Claude Code — recovered source tree

What this is

On 31 March 2026, developers reported that the published npm package for Anthropic’s Claude Code CLI shipped a large bundled cli.js together with a source map (.map). Because the map pointed back to original paths and content, the TypeScript/React implementation could be reconstructed from the registry artifact. This repository holds that kind of recovered src/ tree — useful for understanding architecture and integration, not an official release or supported SDK.

How it leaked

Chaofan Shou (@Fried_rice) discovered the leak and posted it publicly:

Claude code source code has been leaked via a map file in their npm registry!

— @Fried_rice, 31 March 2026

The source map file in the published npm package contained a reference to the full, unobfuscated TypeScript source, which was downloadable as a zip archive from Anthropic’s R2 storage bucket.

Overview

Claude Code is Anthropic’s official CLI tool that lets you interact with Claude directly from the terminal to perform software engineering tasks — editing files, running commands, searching codebases, managing git workflows, and more.

This repository contains the leaked src/ directory.

Property	Value
Leaked on	2026-03-31
Language	TypeScript
Runtime	Bun
Terminal UI	React + Ink (React for CLI)
Scale	~1,900 files, 512,000+ lines of code

Discussion and context: Hacker News thread on the npm source-map leak.

Legal / ethical note: The underlying software is Anthropic’s proprietary product. This README describes structure for analysis only; redistribution or use beyond fair use / your local law is your responsibility.

How the codebase fits together

The CLI is a Bun-bundled application whose spine is src/main.tsx: a Commander-based program named claude that registers global options, subcommands, and a preAction hook where trust, settings, telemetry gates, and prefetch work run before the interactive or print-mode loop.

Directory structure

The tree below matches this repo’s src/ layout. For root-level filenames, per-folder notes, and selected subtrees (services/, tools/, utils/), see docs/directory-structure.md.

src/
├── main.tsx
├── QueryEngine.ts
├── Task.ts
├── Tool.ts
├── commands.ts
├── context.ts
├── cost-tracker.ts
├── costHook.ts
├── dialogLaunchers.tsx
├── history.ts
├── ink.ts
├── interactiveHelpers.tsx
├── projectOnboardingState.ts
├── query.ts
├── replLauncher.tsx
├── setup.ts
├── tasks.ts
├── tools.ts
│
├── assistant/
├── bootstrap/
├── bridge/
├── buddy/
├── cli/
├── commands/
├── components/
├── constants/
├── context/
├── coordinator/
├── entrypoints/
├── hooks/
├── ink/
├── keybindings/
├── memdir/
├── migrations/
├── moreright/
├── native-ts/
├── outputStyles/
├── plugins/
├── query/
├── remote/
├── schemas/
├── screens/
├── server/
├── services/
├── skills/
├── state/
├── tasks/
├── tools/
├── types/
├── upstreamproxy/
├── utils/
├── vim/
└── voice/

High-level layers

Area	Role
main.tsx + cli/	Argument parsing, early startup (MDM/keychain prefetch side effects), routing to REPL, -p/--print, doctor, install, MCP helpers, etc.
replLauncher.js / components/ / ink/	Terminal UI built with React + Ink; dialogs, status, and input handling.
services/api/	HTTP client to Anthropic APIs, bootstrap, files, session ingress, usage, retries.
services/mcp/	Model Context Protocol: config parsing, stdio/SDK transports, connection manager, OAuth, enterprise/XAA paths.
services/compact/	Session compaction (memory/context management hooks the model loop).
services/lsp/	Optional LSP integration for editor-like features in the terminal workflow.
tools/	Tool implementations the agent invokes (bash, read/write, grep/glob, web, todos, tasks, teammates, MCP tools, etc.).
utils/swarm/	Multi-agent teammate flows: backends for tmux, iTerm, in-process runners, permission sync, reconnection.
coordinator/	Gated behind bundle feature COORDINATOR_MODE (multi-agent coordination).
assistant/	Gated behind bundle feature KAIROS (assistant / Agent SDK–oriented mode).
plugins/, skills/	Bundled and user plugins; skill loading and telemetry.
utils/settings/, services/policyLimits/, services/remoteManagedSettings/	Layered configuration, enterprise policy, and remote-managed settings.
buddy/, upstreamproxy/, voice/, vim/	Product features (buddy flows, upstream proxy, voice, vim-style editing).
utils/deepLink/, utils/claudeInChrome/	OS integration: URL schemes, Chrome native messaging, optional MCP entrypoints.

Execution paths converge on shared state (state/, bootstrap/), permissions (utils/permissions/), and session storage (utils/sessionStorage.js, hooks in utils/sessionStart.js). Non-interactive and SDK-style use share much of the same stack as the full-screen REPL, with different front-ends for I/O.

Documentation (GitHub Pages)

Full internals documentation is built with MkDocs Material from docs-site/. The site includes system design (layers, state flow, security/trust), architecture overview and workflows, a developer hub (editing docs, navigating src/, Bun feature flags), guides for greenfield agentic CLI and docs/CI patterns, reference pages per subsystem, official docs map, and appendices (directory layout, tools, env vars, glossary).

• Live site: https://mehmoodosman.github.io/claude-code-source-code/
• Local preview: cd docs-site && python3 -m venv .venv && source .venv/bin/activate && pip install -r requirements.txt && mkdocs serve
• Publish: pushing to main runs .github/workflows/pages.yml and deploys to gh-pages.

Canonical site_url and repo_url are set in docs-site/mkdocs.yml for this deployment. Forks should change those values to match their own GitHub user/org and Pages URL.

Contributing to docs: edit Markdown under docs-site/docs/; keep the official docs map in sync with Anthropic’s docs index when adding major features.

Next steps (forks / new clones)

1. Commit and push so main includes docs-site/ and .github/workflows/pages.yml.
2. Run the Pages workflow (or wait for it on push).
3. Settings → Pages → deploy from branch gh-pages / / (root) (unless you switch to the GitHub Actions Pages source).
4. Set site_url in mkdocs.yml to your live URL and align repo_url / extra.social with your fork, then push to refresh the site.

Repository layout

• src/ — Application source (thousands of modules) as recovered from the bundle map.
• docs-site/ — MkDocs source for the GitHub Pages documentation site.
• docs/ — Short pointer plus directory-structure.md (src/ layout reference).
• scripts/ — Optional helpers (e.g. gen-appendices.sh).
• There is no package.json in this clone; building would require the original toolchain (Bun, internal bun:bundle features, and private deps). Treat this tree as a read-only architectural reference.