current().name().map(|n| n.to_owned()),
+            new_session_tx,
+            deregister_rx,
+            url,
+            wait_for_session,
+        }
+    }
+
+    fn get_json_metadata(&self, host: &Option<String>) -> Value {
+        let host_listen = format!("{}", self.host);
+        let host = host.as_ref().unwrap_or(&host_listen);
+        json!({
+            "description": "nix-js",
+            "devtoolsFrontendUrl": self.get_frontend_url(host),
+            "faviconUrl": "https://deno.land/favicon.ico",
+            "id": self.uuid.to_string(),
+            "title": self.get_title(),
+            "type": "node",
+            "url": self.url.to_string(),
+            "webSocketDebuggerUrl": self.get_websocket_debugger_url(host),
+        })
+    }
+
+    pub fn get_websocket_debugger_url(&self, host: &str) -> String {
+        format!("ws://{}/ws/{}", host, &self.uuid)
+    }
+
+    fn get_frontend_url(&self, host: &str) -> String {
+        format!(
+            "devtools://devtools/bundled/js_app.html?ws={}/ws/{}&experiments=true&v8only=true",
+            host, &self.uuid
+        )
+    }
+
+    fn get_title(&self) -> String {
+        format!(
+            "nix-js{} [pid: {}]",
+            self.thread_name
+                .as_ref()
+                .map(|n| format!(" - {n}"))
+                .unwrap_or_default(),
+            process::id(),
+        )
+    }
+}
--- a/nix-js/src/runtime/ops.rs
+++ b/nix-js/src/runtime/ops.rs
--- a/nix-js/src/store.rs
+++ b/nix-js/src/store.rs
@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 use crate::error::Result;

 mod config;
@@ -39,12 +37,4 @@ pub trait Store: Send + Sync {
        content: &str,
        references: Vec<String>,
    ) -> Result<String>;
-
-    fn make_fixed_output_path(
-        &self,
-        hash_algo: &str,
-        hash: &str,
-        hash_mode: &str,
-        name: &str,
-    ) -> Result<String>;
 }
--- a/nix-js/src/store/daemon.rs
+++ b/nix-js/src/store/daemon.rs
@@ -87,11 +87,12 @@ impl Store for DaemonStore {
        recursive: bool,
        references: Vec<String>,
    ) -> Result<String> {
+        use std::fs;
+
        use nix_compat::nix_daemon::types::AddToStoreNarRequest;
        use nix_compat::nixhash::{CAHash, NixHash};
        use nix_compat::store_path::{StorePath, build_ca_path};
        use sha2::{Digest, Sha256};
-        use std::fs;
        use tempfile::NamedTempFile;

        let temp_file = NamedTempFile::new()
@@ -237,11 +238,12 @@ impl Store for DaemonStore {
        content: &str,
        references: Vec<String>,
    ) -> Result<String> {
+        use std::fs;
+
        use nix_compat::nix_daemon::types::AddToStoreNarRequest;
        use nix_compat::nixhash::CAHash;
        use nix_compat::store_path::{StorePath, build_text_path};
        use sha2::{Digest, Sha256};
-        use std::fs;
        use tempfile::NamedTempFile;

        let temp_file = NamedTempFile::new()
@@ -304,51 +306,6 @@ impl Store for DaemonStore {

        Ok(store_path_str)
    }
-
-    fn make_fixed_output_path(
-        &self,
-        hash_algo: &str,
-        hash: &str,
-        hash_mode: &str,
-        name: &str,
-    ) -> Result<String> {
-        use nix_compat::nixhash::{CAHash, NixHash};
-        use nix_compat::store_path::build_ca_path;
-
-        let nix_hash = match hash_algo {
-            "sha256" => {
-                let hash_bytes = hex::decode(hash)
-                    .map_err(|e| Error::internal(format!("Invalid hash hex: {}", e)))?;
-                if hash_bytes.len() != 32 {
-                    return Err(Error::internal(format!(
-                        "Invalid sha256 hash length: expected 32, got {}",
-                        hash_bytes.len()
-                    )));
-                }
-                let mut arr = [0u8; 32];
-                arr.copy_from_slice(&hash_bytes);
-                NixHash::Sha256(arr)
-            }
-            _ => {
-                return Err(Error::internal(format!(
-                    "Unsupported hash algorithm: {}",
-                    hash_algo
-                )));
-            }
-        };
-
-        let ca_hash = if hash_mode == "r" {
-            CAHash::Nar(nix_hash)
-        } else {
-            CAHash::Flat(nix_hash)
-        };
-
-        let store_path: nix_compat::store_path::StorePath<String> =
-            build_ca_path(name, &ca_hash, Vec::<String>::new(), false)
-                .map_err(|e| Error::internal(format!("Failed to build store path: {}", e)))?;
-
-        Ok(store_path.to_absolute_path())
-    }
 }

 const PROTOCOL_VERSION: ProtocolVersion = ProtocolVersion::from_parts(1, 37);
@@ -585,6 +542,7 @@ impl NixDaemonClient {
    }

    /// Query information about a store path
+    #[allow(dead_code)]
    pub async fn query_path_info(&mut self, path: &str) -> IoResult<Option<UnkeyedValidPathInfo>> {
        let store_path = StorePath::<String>::from_absolute_path(path.as_bytes())
            .map_err(|e| IoError::new(IoErrorKind::InvalidInput, e.to_string()))?;
@@ -658,6 +616,7 @@ impl NixDaemonClient {
    }

    /// Query which paths are valid
+    #[allow(dead_code)]
    pub async fn query_valid_paths(&mut self, paths: Vec<String>) -> IoResult<Vec<String>> {
        let store_paths: IoResult<Vec<StorePath<String>>> = paths
            .iter()
@@ -762,6 +721,7 @@ impl NixDaemonConnection {
    }

    /// Query information about a store path
+    #[allow(dead_code)]
    pub async fn query_path_info(&self, path: &str) -> IoResult<Option<UnkeyedValidPathInfo>> {
        let mut client = self.client.lock().await;
        client.query_path_info(path).await
@@ -774,6 +734,7 @@ impl NixDaemonConnection {
    }

    /// Query which paths are valid
+    #[allow(dead_code)]
    pub async fn query_valid_paths(&self, paths: Vec<String>) -> IoResult<Vec<String>> {
        let mut client = self.client.lock().await;
        client.query_valid_paths(paths).await
--- a/nix-js/src/store/error.rs
+++ b/nix-js/src/store/error.rs
@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use std::fmt;

 #[derive(Debug)]
--- a/nix-js/src/store/validation.rs
+++ b/nix-js/src/store/validation.rs
@@ -81,7 +81,7 @@ pub fn validate_store_path(store_dir: &str, path: &str) -> Result<()> {
 mod tests {
    use super::*;

-    #[test]
+    #[test_log::test]
    fn test_valid_store_paths() {
        let store_dir = "/nix/store";
        let valid_paths = vec![
@@ -100,7 +100,7 @@ mod tests {
        }
    }

-    #[test]
+    #[test_log::test]
    fn test_invalid_store_paths() {
        let store_dir = "/nix/store";
        let invalid_paths = vec![
--- a/nix-js/src/string_context.rs
+++ b/nix-js/src/string_context.rs
@@ -0,0 +1,209 @@
+use std::collections::{BTreeMap, BTreeSet, VecDeque};
+
+pub enum StringContextElem {
+    Opaque { path: String },
+    DrvDeep { drv_path: String },
+    Built { drv_path: String, output: String },
+}
+
+impl StringContextElem {
+    pub fn decode(encoded: &str) -> Self {
+        if let Some(drv_path) = encoded.strip_prefix('=') {
+            StringContextElem::DrvDeep {
+                drv_path: drv_path.to_string(),
+            }
+        } else if let Some(rest) = encoded.strip_prefix('!') {
+            if let Some(second_bang) = rest.find('!') {
+                let output = rest[..second_bang].to_string();
+                let drv_path = rest[second_bang + 1..].to_string();
+                StringContextElem::Built { drv_path, output }
+            } else {
+                StringContextElem::Opaque {
+                    path: encoded.to_string(),
+                }
+            }
+        } else {
+            StringContextElem::Opaque {
+                path: encoded.to_string(),
+            }
+        }
+    }
+}
+
+pub type InputDrvs = BTreeMap<String, BTreeSet<String>>;
+pub type Srcs = BTreeSet<String>;
+pub fn extract_input_drvs_and_srcs(context: &[String]) -> Result<(InputDrvs, Srcs), String> {
+    let mut input_drvs: BTreeMap<String, BTreeSet<String>> = BTreeMap::new();
+    let mut input_srcs: BTreeSet<String> = BTreeSet::new();
+
+    for encoded in context {
+        match StringContextElem::decode(encoded) {
+            StringContextElem::Opaque { path } => {
+                input_srcs.insert(path);
+            }
+            StringContextElem::DrvDeep { drv_path } => {
+                compute_fs_closure(&drv_path, &mut input_drvs, &mut input_srcs)?;
+            }
+            StringContextElem::Built { drv_path, output } => {
+                input_drvs.entry(drv_path).or_default().insert(output);
+            }
+        }
+    }
+
+    Ok((input_drvs, input_srcs))
+}
+
+fn compute_fs_closure(
+    drv_path: &str,
+    input_drvs: &mut BTreeMap<String, BTreeSet<String>>,
+    input_srcs: &mut BTreeSet<String>,
+) -> Result<(), String> {
+    let mut queue: VecDeque<String> = VecDeque::new();
+    let mut visited: BTreeSet<String> = BTreeSet::new();
+
+    queue.push_back(drv_path.to_string());
+
+    while let Some(current_path) = queue.pop_front() {
+        if visited.contains(&current_path) {
+            continue;
+        }
+        visited.insert(current_path.clone());
+        input_srcs.insert(current_path.clone());
+
+        if !current_path.ends_with(".drv") {
+            continue;
+        }
+
+        let content = std::fs::read_to_string(&current_path)
+            .map_err(|e| format!("failed to read derivation {}: {}", current_path, e))?;
+
+        let inputs = parse_derivation_inputs(&content)
+            .ok_or_else(|| format!("failed to parse derivation {}", current_path))?;
+
+        for src in inputs.input_srcs {
+            input_srcs.insert(src.clone());
+            if !visited.contains(&src) {
+                queue.push_back(src);
+            }
+        }
+
+        for (dep_drv, outputs) in inputs.input_drvs {
+            input_srcs.insert(dep_drv.clone());
+            let entry = input_drvs.entry(dep_drv.clone()).or_default();
+            for output in outputs {
+                entry.insert(output);
+            }
+            if !visited.contains(&dep_drv) {
+                queue.push_back(dep_drv);
+            }
+        }
+    }
+
+    Ok(())
+}
+
+struct DerivationInputs {
+    input_drvs: Vec<(String, Vec<String>)>,
+    input_srcs: Vec<String>,
+}
+
+fn parse_derivation_inputs(aterm: &str) -> Option<DerivationInputs> {
+    let aterm = aterm.strip_prefix("Derive([")?;
+
+    let mut bracket_count: i32 = 1;
+    let mut pos = 0;
+    let bytes = aterm.as_bytes();
+    while pos < bytes.len() && bracket_count > 0 {
+        match bytes[pos] {
+            b'[' => bracket_count += 1,
+            b']' => bracket_count -= 1,
+            _ => {}
+        }
+        pos += 1;
+    }
+    if bracket_count != 0 {
+        return None;
+    }
+
+    let rest = &aterm[pos..];
+    let rest = rest.strip_prefix(",[")?;
+
+    let mut input_drvs = Vec::new();
+    let mut bracket_count: i32 = 1;
+    let mut start = 0;
+    pos = 0;
+    let bytes = rest.as_bytes();
+
+    while pos < bytes.len() && bracket_count > 0 {
+        match bytes[pos] {
+            b'[' => bracket_count += 1,
+            b']' => bracket_count -= 1,
+            b'(' if bracket_count == 1 => {
+                start = pos;
+            }
+            b')' if bracket_count == 1 => {
+                let entry = &rest[start + 1..pos];
+                if let Some((drv_path, outputs)) = parse_input_drv_entry(entry) {
+                    input_drvs.push((drv_path, outputs));
+                }
+            }
+            _ => {}
+        }
+        pos += 1;
+    }
+
+    let rest = &rest[pos..];
+    let rest = rest.strip_prefix(",[")?;
+
+    let mut input_srcs = Vec::new();
+    bracket_count = 1;
+    pos = 0;
+    let bytes = rest.as_bytes();
+
+    while pos < bytes.len() && bracket_count > 0 {
+        match bytes[pos] {
+            b'[' => bracket_count += 1,
+            b']' => bracket_count -= 1,
+            b'"' if bracket_count == 1 => {
+                pos += 1;
+                let src_start = pos;
+                while pos < bytes.len() && bytes[pos] != b'"' {
+                    if bytes[pos] == b'\\' && pos + 1 < bytes.len() {
+                        pos += 2;
+                    } else {
+                        pos += 1;
+                    }
+                }
+                let src = std::str::from_utf8(&bytes[src_start..pos]).ok()?;
+                input_srcs.push(src.to_string());
+            }
+            _ => {}
+        }
+        pos += 1;
+    }
+
+    Some(DerivationInputs {
+        input_drvs,
+        input_srcs,
+    })
+}
+
+fn parse_input_drv_entry(entry: &str) -> Option<(String, Vec<String>)> {
+    let entry = entry.strip_prefix('"')?;
+    let quote_end = entry.find('"')?;
+    let drv_path = entry[..quote_end].to_string();
+
+    let rest = &entry[quote_end + 1..];
+    let rest = rest.strip_prefix(",[")?;
+    let rest = rest.strip_suffix(']')?;
+
+    let mut outputs = Vec::new();
+    for part in rest.split(',') {
+        let part = part.trim();
+        if let Some(name) = part.strip_prefix('"').and_then(|s| s.strip_suffix('"')) {
+            outputs.push(name.to_string());
+        }
+    }
+
+    Some((drv_path, outputs))
+}
--- a/nix-js/src/value.rs
+++ b/nix-js/src/value.rs
@@ -1,7 +1,6 @@
 use core::fmt::{Debug, Display, Formatter, Result as FmtResult};
 use core::hash::Hash;
 use core::ops::Deref;
-
 use std::borrow::Cow;
 use std::collections::BTreeMap;
 use std::ops::DerefMut;
--- a/nix-js/tests/lang/eval-okay-intersectAttrs.exp
+++ b/nix-js/tests/lang/eval-okay-intersectAttrs.exp
@@ -1 +0,0 @@
-[ { } { a = 1; } { a = 1; } { a = "a"; } { m = 1; } { m = "m"; } { n = 1; } { n = "n"; } { n = 1; p = 2; } { n = "n"; p = "p"; } { n = 1; p = 2; } { n = "n"; p = "p"; } { a = "a"; b = "b"; c = "c"; d = "d"; e = "e"; f = "f"; g = "g"; h = "h"; i = "i"; j = "j"; k = "k"; l = "l"; m = "m"; n = "n"; o = "o"; p = "p"; q = "q"; r = "r"; s = "s"; t = "t"; u = "u"; v = "v"; w = "w"; x = "x"; y = "y"; z = "z"; } true ]
--- a/nix-js/tests/lang/eval-okay-print.exp
+++ b/nix-js/tests/lang/eval-okay-print.exp
@@ -1 +0,0 @@
-[ null <PRIMOP> <PRIMOP-APP> <LAMBDA> [ [ «repeated» ] ] ]
--- a/nix-js/tests/tests/basic_eval.rs
+++ b/nix-js/tests/tests/basic_eval.rs
@@ -1,36 +1,33 @@
-mod utils;
-
 use nix_js::value::Value;
-use utils::eval;

-use crate::utils::eval_result;
+use crate::utils::{eval, eval_result};

-#[test]
+#[test_log::test]
 fn arithmetic() {
    assert_eq!(eval("1 + 1"), Value::Int(2));
 }

-#[test]
+#[test_log::test]
 fn simple_function_application() {
    assert_eq!(eval("(x: x) 1"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn curried_function() {
    assert_eq!(eval("(x: y: x - y) 2 1"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn rec_attrset() {
    assert_eq!(eval("rec { b = a; a = 1; }.b"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn let_binding() {
    assert_eq!(eval("let b = a; a = 1; in b"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn fibonacci() {
    assert_eq!(
        eval(
@@ -40,7 +37,7 @@ fn fibonacci() {
    );
 }

-#[test]
+#[test_log::test]
 fn fixed_point_combinator() {
    assert_eq!(
        eval("((f: let x = f x; in x)(self: { x = 1; y = self.x + 1; })).y"),
@@ -48,17 +45,17 @@ fn fixed_point_combinator() {
    );
 }

-#[test]
+#[test_log::test]
 fn conditional_true() {
    assert_eq!(eval("if true then 1 else 0"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn conditional_false() {
    assert_eq!(eval("if false then 1 else 0"), Value::Int(0));
 }

-#[test]
+#[test_log::test]
 fn nested_let() {
    assert_eq!(
        eval("let x = 1; in let y = x + 1; z = y + 1; in z"),
@@ -66,7 +63,7 @@ fn nested_let() {
    );
 }

-#[test]
+#[test_log::test]
 fn rec_inherit_fails() {
    assert!(eval_result("{ inherit x; }").is_err());
 }
--- a/nix-js/tests/tests/builtins.rs
+++ b/nix-js/tests/tests/builtins.rs
@@ -1,33 +1,32 @@
-mod utils;
-
 use std::collections::BTreeMap;

 use nix_js::value::{AttrSet, List, Value};
-use utils::eval;

-#[test]
+use crate::utils::eval;
+
+#[test_log::test]
 fn builtins_accessible() {
    let result = eval("builtins");
    assert!(matches!(result, Value::AttrSet(_)));
 }

-#[test]
+#[test_log::test]
 fn builtins_self_reference() {
    let result = eval("builtins.builtins");
    assert!(matches!(result, Value::AttrSet(_)));
 }

-#[test]
+#[test_log::test]
 fn builtins_add() {
    assert_eq!(eval("builtins.add 1 2"), Value::Int(3));
 }

-#[test]
+#[test_log::test]
 fn builtins_length() {
    assert_eq!(eval("builtins.length [1 2 3]"), Value::Int(3));
 }

-#[test]
+#[test_log::test]
 fn builtins_map() {
    assert_eq!(
        eval("builtins.map (x: x * 2) [1 2 3]"),
@@ -35,7 +34,7 @@ fn builtins_map() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_filter() {
    assert_eq!(
        eval("builtins.filter (x: x > 1) [1 2 3]"),
@@ -43,7 +42,7 @@ fn builtins_filter() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_attrnames() {
    let result = eval("builtins.attrNames { a = 1; b = 2; }");
    assert!(matches!(result, Value::List(_)));
@@ -52,12 +51,12 @@ fn builtins_attrnames() {
    }
 }

-#[test]
+#[test_log::test]
 fn builtins_head() {
    assert_eq!(eval("builtins.head [1 2 3]"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn builtins_tail() {
    assert_eq!(
        eval("builtins.tail [1 2 3]"),
@@ -65,17 +64,17 @@ fn builtins_tail() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_in_let() {
    assert_eq!(eval("let b = builtins; in b.add 5 3"), Value::Int(8));
 }

-#[test]
+#[test_log::test]
 fn builtins_in_with() {
    assert_eq!(eval("with builtins; add 10 20"), Value::Int(30));
 }

-#[test]
+#[test_log::test]
 fn builtins_nested_calls() {
    assert_eq!(
        eval("builtins.add (builtins.mul 2 3) (builtins.sub 10 5)"),
@@ -83,32 +82,32 @@ fn builtins_nested_calls() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_is_list() {
    assert_eq!(eval("builtins.isList [1 2 3]"), Value::Bool(true));
 }

-#[test]
+#[test_log::test]
 fn builtins_is_attrs() {
    assert_eq!(eval("builtins.isAttrs { a = 1; }"), Value::Bool(true));
 }

-#[test]
+#[test_log::test]
 fn builtins_is_function() {
    assert_eq!(eval("builtins.isFunction (x: x)"), Value::Bool(true));
 }

-#[test]
+#[test_log::test]
 fn builtins_is_null() {
    assert_eq!(eval("builtins.isNull null"), Value::Bool(true));
 }

-#[test]
+#[test_log::test]
 fn builtins_is_bool() {
    assert_eq!(eval("builtins.isBool true"), Value::Bool(true));
 }

-#[test]
+#[test_log::test]
 fn builtins_shadowing() {
    assert_eq!(
        eval("let builtins = { add = x: y: x - y; }; in builtins.add 5 3"),
@@ -116,13 +115,13 @@ fn builtins_shadowing() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_lazy_evaluation() {
    let result = eval("builtins.builtins.builtins.add 1 1");
    assert_eq!(result, Value::Int(2));
 }

-#[test]
+#[test_log::test]
 fn builtins_foldl() {
    assert_eq!(
        eval("builtins.foldl' (acc: x: acc + x) 0 [1 2 3 4 5]"),
@@ -130,13 +129,13 @@ fn builtins_foldl() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_elem() {
    assert_eq!(eval("builtins.elem 2 [1 2 3]"), Value::Bool(true));
    assert_eq!(eval("builtins.elem 5 [1 2 3]"), Value::Bool(false));
 }

-#[test]
+#[test_log::test]
 fn builtins_concat_lists() {
    assert_eq!(
        eval("builtins.concatLists [[1 2] [3 4] [5]]"),
@@ -150,7 +149,7 @@ fn builtins_concat_lists() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_basic() {
    assert_eq!(
        eval("builtins.compareVersions \"1.0\" \"2.3\""),
@@ -174,7 +173,7 @@ fn builtins_compare_versions_basic() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_components() {
    assert_eq!(
        eval("builtins.compareVersions \"2.3.1\" \"2.3\""),
@@ -186,7 +185,7 @@ fn builtins_compare_versions_components() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_numeric_vs_alpha() {
    // Numeric component comes before alpha component
    assert_eq!(
@@ -199,7 +198,7 @@ fn builtins_compare_versions_numeric_vs_alpha() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_pre() {
    // "pre" is special: comes before everything except another "pre"
    assert_eq!(
@@ -220,7 +219,7 @@ fn builtins_compare_versions_pre() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_alpha() {
    // Alphabetic comparison
    assert_eq!(
@@ -233,7 +232,7 @@ fn builtins_compare_versions_alpha() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_symmetry() {
    // Test symmetry: compareVersions(a, b) == -compareVersions(b, a)
    assert_eq!(
@@ -246,7 +245,7 @@ fn builtins_compare_versions_symmetry() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_compare_versions_complex() {
    // Complex version strings with multiple components
    assert_eq!(
@@ -263,7 +262,7 @@ fn builtins_compare_versions_complex() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_generic_closure() {
    assert_eq!(
        eval(
@@ -279,7 +278,7 @@ fn builtins_generic_closure() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_function_args() {
    assert_eq!(
        eval("builtins.functionArgs (x: 1)"),
@@ -316,7 +315,7 @@ fn builtins_function_args() {
    );
 }

-#[test]
+#[test_log::test]
 fn builtins_parse_drv_name() {
    let result = eval(r#"builtins.parseDrvName "nix-js-0.1.0pre""#).unwrap_attr_set();
    assert_eq!(result.get("name"), Some(&Value::String("nix-js".into())));
--- a/nix-js/tests/tests/builtins_store.rs
+++ b/nix-js/tests/tests/builtins_store.rs
@@ -1,9 +1,8 @@
-mod utils;
-
 use nix_js::value::Value;
-use utils::eval_result;

-#[test]
+use crate::utils::eval_result;
+
+#[test_log::test]
 fn to_file_simple() {
    let result =
        eval_result(r#"builtins.toFile "hello.txt" "Hello, World!""#).expect("Failed to evaluate");
@@ -20,7 +19,7 @@ fn to_file_simple() {
    }
 }

-#[test]
+#[test_log::test]
 fn to_file_with_references() {
    let result = eval_result(
        r#"
@@ -43,7 +42,7 @@ fn to_file_with_references() {
    }
 }

-#[test]
+#[test_log::test]
 fn to_file_invalid_name_with_slash() {
    let result = eval_result(r#"builtins.toFile "foo/bar.txt" "content""#);

@@ -56,7 +55,7 @@ fn to_file_invalid_name_with_slash() {
    );
 }

-#[test]
+#[test_log::test]
 fn to_file_invalid_name_dot() {
    let result = eval_result(r#"builtins.toFile "." "content""#);

@@ -64,7 +63,7 @@ fn to_file_invalid_name_dot() {
    assert!(result.unwrap_err().to_string().contains("invalid name"));
 }

-#[test]
+#[test_log::test]
 fn to_file_invalid_name_dotdot() {
    let result = eval_result(r#"builtins.toFile ".." "content""#);

@@ -72,7 +71,7 @@ fn to_file_invalid_name_dotdot() {
    assert!(result.unwrap_err().to_string().contains("invalid name"));
 }

-#[test]
+#[test_log::test]
 fn store_path_validation_not_in_store() {
    let result = eval_result(r#"builtins.storePath "/tmp/foo""#);

@@ -85,7 +84,7 @@ fn store_path_validation_not_in_store() {
    );
 }

-#[test]
+#[test_log::test]
 fn store_path_validation_malformed_hash() {
    let dummy_file_result = eval_result(r#"builtins.toFile "dummy.txt" "content""#)
        .expect("Failed to create dummy file");
@@ -113,7 +112,7 @@ fn store_path_validation_malformed_hash() {
    );
 }

-#[test]
+#[test_log::test]
 fn store_path_validation_missing_name() {
    let dummy_file_result = eval_result(r#"builtins.toFile "dummy.txt" "content""#)
        .expect("Failed to create dummy file");
@@ -141,7 +140,7 @@ fn store_path_validation_missing_name() {
    );
 }

-#[test]
+#[test_log::test]
 fn to_file_curried_application() {
    let result = eval_result(
        r#"
@@ -163,7 +162,7 @@ fn to_file_curried_application() {
    }
 }

-#[test]
+#[test_log::test]
 fn to_file_number_conversion() {
    let result = eval_result(r#"builtins.toFile "number.txt" (builtins.toString 42)"#)
        .expect("Failed to evaluate");
@@ -177,7 +176,7 @@ fn to_file_number_conversion() {
    }
 }

-#[test]
+#[test_log::test]
 fn to_file_list_conversion() {
    let result = eval_result(
        r#"builtins.toFile "list.txt" (builtins.concatStringsSep "\n" ["line1" "line2" "line3"])"#,
--- a/nix-js/tests/tests/derivation.rs
+++ b/nix-js/tests/tests/derivation.rs
@@ -1,9 +1,8 @@
-mod utils;
-
 use nix_js::value::Value;
-use utils::{eval_deep, eval_deep_result};

-#[test]
+use crate::utils::{eval_deep, eval_deep_result};
+
+#[test_log::test]
 fn add_operator_preserves_derivation_context() {
    let result = eval_deep(
        r#"
@@ -39,7 +38,7 @@ fn add_operator_preserves_derivation_context() {
    assert_eq!(result, nix_result);
 }

-#[test]
+#[test_log::test]
 fn derivation_minimal() {
    let result = eval_deep(
        r#"derivation { name = "hello"; builder = "/bin/sh"; system = "x86_64-linux"; }"#,
@@ -77,7 +76,7 @@ fn derivation_minimal() {
    }
 }

-#[test]
+#[test_log::test]
 fn derivation_with_args() {
    let result = eval_deep(
        r#"derivation {
@@ -99,7 +98,7 @@ fn derivation_with_args() {
    }
 }

-#[test]
+#[test_log::test]
 fn derivation_to_string() {
    let result = eval_deep(
        r#"toString (derivation { name = "foo"; builder = "/bin/sh"; system = "x86_64-linux"; })"#,
@@ -111,7 +110,7 @@ fn derivation_to_string() {
    }
 }

-#[test]
+#[test_log::test]
 fn derivation_missing_name() {
    let result =
        eval_deep_result(r#"derivation { builder = "/bin/sh"; system = "x86_64-linux"; }"#);
@@ -121,7 +120,7 @@ fn derivation_missing_name() {
    assert!(err_msg.contains("missing required attribute 'name'"));
 }

-#[test]
+#[test_log::test]
 fn derivation_invalid_name_with_drv_suffix() {
    let result = eval_deep_result(
        r#"derivation { name = "foo.drv"; builder = "/bin/sh"; system = "x86_64-linux"; }"#,
@@ -132,7 +131,7 @@ fn derivation_invalid_name_with_drv_suffix() {
    assert!(err_msg.contains("cannot end with .drv"));
 }

-#[test]
+#[test_log::test]
 fn derivation_missing_builder() {
    let result = eval_deep_result(r#"derivation { name = "test"; system = "x86_64-linux"; }"#);

@@ -141,7 +140,7 @@ fn derivation_missing_builder() {
    assert!(err_msg.contains("missing required attribute 'builder'"));
 }

-#[test]
+#[test_log::test]
 fn derivation_missing_system() {
    let result = eval_deep_result(r#"derivation { name = "test"; builder = "/bin/sh"; }"#);

@@ -150,7 +149,7 @@ fn derivation_missing_system() {
    assert!(err_msg.contains("missing required attribute 'system'"));
 }

-#[test]
+#[test_log::test]
 fn derivation_with_env_vars() {
    let result = eval_deep(
        r#"derivation {
@@ -171,7 +170,7 @@ fn derivation_with_env_vars() {
    }
 }

-#[test]
+#[test_log::test]
 fn derivation_strict() {
    let result = eval_deep(
        r#"builtins.derivationStrict { name = "test"; builder = "/bin/sh"; system = "x86_64-linux"; }"#,
@@ -188,7 +187,7 @@ fn derivation_strict() {
    }
 }

-#[test]
+#[test_log::test]
 fn derivation_deterministic_paths() {
    let expr = r#"derivation { name = "hello"; builder = "/bin/sh"; system = "x86_64-linux"; }"#;

@@ -204,7 +203,7 @@ fn derivation_deterministic_paths() {
    }
 }

-#[test]
+#[test_log::test]
 fn derivation_escaping_in_aterm() {
    let result = eval_deep(
        r#"derivation {
@@ -224,7 +223,7 @@ fn derivation_escaping_in_aterm() {
    }
 }

-#[test]
+#[test_log::test]
 fn multi_output_two_outputs() {
    let drv = eval_deep(
        r#"derivation {
@@ -267,7 +266,7 @@ fn multi_output_two_outputs() {
    }
 }

-#[test]
+#[test_log::test]
 fn multi_output_three_outputs() {
    let result = eval_deep(
        r#"derivation {
@@ -315,7 +314,7 @@ fn multi_output_three_outputs() {
    }
 }

-#[test]
+#[test_log::test]
 fn multi_output_backward_compat() {
    let result = eval_deep(
        r#"derivation {
@@ -341,7 +340,7 @@ fn multi_output_backward_compat() {
    }
 }

-#[test]
+#[test_log::test]
 fn multi_output_deterministic() {
    let result1 = eval_deep(
        r#"derivation {
@@ -364,7 +363,7 @@ fn multi_output_deterministic() {
    assert_eq!(result1, result2);
 }

-#[test]
+#[test_log::test]
 fn fixed_output_sha256_flat() {
    let result = eval_deep(
        r#"derivation {
@@ -401,7 +400,7 @@ fn fixed_output_sha256_flat() {
    }
 }

-#[test]
+#[test_log::test]
 fn fixed_output_missing_hashalgo() {
    assert!(
        eval_deep_result(
@@ -416,7 +415,7 @@ fn fixed_output_missing_hashalgo() {
    );
 }

-#[test]
+#[test_log::test]
 fn fixed_output_recursive_mode() {
    let result = eval_deep(
        r#"derivation {
@@ -446,7 +445,7 @@ fn fixed_output_recursive_mode() {
    }
 }

-#[test]
+#[test_log::test]
 fn fixed_output_rejects_multi_output() {
    let result = eval_deep_result(
        r#"derivation {
@@ -464,7 +463,7 @@ fn fixed_output_rejects_multi_output() {
    assert!(err_msg.contains("fixed-output") && err_msg.contains("one"));
 }

-#[test]
+#[test_log::test]
 fn fixed_output_invalid_hash_mode() {
    let result = eval_deep_result(
        r#"derivation {
@@ -481,7 +480,7 @@ fn fixed_output_invalid_hash_mode() {
    assert!(err_msg.contains("outputHashMode") && err_msg.contains("invalid"));
 }

-#[test]
+#[test_log::test]
 fn structured_attrs_basic() {
    let result = eval_deep(
        r#"derivation {
@@ -506,7 +505,7 @@ fn structured_attrs_basic() {
    }
 }

-#[test]
+#[test_log::test]
 fn structured_attrs_nested() {
    let result = eval_deep(
        r#"derivation {
@@ -527,7 +526,7 @@ fn structured_attrs_nested() {
    }
 }

-#[test]
+#[test_log::test]
 fn structured_attrs_rejects_functions() {
    let result = eval_deep_result(
        r#"derivation {
@@ -544,7 +543,7 @@ fn structured_attrs_rejects_functions() {
    assert!(err_msg.contains("cannot convert lambda to JSON"));
 }

-#[test]
+#[test_log::test]
 fn structured_attrs_false() {
    let result = eval_deep(
        r#"derivation {
@@ -567,7 +566,7 @@ fn structured_attrs_false() {
    }
 }

-#[test]
+#[test_log::test]
 fn ignore_nulls_true() {
    let result = eval_deep(
        r#"derivation {
@@ -589,7 +588,7 @@ fn ignore_nulls_true() {
    }
 }

-#[test]
+#[test_log::test]
 fn ignore_nulls_false() {
    let result = eval_deep(
        r#"derivation {
@@ -612,7 +611,7 @@ fn ignore_nulls_false() {
    }
 }

-#[test]
+#[test_log::test]
 fn ignore_nulls_with_structured_attrs() {
    let result = eval_deep(
        r#"derivation {
@@ -636,7 +635,7 @@ fn ignore_nulls_with_structured_attrs() {
    }
 }

-#[test]
+#[test_log::test]
 fn all_features_combined() {
    let result = eval_deep(
        r#"derivation {
@@ -663,7 +662,7 @@ fn all_features_combined() {
    }
 }

-#[test]
+#[test_log::test]
 fn fixed_output_with_structured_attrs() {
    let result = eval_deep(
        r#"derivation {
--- a/nix-js/tests/tests/findfile.rs
+++ b/nix-js/tests/tests/findfile.rs
@@ -1,8 +1,6 @@
-mod utils;
+use crate::utils::eval;

-use utils::eval;
-
-#[test]
+#[test_log::test]
 fn test_find_file_corepkg_fetchurl() {
    let result = eval(
        r#"
@@ -17,13 +15,13 @@ fn test_find_file_corepkg_fetchurl() {
    assert!(result.to_string().contains("fetchurl.nix"));
 }

-#[test]
+#[test_log::test]
 fn test_lookup_path_syntax() {
    let result = eval(r#"<nix/fetchurl.nix>"#);
    assert!(result.to_string().contains("fetchurl.nix"));
 }

-#[test]
+#[test_log::test]
 fn test_import_corepkg() {
    let result = eval(
        r#"
--- a/nix-js/tests/tests/free_globals.rs
+++ b/nix-js/tests/tests/free_globals.rs
@@ -1,24 +1,23 @@
-mod utils;
-
 use nix_js::value::{List, Value};
-use utils::eval;

-#[test]
+use crate::utils::{eval, eval_result};
+
+#[test_log::test]
 fn true_literal() {
    assert_eq!(eval("true"), Value::Bool(true));
 }

-#[test]
+#[test_log::test]
 fn false_literal() {
    assert_eq!(eval("false"), Value::Bool(false));
 }

-#[test]
+#[test_log::test]
 fn null_literal() {
    assert_eq!(eval("null"), Value::Null);
 }

-#[test]
+#[test_log::test]
 fn map_function() {
    assert_eq!(
        eval("map (x: x * 2) [1 2 3]"),
@@ -26,23 +25,23 @@ fn map_function() {
    );
 }

-#[test]
+#[test_log::test]
 fn is_null_function() {
    assert_eq!(eval("isNull null"), Value::Bool(true));
    assert_eq!(eval("isNull 5"), Value::Bool(false));
 }

-#[test]
+#[test_log::test]
 fn shadow_true() {
    assert_eq!(eval("let true = false; in true"), Value::Bool(false));
 }

-#[test]
+#[test_log::test]
 fn shadow_map() {
    assert_eq!(eval("let map = x: y: x; in map 1 2"), Value::Int(1));
 }

-#[test]
+#[test_log::test]
 fn mixed_usage() {
    assert_eq!(
        eval("if true then map (x: x + 1) [1 2] else []"),
@@ -50,7 +49,7 @@ fn mixed_usage() {
    );
 }

-#[test]
+#[test_log::test]
 fn in_let_bindings() {
    assert_eq!(
        eval("let x = true; y = false; in x && y"),
@@ -58,18 +57,18 @@ fn in_let_bindings() {
    );
 }

-#[test]
+#[test_log::test]
 fn shadow_in_function() {
    assert_eq!(eval("(true: true) false"), Value::Bool(false));
 }

-#[test]
+#[test_log::test]
 fn throw_function() {
-    let result = utils::eval_result("throw \"error message\"");
+    let result = eval_result("throw \"error message\"");
    assert!(result.is_err());
 }

-#[test]
+#[test_log::test]
 fn to_string_function() {
    assert_eq!(eval("toString 42"), Value::String("42".to_string()));
 }
--- a/nix-js/tests/tests/functions.rs
+++ b/nix-js/tests/tests/functions.rs
@@ -1,20 +1,19 @@
-mod utils;
-
 use nix_js::value::Value;
-use utils::{eval, eval_result};

-#[test]
+use crate::utils::{eval, eval_result};
+
+#[test_log::test]
 fn required_parameters() {
    assert_eq!(eval("({ a, b }: a + b) { a = 1; b = 2; }"), Value::Int(3));
 }

-#[test]
+#[test_log::test]
 fn missing_required_parameter() {
    let result = eval_result("({ a, b }: a + b) { a = 1; }");
    assert!(result.is_err());
 }

-#[test]
+#[test_log::test]
 fn all_required_parameters_present() {
    assert_eq!(
        eval("({ x, y, z }: x + y + z) { x = 1; y = 2; z = 3; }"),
@@ -22,13 +21,13 @@ fn all_required_parameters_present() {
    );
 }

-#[test]
+#[test_log::test]
 fn reject_unexpected_arguments() {
    let result = eval_result("({ a, b }: a + b) { a = 1; b = 2; c = 3; }");
    assert!(result.is_err());
 }

-#[test]
+#[test_log::test]
 fn ellipsis_accepts_extra_arguments() {
    assert_eq!(
        eval("({ a, b, ... }: a + b) { a = 1; b = 2; c = 3; }"),
@@ -36,12 +35,12 @@ fn ellipsis_accepts_extra_arguments() {
    );
 }

-#[test]
+#[test_log::test]
 fn default_parameters() {
    assert_eq!(eval("({ a, b ? 5 }: a + b) { a = 1; }"), Value::Int(6));
 }

-#[test]
+#[test_log::test]
 fn override_default_parameter() {
    assert_eq!(
        eval("({ a, b ? 5 }: a + b) { a = 1; b = 10; }"),
@@ -49,7 +48,7 @@ fn override_default_parameter() {
    );
 }

-#[test]
+#[test_log::test]
 fn at_pattern_alias() {
    assert_eq!(
        eval("(args@{ a, b }: args.a + args.b) { a = 1; b = 2; }"),
@@ -57,17 +56,17 @@ fn at_pattern_alias() {
    );
 }

-#[test]
+#[test_log::test]
 fn simple_parameter_no_validation() {
    assert_eq!(eval("(x: x.a + x.b) { a = 1; b = 2; }"), Value::Int(3));
 }

-#[test]
+#[test_log::test]
 fn simple_parameter_accepts_any_argument() {
    assert_eq!(eval("(x: x) 42"), Value::Int(42));
 }

-#[test]
+#[test_log::test]
 fn nested_function_parameters() {
    assert_eq!(
        eval("({ a }: { b }: a + b) { a = 5; } { b = 3; }"),
@@ -75,12 +74,12 @@ fn nested_function_parameters() {
    );
 }

-#[test]
+#[test_log::test]
 fn pattern_param_simple_reference_in_default() {
    assert_eq!(eval("({ a, b ? a }: b) { a = 10; }"), Value::Int(10));
 }

-#[test]
+#[test_log::test]
 fn pattern_param_multiple_references_in_default() {
    assert_eq!(
        eval("({ a, b ? a + 5, c ? 1 }: b + c) { a = 10; }"),
@@ -88,7 +87,7 @@ fn pattern_param_multiple_references_in_default() {
    );
 }

-#[test]
+#[test_log::test]
 fn pattern_param_mutual_reference() {
    assert_eq!(
        eval("({ a, b ? c + 1, c ? 5 }: b) { a = 1; }"),
@@ -96,7 +95,7 @@ fn pattern_param_mutual_reference() {
    );
 }

-#[test]
+#[test_log::test]
 fn pattern_param_override_mutual_reference() {
    assert_eq!(
        eval("({ a, b ? c + 1, c ? 5 }: b) { a = 1; c = 10; }"),
@@ -104,7 +103,7 @@ fn pattern_param_override_mutual_reference() {
    );
 }

-#[test]
+#[test_log::test]
 fn pattern_param_reference_list() {
    assert_eq!(
        eval("({ a, b ? [ a 2 ] }: builtins.elemAt b 0) { a = 42; }"),
@@ -112,7 +111,7 @@ fn pattern_param_reference_list() {
    );
 }

-#[test]
+#[test_log::test]
 fn pattern_param_alias_in_default() {
    assert_eq!(
        eval("(args@{ a, b ? args.a + 10 }: b) { a = 5; }"),
--- a/nix-js/tests/tests/io_operations.rs
+++ b/nix-js/tests/tests/io_operations.rs
@@ -1,12 +1,10 @@
-mod utils;
-
 use nix_js::context::Context;
 use nix_js::error::Source;
 use nix_js::value::Value;

 use crate::utils::{eval, eval_result};

-#[test]
+#[test_log::test]
 fn import_absolute_path() {
    let temp_dir = tempfile::tempdir().unwrap();
    let lib_path = temp_dir.path().join("nix_test_lib.nix");
@@ -17,7 +15,7 @@ fn import_absolute_path() {
    assert_eq!(eval(&expr), Value::Int(8));
 }

-#[test]
+#[test_log::test]
 fn import_nested() {
    let temp_dir = tempfile::tempdir().unwrap();

@@ -35,7 +33,7 @@ fn import_nested() {
    assert_eq!(eval(&expr), Value::Int(30));
 }

-#[test]
+#[test_log::test]
 fn import_relative_path() {
    let temp_dir = tempfile::tempdir().unwrap();
    let subdir = temp_dir.path().join("subdir");
@@ -66,7 +64,7 @@ fn import_relative_path() {
    assert_eq!(eval(&expr), Value::Int(7));
 }

-#[test]
+#[test_log::test]
 fn import_returns_function() {
    let temp_dir = tempfile::tempdir().unwrap();
    let func_path = temp_dir.path().join("nix_test_func.nix");
@@ -76,7 +74,7 @@ fn import_returns_function() {
    assert_eq!(eval(&expr), Value::Int(10));
 }

-#[test]
+#[test_log::test]
 fn import_with_complex_dependency_graph() {
    let temp_dir = tempfile::tempdir().unwrap();

@@ -97,7 +95,7 @@ fn import_with_complex_dependency_graph() {

 // Tests for builtins.path

-#[test]
+#[test_log::test]
 fn path_with_file() {
    let mut ctx = Context::new().unwrap();
    let temp_dir = tempfile::tempdir().unwrap();
@@ -116,7 +114,7 @@ fn path_with_file() {
    }
 }

-#[test]
+#[test_log::test]
 fn path_with_custom_name() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_file = temp_dir.path().join("original.txt");
@@ -136,7 +134,7 @@ fn path_with_custom_name() {
    }
 }

-#[test]
+#[test_log::test]
 fn path_with_directory_recursive() {
    let mut ctx = Context::new().unwrap();
    let temp_dir = tempfile::tempdir().unwrap();
@@ -159,7 +157,7 @@ fn path_with_directory_recursive() {
    }
 }

-#[test]
+#[test_log::test]
 fn path_flat_with_file() {
    let mut ctx = Context::new().unwrap();
    let temp_dir = tempfile::tempdir().unwrap();
@@ -179,7 +177,7 @@ fn path_flat_with_file() {
    }
 }

-#[test]
+#[test_log::test]
 fn path_flat_with_directory_fails() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_dir = temp_dir.path().join("mydir");
@@ -196,7 +194,7 @@ fn path_flat_with_directory_fails() {
    assert!(err_msg.contains("recursive") || err_msg.contains("regular file"));
 }

-#[test]
+#[test_log::test]
 fn path_nonexistent_fails() {
    let expr = r#"builtins.path { path = "/nonexistent/path/that/should/not/exist"; }"#;
    let result = eval_result(expr);
@@ -206,7 +204,7 @@ fn path_nonexistent_fails() {
    assert!(err_msg.contains("does not exist"));
 }

-#[test]
+#[test_log::test]
 fn path_missing_path_param() {
    let expr = r#"builtins.path { name = "test"; }"#;
    let result = eval_result(expr);
@@ -216,7 +214,7 @@ fn path_missing_path_param() {
    assert!(err_msg.contains("path") && err_msg.contains("required"));
 }

-#[test]
+#[test_log::test]
 fn path_with_sha256() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_file = temp_dir.path().join("hash_test.txt");
@@ -243,7 +241,7 @@ fn path_with_sha256() {
    assert_eq!(store_path1, store_path2);
 }

-#[test]
+#[test_log::test]
 fn path_deterministic() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_file = temp_dir.path().join("deterministic.txt");
@@ -261,7 +259,7 @@ fn path_deterministic() {
    assert_eq!(result1, result2);
 }

-#[test]
+#[test_log::test]
 fn read_file_type_regular_file() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_file = temp_dir.path().join("test.txt");
@@ -271,7 +269,7 @@ fn read_file_type_regular_file() {
    assert_eq!(eval(&expr), Value::String("regular".to_string()));
 }

-#[test]
+#[test_log::test]
 fn read_file_type_directory() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_dir = temp_dir.path().join("testdir");
@@ -281,7 +279,7 @@ fn read_file_type_directory() {
    assert_eq!(eval(&expr), Value::String("directory".to_string()));
 }

-#[test]
+#[test_log::test]
 fn read_file_type_symlink() {
    let temp_dir = tempfile::tempdir().unwrap();
    let target = temp_dir.path().join("target.txt");
@@ -299,7 +297,7 @@ fn read_file_type_symlink() {
    }
 }

-#[test]
+#[test_log::test]
 fn read_dir_basic() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_dir = temp_dir.path().join("readdir_test");
@@ -331,7 +329,7 @@ fn read_dir_basic() {
    }
 }

-#[test]
+#[test_log::test]
 fn read_dir_empty() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_dir = temp_dir.path().join("empty_dir");
@@ -347,7 +345,7 @@ fn read_dir_empty() {
    }
 }

-#[test]
+#[test_log::test]
 fn read_dir_nonexistent_fails() {
    let expr = r#"builtins.readDir "/nonexistent/directory""#;
    let result = eval_result(expr);
@@ -355,7 +353,7 @@ fn read_dir_nonexistent_fails() {
    assert!(result.is_err());
 }

-#[test]
+#[test_log::test]
 fn read_dir_on_file_fails() {
    let temp_dir = tempfile::tempdir().unwrap();
    let test_file = temp_dir.path().join("test.txt");
--- a/nix-js/tests/tests/lang.rs
+++ b/nix-js/tests/tests/lang.rs
@@ -1,7 +1,5 @@
 #![allow(non_snake_case)]

-mod utils;
-
 use std::path::PathBuf;

 use nix_js::context::Context;
@@ -9,7 +7,7 @@ use nix_js::error::Source;
 use nix_js::value::Value;

 fn get_lang_dir() -> PathBuf {
-    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("tests/lang")
+    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("tests/tests/lang")
 }

 fn eval_file(name: &str) -> Result<(Value, Source), String> {
@@ -44,7 +42,7 @@ fn format_value(value: &Value) -> String {
 macro_rules! eval_okay_test {
    ($(#[$attr:meta])* $name:ident$(, $pre:expr)?) => {
        $(#[$attr])*
-        #[test]
+        #[test_log::test]
        fn $name() {
            $(($pre)();)?
            let test_name = concat!("eval-okay-", stringify!($name))
@@ -76,7 +74,7 @@ macro_rules! eval_okay_test {

 macro_rules! eval_fail_test {
    ($name:ident) => {
-        #[test]
+        #[test_log::test]
        fn $name() {
            let test_name = concat!("eval-fail-", stringify!($name))
                .replace("_", "-")
@@ -122,10 +120,7 @@ eval_okay_test!(concatmap);
 eval_okay_test!(concatstringssep);
 eval_okay_test!(context);
 eval_okay_test!(context_introspection);
-eval_okay_test!(
-    #[ignore = "not implemented: convertHash"]
-    convertHash
-);
+eval_okay_test!(convertHash);
 eval_okay_test!(curpos);
 eval_okay_test!(deepseq);
 eval_okay_test!(delayed_with);
@@ -158,24 +153,15 @@ eval_okay_test!(
    fromTOML_timestamps
 );
 eval_okay_test!(functionargs);
-eval_okay_test!(
-    #[ignore = "not implemented: hashFile"]
-    hashfile
-);
-eval_okay_test!(
-    #[ignore = "not implemented: hashString"]
-    hashstring
-);
+eval_okay_test!(hashfile);
+eval_okay_test!(hashstring);
 eval_okay_test!(getattrpos);
 eval_okay_test!(getattrpos_functionargs);
 eval_okay_test!(getattrpos_undefined);
 eval_okay_test!(getenv, || {
    unsafe { std::env::set_var("TEST_VAR", "foo") };
 });
-eval_okay_test!(
-    #[ignore = "not implemented: hashString"]
-    groupBy
-);
+eval_okay_test!(groupBy);
 eval_okay_test!(r#if);
 eval_okay_test!(ind_string);
 eval_okay_test!(import);
@@ -206,15 +192,11 @@ eval_okay_test!(
 eval_okay_test!(partition);
 eval_okay_test!(path);
 eval_okay_test!(pathexists);
-eval_okay_test!(
-    #[ignore = "rnix 0.13 regression: /${foo}-/*...*/ fails to parse"]
-    path_string_interpolation,
-    || {
+eval_okay_test!(path_string_interpolation, || {
    unsafe {
        std::env::set_var("HOME", "/fake-home");
    }
-    }
-);
+});
 eval_okay_test!(patterns);
 eval_okay_test!(print);
 eval_okay_test!(readDir);
@@ -253,22 +235,13 @@ eval_okay_test!(
    tail_call_1
 );
 eval_okay_test!(tojson);
-eval_okay_test!(
-    #[ignore = "not implemented: toXML"]
-    toxml
-);
-eval_okay_test!(
-    #[ignore = "not implemented: toXML"]
-    toxml2
-);
+eval_okay_test!(toxml);
+eval_okay_test!(toxml2);
 eval_okay_test!(tryeval);
 eval_okay_test!(types);
 eval_okay_test!(versions);
 eval_okay_test!(with);
-eval_okay_test!(
-    #[ignore = "not implemented: hashString"]
-    zipAttrsWith
-);
+eval_okay_test!(zipAttrsWith);

 eval_fail_test!(fail_abort);
 eval_fail_test!(fail_addDrvOutputDependencies_empty_context);
--- a/nix-js/tests/tests/lang/binary-data
+++ b/nix-js/tests/tests/lang/binary-data
--- a/nix-js/tests/tests/lang/data
+++ b/nix-js/tests/tests/lang/data
--- a/nix-js/tests/tests/lang/dir1/a.nix
+++ b/nix-js/tests/tests/lang/dir1/a.nix
--- a/nix-js/tests/tests/lang/dir2/a.nix
+++ b/nix-js/tests/tests/lang/dir2/a.nix
--- a/nix-js/tests/tests/lang/dir2/b.nix
+++ b/nix-js/tests/tests/lang/dir2/b.nix
--- a/nix-js/tests/tests/lang/dir3/a.nix
+++ b/nix-js/tests/tests/lang/dir3/a.nix
--- a/nix-js/tests/tests/lang/dir3/b.nix
+++ b/nix-js/tests/tests/lang/dir3/b.nix
--- a/nix-js/tests/tests/lang/dir3/c.nix
+++ b/nix-js/tests/tests/lang/dir3/c.nix
--- a/nix-js/tests/tests/lang/dir4/a.nix
+++ b/nix-js/tests/tests/lang/dir4/a.nix
--- a/nix-js/tests/tests/lang/dir4/c.nix
+++ b/nix-js/tests/tests/lang/dir4/c.nix
--- a/nix-js/tests/tests/lang/eval-fail-abort.err.exp
+++ b/nix-js/tests/tests/lang/eval-fail-abort.err.exp
--- a/nix-js/tests/tests/lang/eval-fail-abort.nix
+++ b/nix-js/tests/tests/lang/eval-fail-abort.nix
--- a/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-empty-context.err.exp
+++ b/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-empty-context.err.exp
--- a/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-empty-context.nix
+++ b/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-empty-context.nix
--- a/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-multi-elem-context.err.exp
+++ b/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-multi-elem-context.err.exp
--- a/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-multi-elem-context.nix
+++ b/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-multi-elem-context.nix
--- a/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-wrong-element-kind.err.exp
+++ b/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-wrong-element-kind.err.exp
--- a/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-wrong-element-kind.nix
+++ b/nix-js/tests/tests/lang/eval-fail-addDrvOutputDependencies-wrong-element-kind.nix
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
imxyy_soope_	7a7229d70e	fmt: group_imports = "StdExternalCrate"	2026-03-08 17:41:06 +08:00
imxyy_soope_	e4004ccb6d	feat: bytecode	2026-03-08 17:41:06 +08:00
imxyy_soope_	843ae6cfb4	refactor: use GhostCell to provide interior mutability in Ir	2026-03-08 16:57:34 +08:00
imxyy_soope_	c24d6a8bb3	chore: merge `codegen::compile` and `codegen::compile_scoped`	2026-02-25 21:14:35 +08:00
imxyy_soope_	d7351e907b	feat: thunk caching (WIP)	2026-02-25 21:14:27 +08:00
imxyy_soope_	550223a1d7	refactor: tidy	2026-02-21 22:30:13 +08:00
imxyy_soope_	53dbee3514	refactor(downgrade): use bumpalo	2026-02-21 21:54:40 +08:00
imxyy_soope_	e1517c338e	chore: tidy	2026-02-20 16:12:54 +08:00
imxyy_soope_	45096f5254	fix: fetchGit	2026-02-19 22:34:41 +08:00
imxyy_soope_	b57fea3104	optimize: short-circuit update (//)	2026-02-19 21:54:55 +08:00
imxyy_soope_	4380fa85c4	optimize: compact	2026-02-19 21:14:02 +08:00
imxyy_soope_	99045aa76c	chore: fmt	2026-02-19 20:14:06 +08:00
imxyy_soope_	7eb3acf26f	optimize: use v8::Script::compile to run script directly in op_import	2026-02-19 19:58:02 +08:00
imxyy_soope_	b424f60f9f	optimize: avoid using #[serde] in ops	2026-02-19 19:11:56 +08:00
imxyy_soope_	42031edac1	optimize: generate shorter code	2026-02-19 17:16:35 +08:00
imxyy_soope_	04dcadfd61	optimize	2026-02-18 20:45:50 +08:00
imxyy_soope_	c3c39bda0c	feat: v8 profiling	2026-02-18 20:45:50 +08:00
imxyy_soope_	782092b91e	optimize: type check	2026-02-18 20:45:50 +08:00
imxyy_soope_	ae5febd5dd	feat(cli): compile	2026-02-18 20:45:42 +08:00
imxyy_soope_	3cc7c7be75	chore: update deps; restructure tests; use Map over Record	2026-02-17 12:02:54 +08:00
imxyy_soope_	f49634ccc0	optimize: use Map to represent NixAttrs	2026-02-17 10:35:37 +08:00
imxyy_soope_	4a885c18b8	chore: add eslint	2026-02-17 10:35:37 +08:00
imxyy_soope_	37e395c0e3	optimize: builtins.intersectAttrs	2026-02-16 23:07:52 +08:00
imxyy_soope_	16a8480d29	feat(cli): support eval file	2026-02-16 21:52:08 +08:00
imxyy_soope_	f0a0593d4c	feat: implement builtins.toXML	2026-02-16 19:52:33 +08:00
imxyy_soope_	ce64a82da3	feat: inspector	2026-02-16 19:52:33 +08:00
imxyy_soope_	5c48e5cfdd	feat: implement hash related primops	2026-02-15 19:55:29 +08:00
imxyy_soope_	7836f8c869	refactor: handle derivation generation on Rust side	2026-02-15 19:38:11 +08:00
imxyy_soope_	e357678d70	feat: implement realisePath	2026-02-15 18:26:24 +08:00
imxyy_soope_	2f2c690023	chore(runtime-ts): fix linter errors	2026-02-15 12:20:31 +08:00
				`@@ -1 +0,0 @@`
				`[ { } { a = 1; } { a = 1; } { a = "a"; } { m = 1; } { m = "m"; } { n = 1; } { n = "n"; } { n = 1; p = 2; } { n = "n"; p = "p"; } { n = 1; p = 2; } { n = "n"; p = "p"; } { a = "a"; b = "b"; c = "c"; d = "d"; e = "e"; f = "f"; g = "g"; h = "h"; i = "i"; j = "j"; k = "k"; l = "l"; m = "m"; n = "n"; o = "o"; p = "p"; q = "q"; r = "r"; s = "s"; t = "t"; u = "u"; v = "v"; w = "w"; x = "x"; y = "y"; z = "z"; } true ]`
				`@@ -1 +0,0 @@`
				`[ null <PRIMOP> <PRIMOP-APP> <LAMBDA> [ [ «repeated» ] ] ]`