Start Claude Code

Run Claude Code v2.1.88 from leaked source code - one command setup.

Quick Start

git clone https://github.com/yourname/start-claude-code.git
cd start-claude-code

# Set API key
export ANTHROPIC_API_KEY="sk-ant-xxx"

# Run!
./start.sh

First run will automatically install Bun, dependencies, and configure everything.

---

Usage

Interactive mode (terminal UI)

export ANTHROPIC_API_KEY="sk-ant-xxx"
./start.sh

Non-interactive mode (scripts/pipes)

export ANTHROPIC_API_KEY="sk-ant-xxx"
./start.sh -p "explain this code" --dangerously-skip-permissions < /dev/null

Use a third-party proxy

export ANTHROPIC_BASE_URL="https://your-proxy.com"   # Don't include /v1
export ANTHROPIC_API_KEY="your-key"
export DISABLE_PROMPT_CACHING=1

./start.sh -p "hello" --model claude-sonnet-4-20250514 \
  --dangerously-skip-permissions --no-session-persistence < /dev/null

Specify model

./start.sh --model claude-sonnet-4-20250514
./start.sh --model claude-opus-4-20250514
./start.sh --model claude-haiku-4-5-20241022

---

Manual Setup

If you prefer to set up step by step:

# 1. Install Bun
curl -fsSL https://bun.sh/install | bash
export PATH="$HOME/.bun/bin:$PATH"

# 2. Run setup
node scripts/setup.mjs

# 3. Run
bun src/entrypoints/cli.tsx

---

Environment Variables

Variable	Description	Default
ANTHROPIC_API_KEY	Required. Your API key	-
ANTHROPIC_BASE_URL	API base URL (no /v1 suffix)	https://api.anthropic.com
ANTHROPIC_MODEL	Default model	claude-sonnet-4-6
DISABLE_PROMPT_CACHING	Disable prompt caching (needed for most proxies)	0
DISABLE_INTERLEAVED_THINKING	Disable interleaved thinking	0
CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS	Disable experimental beta headers	0

---

What is this?

On March 31, 2026, the full source code of Anthropic's Claude Code CLI was leaked via a .map file in their npm registry. This repository contains:

• The complete src/ directory (~1,900 files, 512,000+ lines of TypeScript)
• Build shims and stubs to make it runnable from source
• A one-click setup script

Source authenticity: Verified by comparing all 1,902 source files against @anthropic-ai/claude-code@2.1.88's source map — 100% byte-identical match, zero differences.

Tech Stack

Component	Technology
Runtime	Bun
Language	TypeScript
Terminal UI	React + Ink
CLI Parser	Commander.js
API	Anthropic SDK
Code Search	ripgrep (bundled)
Protocols	MCP, LSP

Source Structure

src/
├── main.tsx              # CLI entrypoint
├── QueryEngine.ts        # Core LLM API caller
├── tools/                # ~40 agent tools (Bash, Edit, Read, etc.)
├── commands/             # ~50 slash commands (/commit, /review, etc.)
├── components/           # ~140 Ink UI components
├── services/             # API, MCP, OAuth, analytics
├── bridge/               # IDE integration (VS Code, JetBrains)
├── coordinator/          # Multi-agent orchestration
├── skills/               # Skill system
├── plugins/              # Plugin system
├── memdir/               # Persistent memory
└── ...

---

Troubleshooting

"API Error: 400 ... invalid beta flag"

Your proxy doesn't support Claude beta headers. The code auto-disables betas for non-Anthropic URLs, but you can also set:

export CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1
export DISABLE_INTERLEAVED_THINKING=1

"API Error: 400 ... cache_control"

export DISABLE_PROMPT_CACHING=1

"API Error: 400 ... /v1/v1/messages"

Your ANTHROPIC_BASE_URL should NOT include /v1:

# Wrong
export ANTHROPIC_BASE_URL="https://proxy.com/v1"

# Correct
export ANTHROPIC_BASE_URL="https://proxy.com"

Stuck / no output in non-interactive mode

Always pipe /dev/null to stdin:

bun src/entrypoints/cli.tsx -p "hello" < /dev/null

---

Disclaimer

This repository archives source code that was leaked from Anthropic's npm registry. All original source code is the property of Anthropic.