March 31, 2026
When a source map spills the tea
Claude Code full source code leaked on NPM
Dev world split: “dupe!” cries vs “it builds!” cheers as Claude Code source resurfaces
TLDR: Anthropic’s Claude Code source surfaced via a source map in its JavaScript package on NPM (the public registry), now mirrored by an unofficial repo. Commenters argue “duplicate” vs “better build,” say the code looks fine, and demand release‑process details—showing how fast, imperfect AI tools are shipped.
Popcorn time: Anthropic’s Claude Code command‑line tool just had its readable source pop out of an official release after someone unpacked the included “source map” (a file that maps the app back to its original code). An unofficial repo now mirrors the code with a big “this is Anthropic’s IP” disclaimer and zero affiliation, while the official page sits here: anthropics/claude-code.
The comments? Pure chaos. One camp yells “dupe!”, dropping a link to a previous thread on Hacker News. The other camp fires back: this one actually builds, unlike that earlier drop. Cue the dupe police vs build‑braggers showdown.
Amid the squabble, a surprising vibe: the code isn’t a disaster. One dev shrugs, “seen much shadier ‘vibe‑coded’ projects,” then pivots to the real tea—how does Anthropic ship so fast? People want the release playbook: if a lead claims “10+ pull requests a day,” what triggers a release, and why doesn’t every change go live? Theories swirl: a secret “release fairy,” Friday ship‑it roulette, or just grown‑up CI (continuous integration) discipline.
Jokes fly about “accidentally gift‑wrapping your source in the package,” but the mood is oddly respectful: interesting code, interesting process, messy packaging. It’s part drama, part workshop—equal parts “gotcha” and “teach me your release rituals.”
Key Points
- •An unofficial repository extracted the TypeScript source of Anthropic’s Claude Code CLI from the cli.js.map included in the npm package @anthropic-ai/claude-code v2.1.88.
- •The project asserts it is not affiliated with Anthropic and provides the code for educational and reference purposes only.
- •Detailed instructions show how to reproduce the extraction using npm pack and a Node.js script to parse cli.js.map and write the sources to disk.
- •A project structure overview lists key directories and files, including CLI, commands, components (Ink/React), services, tools, and types.
- •The repository reiterates that Anthropic owns the code and users should follow Anthropic’s license terms.