Claude Code Source Snapshot

An exploratory mirror of a source snapshot reportedly exposed via published source maps on March 31, 2026

Also check out these two cool projects:

1. claude_agent_teams_ui - You're the CTO, agents are your team. They handle tasks themselves, message each other, review each other's code. You just look at the kanban board and drink coffee.
2. claude-notifications-go - 🔔 Cross-platform smart notifications plugin for Claude Code. 6 types. Click-to-focus. 1 line installation.

The raw imported snapshot is preserved in this repository's backup branch. The main branch contains added documentation, tooling, and repository metadata.

Table of Contents

• How It Leaked
• What Is Claude Code?
• Documentation
• Explore with MCP Server
• Directory Structure
• Architecture
  • Tool System
  • Command System
  • Service Layer
  • Bridge System
  • Permission System
  • Feature Flags
• Key Files
• Tech Stack
• Design Patterns
• GitPretty Setup
• Contributing
• Disclaimer

How It Leaked

Chaofan Shou (@Fried_rice) discovered that the published npm package for Claude Code included a .map file referencing the full, unobfuscated TypeScript source — downloadable as a zip from Anthropic's R2 storage bucket.

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

— @Fried_rice, March 31, 2026

What Is Claude Code?

Claude Code is Anthropic's official CLI tool for interacting with Claude directly from the terminal: editing files, running commands, searching codebases, managing git workflows, and more. This repository contains a source snapshot together with added docs, MCP tooling, and repository metadata to help inspect it.

Documentation

For in-depth guides, see the docs/ directory:

Also see: CONTRIBUTING.md · MCP Server README

Explore with MCP Server

This repo also ships an MCP server that lets any MCP-compatible client (Claude Code, Claude Desktop, VS Code Copilot, Cursor) explore the snapshot interactively.

Install from npm

The MCP server is published as claude-code-explorer-mcp on npm — no need to clone the repo:

# Claude Code
claude mcp add claude-code-explorer -- npx -y claude-code-explorer-mcp

One-liner setup (from source)

git clone https://github.com/777genius/claude-code-source-code.git ~/claude-code-source-code \
  && cd ~/claude-code-source-code/mcp-server \
  && npm install && npm run build \
  && claude mcp add claude-code-explorer -- node ~/claude-code-source-code/mcp-server/dist/index.js

# 1. Clone the repo
git clone https://github.com/777genius/claude-code-source-code.git
cd claude-code-source-code/mcp-server

# 2. Install & build
npm install && npm run build

# 3. Register with Claude Code
claude mcp add claude-code-explorer -- node /absolute/path/to/claude-code-source-code/mcp-server/dist/index.js

Replace /absolute/path/to/claude-code-source-code with your actual clone path.

VS Code — add to .vscode/mcp.json:

{
  "servers": {
    "claude-code-explorer": {
      "type": "stdio",
      "command": "node",
      "args": ["${workspaceFolder}/mcp-server/dist/index.js"],
      "env": { "CLAUDE_CODE_SRC_ROOT": "${workspaceFolder}/src" }
    }
  }
}

Claude Desktop — add to your config file:

{
  "mcpServers": {
    "claude-code-explorer": {
      "command": "node",
      "args": ["/absolute/path/to/claude-code-source-code/mcp-server/dist/index.js"],
      "env": { "CLAUDE_CODE_SRC_ROOT": "/absolute/path/to/claude-code-source-code/src" }
    }
  }
}

Cursor — add to ~/.cursor/mcp.json (same format as Claude Desktop).

Available tools & prompts

Try asking: "How does the BashTool work?" · "Search for where permissions are checked" · "Show me the /review command source"

Custom source path / Remove

# Custom source location
claude mcp add claude-code-explorer -e CLAUDE_CODE_SRC_ROOT=/path/to/src -- node /path/to/mcp-server/dist/index.js

# Remove
claude mcp remove claude-code-explorer

Directory Structure

src/
├── main.tsx                 # Entrypoint — Commander.js CLI parser + React/Ink renderer
├── QueryEngine.ts           # Core LLM API caller (~46K lines)
├── Tool.ts                  # Tool type definitions (~29K lines)
├── commands.ts              # Command registry (~25K lines)
├── tools.ts                 # Tool registry
├── context.ts               # System/user context collection
├── cost-tracker.ts          # Token cost tracking
│
├── tools/                   # Agent tool implementations (~40)
├── commands/                # Slash command implementations (~50)
├── components/              # Ink UI components (~140)
├── services/                # External service integrations
├── hooks/                   # React hooks (incl. permission checks)
├── types/                   # TypeScript type definitions
├── utils/                   # Utility functions
├── screens/                 # Full-screen UIs (Doctor, REPL, Resume)
│
├── bridge/                  # IDE integration (VS Code, JetBrains)
├── coordinator/             # Multi-agent orchestration
├── plugins/                 # Plugin system
├── skills/                  # Skill system
├── server/                  # Server mode
├── remote/                  # Remote sessions
├── memdir/                  # Persistent memory directory
├── tasks/                   # Task management
├── state/                   # State management
│
├── voice/                   # Voice input
├── vim/                     # Vim mode
├── keybindings/             # Keybinding configuration
├── schemas/                 # Config schemas (Zod)
├── migrations/              # Config migrations
├── entrypoints/             # Initialization logic
├── query/                   # Query pipeline
├── ink/                     # Ink renderer wrapper
├── buddy/                   # Companion sprite (Easter egg 🐣)
├── native-ts/               # Native TypeScript utils
├── outputStyles/            # Output styling
└── upstreamproxy/           # Proxy configuration

Architecture

1. Tool System

src/tools/ — Every tool Claude can invoke is a self-contained module with its own input schema, permission model, and execution logic.

2. Command System

src/commands/ — User-facing slash commands invoked with / in the REPL.

3. Service Layer

src/services/ — External integrations and core infrastructure.

4. Bridge System

src/bridge/ — Bidirectional communication layer connecting IDE extensions (VS Code, JetBrains) with the CLI.

Key files: bridgeMain.ts (main loop) · bridgeMessaging.ts (protocol) · bridgePermissionCallbacks.ts (permission callbacks) · replBridge.ts (REPL session) · jwtUtils.ts (JWT auth) · sessionRunner.ts (session execution)

5. Permission System

src/hooks/toolPermission/ — Checks permissions on every tool invocation.

Prompts the user for approval/denial or auto-resolves based on the configured permission mode: default, plan, bypassPermissions, auto, etc.

6. Feature Flags

Dead code elimination at build time via Bun's bun:bundle:

import { feature } from 'bun:bundle'

const voiceCommand = feature('VOICE_MODE')
  ? require('./commands/voice/index.js').default
  : null

Notable flags: PROACTIVE · KAIROS · BRIDGE_MODE · DAEMON · VOICE_MODE · AGENT_TRIGGERS · MONITOR_TOOL

Key Files

Tech Stack

Design Patterns

MDM settings, keychain reads, and API preconnect fire in parallel as side-effects before heavy module evaluation:

// main.tsx
startMdmRawRead()
startKeychainPrefetch()

OpenTelemetry (~400KB) and gRPC (~700KB) are loaded via dynamic import() only when needed.

Sub-agents spawn via AgentTool, with coordinator/ handling orchestration. TeamCreateTool enables team-level parallel work.

Defined in skills/ and executed through SkillTool. Users can add custom skills.

Built-in and third-party plugins loaded through the plugins/ subsystem.

GitPretty Setup

# Apply emoji commits
bash ./gitpretty-apply.sh .

# Optional: install hooks for future commits
bash ./gitpretty-apply.sh . --hooks

# Push as usual
git push origin main

Contributing

Contributions to documentation, the MCP server, and exploration tooling are welcome. Changes to the archived snapshot under src/ are not the default contribution path. See CONTRIBUTING.md for guidelines.

Note: The src/ directory is the archived source snapshot and should generally remain unchanged.

Disclaimer

This repository archives a source snapshot reportedly exposed via Anthropic's npm distribution on 2026-03-31. It is provided for research, documentation, and exploratory tooling around the snapshot. The original Claude Code source remains the property of Anthropic, this is not an official release, and no rights to Anthropic's original code are granted by this repository. If you choose to use or redistribute any of the archived material, you are responsible for assessing the legal implications yourself. Contact nichxbt for any comments.