diff --git a/.github/workflows/js-sdk.yaml b/.github/workflows/js-sdk.yaml
new file mode 100644
index 000000000..be17c9a30
--- /dev/null
+++ b/.github/workflows/js-sdk.yaml
@@ -0,0 +1,33 @@
+name: JavaScript SDK
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: namespace-profile-standard-ubuntu22-amd64
+    steps:
+      - name: clone code
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+      - name: install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly-2023-11-16
+          override: true
+      - uses: oven-sh/setup-bun@v1
+        with:
+          bun-version: latest
+      - name: install deps
+        working-directory: ./js/node-api
+        run: bun install
+      - name: build Node API
+        working-directory: ./js/node-api
+        run: bun run build
+      - name: test Node API
+        working-directory: ./js/node-api
+        run: bun test
diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index de79f9354..aff03d5d7 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -12,7 +12,7 @@ on:
 
 jobs:
   test:
-    runs-on: "nscloud-ubuntu-22.04-amd64-4x16"
+    runs-on: namespace-profile-standard-ubuntu22-amd64
     strategy:
       matrix:
         python-version: ["3.10"]
diff --git a/Cargo.lock b/Cargo.lock
index c52c8c5a4..a1a56dfe2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1433,6 +1433,19 @@ dependencies = [
  "regex-syntax 0.8.2",
 ]
 
+[[package]]
+name = "grit-node-api"
+version = "0.0.0"
+dependencies = [
+ "anyhow",
+ "marzano-core",
+ "marzano-util",
+ "napi",
+ "napi-build",
+ "napi-derive",
+ "serde_json",
+]
+
 [[package]]
 name = "grit-pattern-matcher"
 version = "0.3.0"
@@ -2595,6 +2608,12 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "napi-build"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1c0f5d67ee408a4685b61f5ab7e58605c8ae3f2b4189f0127d804ff13d5560a"
+
 [[package]]
 name = "napi-derive"
 version = "2.16.3"
diff --git a/Cargo.toml b/Cargo.toml
index 8810ff029..6e3fb731d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,7 @@ members = [
   "crates/wasm-bindings",
   "crates/marzano_messenger",
   "crates/cli_bin",
+  "js/node-api",
 ]
 exclude = [
   "resources",
diff --git a/js/.gitignore b/js/.gitignore
new file mode 100644
index 000000000..1f68e8c58
--- /dev/null
+++ b/js/.gitignore
@@ -0,0 +1,182 @@
+### Node ###
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+.env.test
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+
+# Next.js build output
+.next
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+### macOS ###
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two
+Icon
+
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### macOS Patch ###
+# iCloud generated files
+*.icloud
+
+### Windows ###
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+#Added by cargo
+
+/target
+Cargo.lock
+
+.pnp.*
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/releases
+!.yarn/sdks
+!.yarn/versions
+
+*.node
diff --git a/js/node-api/Cargo.toml b/js/node-api/Cargo.toml
new file mode 100644
index 000000000..7bdc67ad8
--- /dev/null
+++ b/js/node-api/Cargo.toml
@@ -0,0 +1,28 @@
+[package]
+edition = "2021"
+name = "grit-node-api"
+version = "0.0.0"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+# Default enable napi4 feature, see https://nodejs.org/api/n-api.html#node-api-version-matrix
+napi = { version = "2.16.4", default-features = false, features = [
+  "napi8",
+  "async",
+] }
+napi-derive = "2.12.2"
+anyhow = "1.0.70"
+serde_json = "1.0.113"
+
+marzano-util = { path = "../../crates/util", features = ["napi"] }
+marzano-core = { path = "../../crates/core", features = [
+  "network_requests",
+  "non_wasm",
+  "napi",
+  "language-parsers",
+], default-features = false }
+
+[build-dependencies]
+napi-build = "2.0.1"
diff --git a/js/node-api/__generated__/index.d.ts b/js/node-api/__generated__/index.d.ts
new file mode 100644
index 000000000..23c4fe1ad
--- /dev/null
+++ b/js/node-api/__generated__/index.d.ts
@@ -0,0 +1,68 @@
+/* tslint:disable */
+/* eslint-disable */
+
+/* auto-generated by NAPI-RS */
+
+export interface Position {
+  /** 1-based line number in the source file. */
+  line: number
+  /** 1-based column number in the source file. */
+  column: number
+}
+export interface RangeWithoutByte {
+  start: Position
+  end: Position
+}
+export interface RangePair {
+  before: RangeWithoutByte
+  after: RangeWithoutByte
+}
+export interface FileDiff {
+  oldPath?: string
+  newPath?: string
+  ranges: Array<RangePair>
+}
+export interface RichFile {
+  path: string
+  content: string
+}
+export function sum(a: number, b: number): number
+/** We need this to make sure the builder is actually exposed to JS */
+export function debugBuilder(builder: UncompiledPatternBuilder): string
+export class UncompiledPatternBuilder {
+  static new_snippet(text: string): UncompiledPatternBuilder
+  /** Filter this pattern to only match instances that contain the other pattern */
+  contains(other: UncompiledPatternBuilder): UncompiledPatternBuilder
+  /** Filter the pattern to only match instances that match a provided callback */
+  filter(callback: (arg: ResultBinding) => any): UncompiledPatternBuilder
+  /** Run the pattern on a list of files and return the number of matching files found */
+  runOnFiles(files: Array<RichFile>): Promise<number>
+  /**
+   * Apply the query to a single file and return the modified file (if any)
+   * @param file The file to apply the query to
+   * @returns The modified file (if it was modified)
+   */
+  runOnFile(file: RichFile): Promise<RichFile | null>
+}
+/**
+ * Resolved bindings provide hooks for JavaScript code to interact with a bit of code that has been matched by a pattern.
+ * The binding corresponds to a specific piece of text, which can be further filtered against or modified inside a JavaScript callback.
+ */
+export class ResultBinding {
+  /** Retrieves the stringified representation of the binding (ie. the actual source code) */
+  text(): string
+  /** If the binding was found in a source file, return the position of the binding. */
+  range(): RangeWithoutByte | null
+  /** Retrieves the absolute file name of the file containing the current binding. */
+  filename(): string
+  /**
+   * Inserts the provided text after the binding.
+   * The GritQL engine handles the insertion of the text in transformed output code.
+   */
+  append(text: string): void
+  /**
+   * Retrieve a variable's text from the current scope.
+   * @hidden This API is not stable yet.
+   */
+  findVarText(name: string): string | null
+}
diff --git a/js/node-api/__generated__/index.js b/js/node-api/__generated__/index.js
new file mode 100644
index 000000000..229b9e72b
--- /dev/null
+++ b/js/node-api/__generated__/index.js
@@ -0,0 +1,318 @@
+/* tslint:disable */
+/* eslint-disable */
+/* prettier-ignore */
+
+/* auto-generated by NAPI-RS */
+
+const { existsSync, readFileSync } = require('fs')
+const { join } = require('path')
+
+const { platform, arch } = process
+
+let nativeBinding = null
+let localFileExisted = false
+let loadError = null
+
+function isMusl() {
+  // For Node 10
+  if (!process.report || typeof process.report.getReport !== 'function') {
+    try {
+      const lddPath = require('child_process').execSync('which ldd').toString().trim()
+      return readFileSync(lddPath, 'utf8').includes('musl')
+    } catch (e) {
+      return true
+    }
+  } else {
+    const { glibcVersionRuntime } = process.report.getReport().header
+    return !glibcVersionRuntime
+  }
+}
+
+switch (platform) {
+  case 'android':
+    switch (arch) {
+      case 'arm64':
+        localFileExisted = existsSync(join(__dirname, 'grit-node-api.android-arm64.node'))
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.android-arm64.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-android-arm64')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      case 'arm':
+        localFileExisted = existsSync(join(__dirname, 'grit-node-api.android-arm-eabi.node'))
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.android-arm-eabi.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-android-arm-eabi')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      default:
+        throw new Error(`Unsupported architecture on Android ${arch}`)
+    }
+    break
+  case 'win32':
+    switch (arch) {
+      case 'x64':
+        localFileExisted = existsSync(
+          join(__dirname, 'grit-node-api.win32-x64-msvc.node')
+        )
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.win32-x64-msvc.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-win32-x64-msvc')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      case 'ia32':
+        localFileExisted = existsSync(
+          join(__dirname, 'grit-node-api.win32-ia32-msvc.node')
+        )
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.win32-ia32-msvc.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-win32-ia32-msvc')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      case 'arm64':
+        localFileExisted = existsSync(
+          join(__dirname, 'grit-node-api.win32-arm64-msvc.node')
+        )
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.win32-arm64-msvc.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-win32-arm64-msvc')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      default:
+        throw new Error(`Unsupported architecture on Windows: ${arch}`)
+    }
+    break
+  case 'darwin':
+    localFileExisted = existsSync(join(__dirname, 'grit-node-api.darwin-universal.node'))
+    try {
+      if (localFileExisted) {
+        nativeBinding = require('./grit-node-api.darwin-universal.node')
+      } else {
+        nativeBinding = require('@getgrit/node-api-darwin-universal')
+      }
+      break
+    } catch {}
+    switch (arch) {
+      case 'x64':
+        localFileExisted = existsSync(join(__dirname, 'grit-node-api.darwin-x64.node'))
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.darwin-x64.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-darwin-x64')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      case 'arm64':
+        localFileExisted = existsSync(
+          join(__dirname, 'grit-node-api.darwin-arm64.node')
+        )
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.darwin-arm64.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-darwin-arm64')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      default:
+        throw new Error(`Unsupported architecture on macOS: ${arch}`)
+    }
+    break
+  case 'freebsd':
+    if (arch !== 'x64') {
+      throw new Error(`Unsupported architecture on FreeBSD: ${arch}`)
+    }
+    localFileExisted = existsSync(join(__dirname, 'grit-node-api.freebsd-x64.node'))
+    try {
+      if (localFileExisted) {
+        nativeBinding = require('./grit-node-api.freebsd-x64.node')
+      } else {
+        nativeBinding = require('@getgrit/node-api-freebsd-x64')
+      }
+    } catch (e) {
+      loadError = e
+    }
+    break
+  case 'linux':
+    switch (arch) {
+      case 'x64':
+        if (isMusl()) {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-x64-musl.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-x64-musl.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-x64-musl')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        } else {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-x64-gnu.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-x64-gnu.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-x64-gnu')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        }
+        break
+      case 'arm64':
+        if (isMusl()) {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-arm64-musl.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-arm64-musl.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-arm64-musl')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        } else {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-arm64-gnu.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-arm64-gnu.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-arm64-gnu')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        }
+        break
+      case 'arm':
+        if (isMusl()) {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-arm-musleabihf.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-arm-musleabihf.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-arm-musleabihf')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        } else {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-arm-gnueabihf.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-arm-gnueabihf.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-arm-gnueabihf')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        }
+        break
+      case 'riscv64':
+        if (isMusl()) {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-riscv64-musl.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-riscv64-musl.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-riscv64-musl')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        } else {
+          localFileExisted = existsSync(
+            join(__dirname, 'grit-node-api.linux-riscv64-gnu.node')
+          )
+          try {
+            if (localFileExisted) {
+              nativeBinding = require('./grit-node-api.linux-riscv64-gnu.node')
+            } else {
+              nativeBinding = require('@getgrit/node-api-linux-riscv64-gnu')
+            }
+          } catch (e) {
+            loadError = e
+          }
+        }
+        break
+      case 's390x':
+        localFileExisted = existsSync(
+          join(__dirname, 'grit-node-api.linux-s390x-gnu.node')
+        )
+        try {
+          if (localFileExisted) {
+            nativeBinding = require('./grit-node-api.linux-s390x-gnu.node')
+          } else {
+            nativeBinding = require('@getgrit/node-api-linux-s390x-gnu')
+          }
+        } catch (e) {
+          loadError = e
+        }
+        break
+      default:
+        throw new Error(`Unsupported architecture on Linux: ${arch}`)
+    }
+    break
+  default:
+    throw new Error(`Unsupported OS: ${platform}, architecture: ${arch}`)
+}
+
+if (!nativeBinding) {
+  if (loadError) {
+    throw loadError
+  }
+  throw new Error(`Failed to load native binding`)
+}
+
+const { UncompiledPatternBuilder, ResultBinding, sum, debugBuilder } = nativeBinding
+
+module.exports.UncompiledPatternBuilder = UncompiledPatternBuilder
+module.exports.ResultBinding = ResultBinding
+module.exports.sum = sum
+module.exports.debugBuilder = debugBuilder
diff --git a/js/node-api/build.rs b/js/node-api/build.rs
new file mode 100644
index 000000000..9fc236788
--- /dev/null
+++ b/js/node-api/build.rs
@@ -0,0 +1,5 @@
+extern crate napi_build;
+
+fn main() {
+    napi_build::setup();
+}
diff --git a/js/node-api/package.json b/js/node-api/package.json
new file mode 100644
index 000000000..f2d35bb2e
--- /dev/null
+++ b/js/node-api/package.json
@@ -0,0 +1,22 @@
+{
+  "name": "@getgrit/node-api",
+  "version": "0.0.0",
+  "main": "__generated__/index.js",
+  "types": "__generated__/index.d.ts",
+  "napi": {
+    "name": "grit-node-api",
+    "triples": {}
+  },
+  "license": "UNLICENSED",
+  "devDependencies": {
+    "@napi-rs/cli": "^2.18.3"
+  },
+  "engines": {
+    "node": ">= 10"
+  },
+  "scripts": {
+    "build": "if [ -z \"$SKIP_BRIDGE\" ]; then RUSTFLAGS=\"-A warnings\" napi build --no-const-enum --platform --release --dts __generated__/index.d.ts --js __generated__/index.js && mv *.node __generated__; fi",
+    "test": "bun test",
+    "test:ci": "bun test --run"
+  }
+}
diff --git a/js/node-api/src/lib.rs b/js/node-api/src/lib.rs
new file mode 100644
index 000000000..3b26bd651
--- /dev/null
+++ b/js/node-api/src/lib.rs
@@ -0,0 +1,23 @@
+#[macro_use]
+extern crate napi_derive;
+
+use napi::bindgen_prelude::*;
+use std::path::{Path, PathBuf};
+use std::str::FromStr;
+
+use anyhow::Context;
+
+// Exported API
+pub use marzano_core::UncompiledPatternBuilder;
+
+#[napi]
+pub fn sum(a: i32, b: i32) -> Result<i32> {
+    Ok(a + b)
+}
+
+/// We need this to make sure the builder is actually exposed to JS
+#[napi]
+pub fn debug_builder(builder: &UncompiledPatternBuilder) -> Result<String> {
+    let builder_str = format!("{:?}", builder);
+    Ok(builder_str)
+}
diff --git a/js/node-api/test/builder.spec.mts b/js/node-api/test/builder.spec.mts
new file mode 100644
index 000000000..d28c43fd2
--- /dev/null
+++ b/js/node-api/test/builder.spec.mts
@@ -0,0 +1,163 @@
+import { expect, describe, it } from 'bun:test';
+
+import { UncompiledPatternBuilder } from '../__generated__/index.js';
+
+describe('Grit builder bindings', () => {
+  it('can save text from the repo', async () => {
+    const query = UncompiledPatternBuilder.new_snippet('console.log');
+    const result = await query.runOnFiles([
+      { path: 'test/file1.js', content: 'console.log("hello")' },
+      { path: 'test/file2.js', content: 'throw new Error("oh no")' },
+    ]);
+    console.log('result', result);
+    expect(result).toBe(1);
+    const result2 = await query.runOnFiles([
+      { path: 'test/file1.js', content: 'console.error("hello")' },
+      { path: 'test/file2.js', content: 'throw new Error("oh no")' },
+    ]);
+    expect(result2).toBe(0);
+  });
+
+  it('can use nested contains', async () => {
+    const query = UncompiledPatternBuilder.new_snippet('console.log').contains(
+      UncompiledPatternBuilder.new_snippet('log'),
+    );
+    const result = await query.runOnFiles([
+      { path: 'test', content: 'console.log("hello")' },
+      { path: 'not_a_file', content: 'throw new Error("oh no")' },
+    ]);
+    expect(result).toBe(1);
+    // This one shoud not match, because there is not a fun inside;
+    const result2 = await UncompiledPatternBuilder.new_snippet('console.log($_)')
+      .contains(UncompiledPatternBuilder.new_snippet('fun'))
+      .runOnFiles([
+        { path: 'test', content: 'console.log(food); fun' },
+        { path: 'not_a_file', content: 'throw new Error("oh no")' },
+      ]);
+    expect(result2).toBe(0);
+  });
+
+  it('can use a callback', async () => {
+    let callbackCalledCounter = {
+      value: 0,
+    };
+    const query = UncompiledPatternBuilder.new_snippet('console.log').filter((data) => {
+      console.log('The callback was called');
+      callbackCalledCounter.value++;
+      return true;
+    });
+    const result = await query.runOnFiles([
+      {
+        path: 'test',
+        content: 'function foo() { console.log("hello"); console.log("world"); } foo();',
+      },
+      { path: 'not_a_file', content: 'throw new Error("oh no")' },
+    ]);
+    expect(result).toBe(1);
+    expect(callbackCalledCounter.value).toBe(2);
+  });
+
+  it('can apply a rewrite with a pattern', async () => {
+    const query = UncompiledPatternBuilder.new_snippet('import $_').filter((arg: any) => {
+      arg.append(`<<<INSERT HERE>>>\n`);
+      return true;
+    });
+
+    const modified = await query.runOnFile({
+      path: 'test.js',
+      content: `import { foo } from 'bar';
+import { baz } from 'qux';
+import { quux } from 'corge';
+
+function foo() {
+  console.log('foo');
+}`,
+    });
+    expect(modified).toBeDefined();
+    expect(modified!.content).toBe(`import { foo } from 'bar';
+<<<INSERT HERE>>>
+
+import { baz } from 'qux';
+<<<INSERT HERE>>>
+
+import { quux } from 'corge';
+<<<INSERT HERE>>>
+
+
+function foo() {
+  console.log('foo');
+}`);
+  });
+
+  it('can filter content correctly in callbacks', async () => {
+    const query = UncompiledPatternBuilder.new_snippet('import $_')
+      .filter((arg: any) => {
+        const text = arg.text();
+        if (text.includes('baz')) {
+          return true;
+        }
+        return false;
+      })
+      .filter((arg: any) => {
+        arg.append(`<<<INSERT HERE>>>\n`);
+        return true;
+      });
+
+    const modified = await query.runOnFile({
+      path: 'test.js',
+      content: `import { foo } from 'bar';
+import { baz } from 'qux';
+import { quux } from 'corge';
+
+function foo() {
+  console.log('foo');
+}`,
+    });
+    expect(modified).toBeDefined();
+    expect(modified!.content).toBe(`import { foo } from 'bar';
+import { baz } from 'qux';
+<<<INSERT HERE>>>
+
+import { quux } from 'corge';
+
+function foo() {
+  console.log('foo');
+}`);
+  });
+
+  it('can find variables inside the context ', async () => {
+    const query = UncompiledPatternBuilder.new_snippet('import { $items } from "$source"')
+      .filter((arg: any) => {
+        const source = arg.findVarText('$source');
+        if (source === 'qux') {
+          return true;
+        }
+        return false;
+      })
+      .filter((arg: any) => {
+        arg.append(`<<<INSERT HERE>>>\n`);
+        return true;
+      });
+
+    const modified = await query.runOnFile({
+      path: 'test.js',
+      content: `import { foo } from 'bar';
+import { baz } from 'qux';
+import { quux } from 'corge';
+
+function foo() {
+  console.log('foo');
+}`,
+    });
+    expect(modified).toBeDefined();
+    expect(modified!.content).toBe(`import { foo } from 'bar';
+import { baz } from 'qux';
+<<<INSERT HERE>>>
+
+import { quux } from 'corge';
+
+function foo() {
+  console.log('foo');
+}`);
+  });
+});
diff --git a/js/node-api/test/sum.spec.mts b/js/node-api/test/sum.spec.mts
new file mode 100644
index 000000000..539cf7118
--- /dev/null
+++ b/js/node-api/test/sum.spec.mts
@@ -0,0 +1,10 @@
+import { expect, describe, it } from 'bun:test';
+
+import { sum } from '../__generated__/index.js';
+
+describe('Node bindings', () => {
+  it('work with a basic function', async () => {
+    const result = sum(1, 2);
+    expect(result).toBe(3);
+  });
+});