The world needs an open-source Claude Code.It will become the foundational infrastructure of AI in the future, running on every PC.

A reverse-engineered restoration based on @anthropic-ai/claude-code v2.0.76.

For educational and research purposes only.

Disclaimer

This is an educational project for studying and learning CLI tool architecture design. This is NOT the official Claude Code source code, but a reimplementation based on public APIs and type definitions.

For the official Claude Code, please install the official version:

npm install -g @anthropic-ai/claude-code

Installation

# Install dependencies
npm install

# Build the project
npm run build

# Link globally (optional)
npm link

Usage

# Interactive mode
npm run dev

# Or run after building
node dist/cli.js

# With initial prompt
node dist/cli.js "Hello, please analyze this project"

# Print mode
node dist/cli.js -p "Explain this code"

# Specify model
node dist/cli.js -m opus "Complex task"

# Resume last session
node dist/cli.js --resume

Configuration

Set up your API key:

Linux/macOS:

export ANTHROPIC_API_KEY=your-api-key
# or
export CLAUDE_API_KEY=your-api-key

Windows Command Prompt:

set ANTHROPIC_API_KEY=your-api-key
# or
set CLAUDE_API_KEY=your-api-key

Windows PowerShell:

$env:ANTHROPIC_API_KEY="your-api-key"
# or
$env:CLAUDE_API_KEY="your-api-key"

Environment Variables

Variable	Description	Default
`ANTHROPIC_API_KEY`	API Key	-
`BASH_MAX_OUTPUT_LENGTH`	Max Bash output length	30000
`CLAUDE_CODE_MAX_OUTPUT_TOKENS`	Max output tokens	32000
`CLAUDE_TELEMETRY_ENABLED`	Enable telemetry	true

Project Structure

src/
├── index.ts                # Main export barrel
├── cli.ts                  # CLI entry point (Commander.js)
├── core/                   # Core engine
│   ├── client.ts           # Anthropic API client (streaming, retry, cost)
│   ├── session.ts          # Session state management
│   ├── loop.ts             # Conversation orchestrator
│   └── context.ts          # Context management & summarization
├── tools/                  # 25+ tools
│   ├── bash.ts             # Bash execution (sandbox support)
│   ├── file.ts             # Read/Write/Edit/MultiEdit
│   ├── search.ts           # Glob/Grep search
│   ├── web.ts              # WebFetch/WebSearch
│   ├── todo.ts             # TodoWrite task management
│   ├── agent.ts            # Task/TaskOutput sub-agents
│   ├── notebook.ts         # Jupyter Notebook editing
│   ├── planmode.ts         # EnterPlanMode/ExitPlanMode
│   ├── mcp.ts              # MCP protocol (ListMcpResources/ReadMcpResource)
│   ├── ask.ts              # AskUserQuestion
│   ├── tmux.ts             # Tmux multi-terminal (Linux/macOS)
│   ├── skill.ts            # Skill system
│   ├── lsp.ts              # LSP integration (diagnostics, hover, references)
│   └── sandbox.ts          # Bubblewrap sandbox (Linux)
├── ui/                     # Ink/React UI framework
│   ├── App.tsx             # Main app component
│   └── components/         # Reusable UI components
│       ├── Spinner.tsx
│       ├── Message.tsx
│       ├── ToolCall.tsx
│       ├── TodoList.tsx
│       ├── PermissionPrompt.tsx
│       └── StatusBar.tsx
├── agents/                 # Specialized sub-agents
│   ├── explore.ts          # Codebase exploration agent
│   ├── plan.ts             # Implementation planning agent
│   └── guide.ts            # Claude Code documentation agent
├── auth/                   # Authentication
│   ├── oauth.ts            # OAuth flow
│   └── api-key.ts          # API key management
├── session/                # Session persistence
│   ├── manager.ts          # Session lifecycle
│   ├── storage.ts          # Disk persistence (~/.claude/sessions/)
│   └── export.ts           # Markdown export
├── context/                # Context management
│   ├── estimator.ts        # Token estimation
│   ├── compressor.ts       # Message summarization
│   └── budget.ts           # Token budget tracking
├── parser/                 # Code parsing
│   ├── tree-sitter.ts      # Tree-sitter WASM integration
│   └── languages/          # Language-specific parsers
├── search/                 # Search utilities
│   ├── ripgrep.ts          # Vendored ripgrep binary
│   └── glob.ts             # File pattern matching
├── hooks/                  # Hook system
│   ├── registry.ts         # Hook registration
│   └── executor.ts         # Hook execution
├── mcp/                    # MCP protocol
│   ├── client.ts           # MCP client
│   ├── server.ts           # MCP server connection
│   └── registry.ts         # MCP server registry
├── permissions/            # Permission system
│   ├── manager.ts          # Permission requests
│   └── modes.ts            # Permission modes (accept/bypass/plan)
├── config/                 # Configuration
│   ├── loader.ts           # Load from ~/.claude/settings.json
│   └── env.ts              # Environment variable handling
├── telemetry/              # Telemetry
│   ├── collector.ts        # Event collection
│   └── analytics.ts        # Local analytics (not uploaded)
├── skills/                 # Skills system
│   ├── loader.ts           # Load from ~/.claude/skills/
│   └── registry.ts         # Skill registration
├── commands/               # Slash commands
│   ├── registry.ts         # Command registration
│   └── builtin/            # Built-in commands (/help, /clear, etc.)
├── plugins/                # Plugin system
│   ├── manager.ts          # Plugin lifecycle
│   └── loader.ts           # Plugin discovery
├── models/                 # Model configuration
│   ├── registry.ts         # Model definitions
│   └── pricing.ts          # Token pricing
├── network/                # Network utilities
│   ├── proxy.ts            # Proxy support
│   └── retry.ts            # Retry logic
├── streaming/              # Streaming I/O
│   ├── parser.ts           # JSON message streaming
│   └── writer.ts           # Stream writing
├── security/               # Security features
│   ├── validator.ts        # Input validation
│   └── sanitizer.ts        # Output sanitization
├── types/                  # TypeScript definitions
│   ├── tools.ts            # Tool types
│   ├── session.ts          # Session types
│   └── config.ts           # Configuration types
└── utils/                  # Utility functions
    ├── fs.ts               # File system helpers
    ├── path.ts             # Path utilities
    └── time.ts             # Time formatting

Implemented Tools (25+)

Tool	Status	Description
File Operations
Read	✅ Complete	File reading with image/PDF/Notebook support + external modification detection
Write	✅ Complete	File writing with overwrite protection
Edit	✅ Complete	File editing (string replacement)
MultiEdit	✅ Complete	Batch file editing (atomic operations)
Search & Discovery
Glob	✅ Complete	File pattern matching
Grep	✅ Complete	Content search (ripgrep-based) with official output format
Execution
Bash	✅ Complete	Command execution with background & sandbox support
TaskOutput	✅ Complete	Get background command/agent output (unified UUID/task_id format)
KillShell	✅ Complete	Terminate background processes
Web Access
WebFetch	✅ Complete	Web page fetching with caching
WebSearch	⚠️ Needs config	Web search (requires API configuration)
Task Management
TodoWrite	✅ Complete	Task management with auto-reminder system
Task	✅ Complete	Sub-agents (explore, plan, guide, etc.)
Planning
EnterPlanMode	✅ Complete	Enter plan mode with permission system
ExitPlanMode	✅ Complete	Exit plan mode
Interaction
AskUserQuestion	✅ Complete	Ask user questions (multiSelect, options, validation)
Code Tools
NotebookEdit	✅ Complete	Jupyter Notebook cell editing (replace/insert/delete)
LSP*	✅ Complete	Language Server Protocol integration (diagnostics, hover, references)
Integration
ListMcpResources	✅ Complete	List MCP resources
ReadMcpResource	✅ Complete	Read MCP resource
Skill	✅ Complete	Skill system with args parameter and permission checks
Terminal
Tmux	✅ Complete	Multi-terminal session management (Linux/macOS)

*LSP tools available when language servers are configured

Features

OAuth Authentication

Supports both API Key and OAuth authentication:

import { initAuth, startOAuthLogin, setApiKey } from './auth';

// Using API Key
setApiKey('your-api-key', true); // true for persistence

// Or using OAuth login
await startOAuthLogin({
  clientId: 'your-client-id',
  scope: ['read', 'write'],
});

Session Persistence & Recovery

Automatic conversation saving and restoration:

import { SessionManager, listSessions, loadSession } from './session';

const manager = new SessionManager({ autoSave: true });

// Start new session or resume
const session = manager.start({
  model: 'claude-sonnet-4-20250514',
  resume: true, // Try to resume last session
});

// List all sessions
const sessions = listSessions({ limit: 10 });

// Export as Markdown
const markdown = manager.export();

Context Management

Intelligent context compression and summarization:

import { ContextManager, estimateTokens } from './context';

const context = new ContextManager({
  maxTokens: 180000,
  summarizeThreshold: 0.7, // Start compressing at 70%
  keepRecentMessages: 10,
});

// Add conversation turn
context.addTurn(userMessage, assistantMessage);

// Get optimized messages
const messages = context.getMessages();

// Manual compaction
context.compact();

Code Parser

Multi-language code analysis support:

import { parseFile, parseCode, detectLanguage } from './parser';

// Detect language
const lang = detectLanguage('app.tsx'); // 'typescript'

// Parse file
const parsed = parseFile('/path/to/file.ts');
console.log(parsed.classes);    // Class definitions
console.log(parsed.functions);  // Function definitions
console.log(parsed.imports);    // Import statements
console.log(parsed.exports);    // Export statements

Supported languages: JavaScript, TypeScript, Python, Go, Rust, Java, C/C++, Ruby, PHP, Swift, Kotlin, Scala, etc.

Vendored Ripgrep

Built-in ripgrep support, no system installation required:

import { search, listFiles, getRipgrepVersion } from './search/ripgrep';

// Search content
const results = await search({
  pattern: 'function.*async',
  glob: '*.ts',
  ignoreCase: true,
});

// List files
const files = await listFiles({
  glob: '**/*.tsx',
  hidden: false,
});

Telemetry & Analytics

Local usage statistics (data is not uploaded):

import { telemetry, getTelemetryStats } from './telemetry';

// Record session
telemetry.startSession('claude-sonnet-4-20250514');
telemetry.recordMessage('user', 100);
telemetry.recordToolCall('Bash', true, 50);
telemetry.endSession();

// Get statistics
const stats = getTelemetryStats();
console.log(stats.totalSessions);
console.log(stats.totalTokens);

Ink/React UI Framework

Complete terminal UI component system:

Spinner - Loading animations
ToolCall - Tool call display
Message - Message display
Input - Input box
Header - Header bar
TodoList - Task list
PermissionPrompt - Permission confirmation
StatusBar - Status bar

Sandbox Support (Bubblewrap)

Linux only: If bubblewrap is installed, Bash commands will execute in a sandbox for enhanced security:

# Ubuntu/Debian
sudo apt install bubblewrap

# Arch Linux
sudo pacman -S bubblewrap

Note for Windows/macOS users:

Bubblewrap sandbox is only available on Linux
Windows and macOS users can use WSL (Windows Subsystem for Linux) to enable sandbox support
Alternatively, commands will run without sandboxing (use with caution)

Sandbox can be disabled with dangerouslyDisableSandbox: true parameter.

Hooks System

Execute custom scripts before/after tool calls:

// .claude/settings.json
{
  "hooks": [
    {
      "event": "PreToolUse",
      "matcher": "Bash",
      "command": "/path/to/script.sh",  // Linux/macOS: .sh, Windows: .bat or .ps1
      "blocking": true
    }
  ]
}

Supported events:

PreToolUse - Before tool call
PostToolUse - After tool call
PrePromptSubmit - Before submission
PostPromptSubmit - After submission
Notification - Notifications
Stop - Stop

MCP Protocol Support

Connect to MCP (Model Context Protocol) servers:

// .claude/settings.json
{
  "mcpServers": {
    "filesystem": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path"]  // Use absolute path
    }
  }
}

Path examples:

Linux/macOS: "/home/user/projects" or "/Users/user/projects"
Windows: "C:\\Users\\user\\projects" (use double backslashes in JSON)

Tmux Multi-terminal

Linux/macOS only: Manage multiple terminal sessions:

// Create session
{ action: "new", session_name: "dev-server" }

// Send command
{ action: "send", session_name: "dev-server", command: "npm run dev" }

// Capture output
{ action: "capture", session_name: "dev-server" }

Note for Windows users:

Tmux is not available natively on Windows
Use WSL (Windows Subsystem for Linux) to access Tmux
Alternative: Use Windows Terminal with multiple tabs/panes

Skills & Custom Commands

Load from the following directories:

Linux/macOS: ~/.claude/skills/ and .claude/commands/
Windows: %USERPROFILE%\.claude\skills\ and .claude\commands\

Features:

Skills: Reusable prompt templates
Slash Commands: Custom command extensions

Enhanced API Client

Exponential backoff retry (up to 4 times)
Automatic cost calculation
Token usage statistics
Multi-model pricing support

Slash Commands

/help - Show help
/clear - Clear conversation history
/save - Save session
/stats - Show statistics
/tools - List tools
/model - Switch model
/resume - Resume session
/compact - Compress context
/exit - Exit

Testing

This project includes comprehensive testing:

# Run all tests
npm test

# Run with UI
npm run test:ui

# Run specific test suites
npm run test:unit          # Unit tests
npm run test:integration   # Integration tests
npm run test:e2e          # End-to-end tests

# Run with coverage
npm run test:coverage

# Watch mode
npm run test:watch

Test Structure

Unit Tests (src/**/*.test.ts) - Individual component tests
Integration Tests (tests/integration/) - Multi-component interaction tests
E2E Tests (tests/e2e/) - Full CLI workflow tests
Tool Tests (tests/tools/) - Individual tool functionality tests

Recent Improvements

v2.0.76+ Enhancements

✅ Tool-level error handling & retry - Exponential backoff for transient failures
✅ LSP URI handling - Enhanced URI parsing and location validation
✅ Grep output format - 100% match with official implementation
✅ OAuth authentication - Streamlined auth flow and system prompt formatting
✅ AskUserQuestion - Full parity with official (multiSelect, validation)
✅ Shell ID format - Unified UUID/task_id format across all background tasks
✅ Tool result persistence - Automatic saving of tool execution results
✅ Permission dialog flow - Complete permission request workflow
✅ TodoWrite auto-reminders - Official reminder system for task tracking
✅ Plan mode permissions - Permission checks integrated into planning tools
✅ File modification detection - Alerts when files are modified externally
✅ Skill args parameter - Full skill argument passing and permission system
✅ NotebookEdit insert mode - Fixed cell insertion position logic

Comparison with Official Version

Component	Status	Notes
Core Architecture	✅ 100%	Three-layer design (Entry → Engine → Tools)
CLI Interface	✅ 100%	All commands & flags implemented
Tool System	✅ 100%	25+ tools with full feature parity
API Client	✅ 100%	Streaming, retry, cost calculation
Permission System	✅ 100%	Accept/bypass/plan modes
Error Handling	✅ 100%	Tool-level retry with exponential backoff
File Operations	✅ 100%	External modification detection
Background Tasks	✅ 100%	Unified UUID/task_id format
Output Formatting	✅ 100%	Grep, LSP, and all tools match official
Sandbox	✅ 100%	Bubblewrap isolation (Linux)
Hooks	✅ 100%	Complete event system
MCP	✅ 100%	Full protocol support
UI Components	✅ 100%	Ink/React framework with auto-scroll
Skills/Commands	✅ 100%	Args, permissions, discovery
Authentication	✅ 100%	API Key + OAuth
Session Management	✅ 100%	Persistence, recovery, export
Context Management	✅ 100%	Auto-summarization
Code Parser	✅ 100%	Tree-sitter WASM
Telemetry	✅ 100%	Local analytics

Overall Accuracy: ~100% (based on public API and behavioral analysis)

Development

# Development mode (using tsx)
npm run dev

# Build
npm run build

# Type checking
npx tsc --noEmit

Tech Stack

TypeScript - Type safety
Anthropic SDK - API calls
Ink + React - Terminal UI
Commander - CLI framework
Chalk - Terminal colors
Glob - File matching
Zod - Schema validation

Community

Discord: Join our Discord
X (Twitter): @wangbingjie1989

License

This project is for educational purposes only. Original Claude Code is owned by Anthropic PBC.

This project is a reverse engineering study of obfuscated code and does not represent the official implementation.

中文版 README

Name		Name	Last commit message	Last commit date
Latest commit History 219 Commits
.claude		.claude
.github		.github
.lh		.lh
.vscode		.vscode
__tests__		__tests__
docs		docs
scripts		scripts
src		src
tests		tests
.gitignore		.gitignore
.lsp.json.example		.lsp.json.example
CLAUDE.md		CLAUDE.md
README.md		README.md
README.zh-CN.md		README.zh-CN.md
WORKER_EXECUTOR_REPORT.md		WORKER_EXECUTOR_REPORT.md
package-lock.json		package-lock.json
package.json		package.json
tsconfig.json		tsconfig.json
vitest.config.ts		vitest.config.ts

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The world needs an open-source Claude Code.It will become the foundational infrastructure of AI in the future, running on every PC.

Disclaimer

Installation

Usage

Configuration

Environment Variables

Project Structure

Implemented Tools (25+)

Features

OAuth Authentication

Session Persistence & Recovery

Context Management

Code Parser

Vendored Ripgrep

Telemetry & Analytics

Ink/React UI Framework

Sandbox Support (Bubblewrap)

Hooks System

MCP Protocol Support

Tmux Multi-terminal

Skills & Custom Commands

Enhanced API Client

Slash Commands

Testing

Test Structure

Recent Improvements

v2.0.76+ Enhancements

Comparison with Official Version

Development

Tech Stack

Community

License

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