cc2js

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This CLI tool can convert Bun-compiled binaries of any Claude Code version into a pure JavaScript (Node.js) build that runs on plain Node 18+. No Bun runtime required. Built on unbun.

Anthropic's Claude Code 2.1.112+ ships as a Bun --compile binary. cc2js downloads it, parses the embedded module graph with unbun, de-buns the entry bundle so it runs under Node, transpiles it to a single Node-compatible cli.js (Node 18 minimum), and bundles ripgrep plus the runtime deps Bun provided natively.

Quick start

Install cc2js globally (you must have Node.js first):

npm i -g cc2js

(Then run cc2js directly; or skip the install and use npx cc2js instead.)

Install / update the latest Claude Code as a cc2 command on your PATH:

cc2js          # = cc2js latest --link-name cc2
cc2            # run the Claude Code cc2js just installed
cc2 --version  # e.g. 2.1.199 (Claude Code)

Or just convert a version into a folder instead of installing (-o = don't install):

cc2js 2.1.185 -o ./cc
node ./cc/cli.js  # run the Claude Code cc2js just installed

Bake flags into the launcher (kept across updates; --no-cc-flags clears):

cc2js -- --dangerously-skip-permissions

List installed versions & links, or remove them:

cc2js ls
cc2js clean  # remove all; or: rm <version>, delink [name]

Why

Run Claude Code where the official binary cannot: old or constrained systems where the signed Bun binary or a new-enough Node refuses to launch, for example, a macOS 11 Intel MacBook (prebuilt Node 24+ dies with a libc++ error), old or minimal Linux (old glibc; the bundled ripgrep is the static musl build), or machines pinned to old Node (corporate images, LTS policies, CI bases). The cli.js cc2js emits runs on all of them (Node 18+).

Other uses:

• Read or audit the real cli.js source (esbuild reformats it; readable structure, though variable names stay mangled).
• Diff two releases' cli.js to see what changed.
• Patch or customize through the editable Bun-to-Node shim.
• Debug under node --inspect, profilers, coverage, or custom loaders.
• Smaller footprint (about 35 MB versus the 220 MB binary).
• Reproducible, air-gapped installs: build once, run later with only Node.
• Pin and keep multiple versions side by side.

Native addons and rg are platform-specific, so build with --platform for your target. The JavaScript core is platform-independent.

Usage

npm i -g cc2js to install, then:

cc2js [<version|latest|stable|tarball|binary>] [options]
cc2js                  install/update the latest as `cc2` (= cc2js latest)
cc2js ls | rm <version> | delink [name] | clean   manage installed versions & links

Any version installs by default (to ~/.cc2js, as `cc2` on PATH); pass -o to get a folder instead.

Input:
  <version>            e.g. 2.1.185, or "latest" / "stable".
                       Downloaded from downloads.claude.ai (falls back to GitHub, then npm).
  <tarball|binary>     a claude-*.tar.gz or an already-extracted Bun `claude` binary.

Options:
      --no-link        just convert to a folder; install no `cc2` command
      --link-name <n>  name the installed command (default: cc2)
      --bin-dir <dir>  where the launcher goes (default: ~/.local/bin, or %USERPROFILE%\.cc2js\bin on Windows)
      --no-add-path    don't persist the bin dir onto PATH (when linking; default: do)
  -t, --target <t>     transpile target (nodeXX, node18+); default: the Node running cc2js
  -p, --platform <p>   target platform (default: this host)
  -o, --out <dir>      convert into <dir> (implies --no-link unless --link-name given)
  -f, --force          re-convert even if cached; overwrite a foreign launcher
      --no-ripgrep     do not bundle ripgrep
      --no-install     do not npm install runtime deps into the output
      --keep-temp      keep the temp work dir
  -- <flags>           bake Claude flags into the launcher; preserved across updates
      --no-cc-flags    clear baked flags
  -h, --help / -v, --version

Platforms: linux-x64, linux-x64-musl, linux-arm64, linux-arm64-musl, darwin-x64, darwin-arm64, win32-x64, win32-arm64.

Management:
  cc2js ls             list installed versions + links
  cc2js rm <version>   remove a version (cascades delink)
  cc2js delink [name]  remove a launcher (default: cc2)
  cc2js clean          remove all versions + links (prompts y/N, or --yes)
  (all accept --bin-dir <dir>)

With -o <dir> (or --no-link) cc2js converts into a folder containing cli.js, bun-shim.cjs, the *.node addons, rg (rg.exe on Windows), a package.json, and a node_modules (ws, undici, ajv, ajv-formats). cli.js runs on the transpile target and newer (default: the Node you ran cc2js with; use -t node18 for the most portable build). Config is read from ~/.claude, like the official build.

By default (no -o) the build instead goes to ~/.cc2js/versions/ and a launcher (default cc2) lands in ~/.local/bin (on Windows: cc2.cmd + cc2.ps1 + a Git Bash cc2 in %USERPROFILE%\.cc2js\bin). If that dir isn't already on your PATH, cc2js adds it for you — the Windows user PATH (via the environment API, not setx), or your bash/zsh rc — then you open a new terminal to pick it up (an already-open shell can't be changed by any process). It never adds a duplicate and leaves an already-working PATH untouched; --no-add-path opts out (prints the line instead), and fish/tcsh always get a correct manual line.

Each install/update reports its outcome: linked (first time), updated (old → new), or unchanged (already current).

How it works

1. Download the Bun binary from downloads.claude.ai (SHA-256 checked; GitHub and npm fallbacks).
2. Parse the embedded module graph with unbun and take the entry module plus native addons.
3. De-bun cli.js: drop the // @bun directive, invoke the CommonJS wrapper Bun normally calls itself, and prepend bun-shim.cjs (a Node reimplementation of the Bun.* APIs).
4. Transpile to Node 18 with esbuild (lowering using) and prepend small runtime polyfills, producing one cli.js that runs on Node 18 through 26+.
5. Add ripgrep and npm install the runtime deps.

Library API

import { convert } from 'cc2js';

const { version, outDir } = await convert({ input: '2.1.185', platform: 'linux-x64' });
console.log(version, outDir);

convert(options) resolves to { version, platform, outDir, modules }. Options: input (required), platform, out, ripgrep, install, keepTemp, log. Also exported: PLATFORMS, hostPlatform.

Development

npm install
npm run checkall   # tsc typecheck + biome lint + biome format check + unit tests (no writes)
npm run fixall     # biome autofix (lint + format)
npm test           # unit tests (tsx + node:test)
npm run build      # compile TypeScript to dist/
npm run e2e        # heavy: convert real releases and run cli.js across Node majors (network)
npm run release:patch   # vbt: bump, commit, tag vX.Y.Z, push → triggers the publish workflow (also :minor / :major)

CI runs checkall across Node 18–24 on push/PR.

License

MIT