Claude Code Go

Claude Code Go

🤖 A Go reimplementation of Claude Code — AI coding assistant in your terminal

English • 简体中文 • 日本語 • 한국어 • Español • Français

---

Interactive TUI with file reading and real-time thinking display

Comprehensive project analysis with architecture breakdown

---

What is this?

This project is a complete Go reimplementation of Claude Code — Anthropic's official TypeScript CLI — rewritten module-by-module in Go, covering all core features: TUI, tool use, permission system, multi-agent coordination, MCP protocol, session management, and more.

Built entirely by AI agents — zero human-written code

> No human wrote a single line of production code in this repository.

The entire project — architecture design, detailed design docs, parallel implementation, code review, QA, and integration testing — was produced by 9 Claude AI agents collaborating in a structured multi-agent workflow:

PM Agent          →  project plan, milestones, task scheduling
Tech Lead Agent   →  architecture design, design-doc review, code review
Agent-Infra       →  infrastructure layer (types, config, state, session)
Agent-Services    →  services layer (API client, OAuth, MCP, compaction)
Agent-Core        →  core engine (LLM loop, tool dispatch, coordinator)
Agent-Tools       →  tools layer (file, shell, search, web — 18 tools)
Agent-TUI         →  UI layer (Bubble Tea MVU, themes, Vim mode)
Agent-CLI         →  entry layer (Cobra CLI, DI, bootstrap phases)
QA Agent          →  test strategy, per-layer acceptance, integration tests

Each agent worked on an isolated Git Worktree branch in parallel, collaborating through the shared codebase, design docs, and QA reports. The result: ~7,000 lines of production code + a full test suite, with go test -race ./... passing.

This is a real-world demonstration that a non-trivial, multi-layer Go application can be fully designed, implemented, reviewed, and shipped by AI agents collaborating asynchronously. The complete decision trail lives in [docs/project/](docs/project/).

---

A Go implementation of Claude Code — an agentic AI coding assistant that lives in your terminal. Claude Code understands your codebase, runs tools, and helps you write, review, and refactor code through natural conversation.

Features

• Interactive TUI — Full-featured terminal UI built with Bubble Tea, with dark/light themes
• Agentic tool use — File reads/writes, shell execution, search, and more, all mediated through a permission layer
• Multi-agent coordination — Spawn background sub-agents for parallel tasks
• MCP support — Connect external tools via the Model Context Protocol
• CLAUDE.md memory — Auto-loads project context from CLAUDE.md files up the directory tree
• Session management — Resume previous conversations; compact long histories automatically
• Vim mode — Optional Vim key bindings in the input area
• OAuth + API key auth — Sign in with Anthropic OAuth or supply an ANTHROPIC_API_KEY
• 18 built-in slash commands — /help, /clear, /compact, /commit, /diff, /review, /mcp, and more
• Streaming responses — Real-time token streaming with thinking-block display

Architecture

Claude Code Go is organized in six layers:

┌─────────────────────────────────────┐
│  CLI (cmd/claude)                   │  cobra entry point
├─────────────────────────────────────┤
│  TUI (internal/tui)                 │  Bubble Tea MVU interface
├─────────────────────────────────────┤
│  Tools (internal/tools)             │  file, shell, search, MCP tools
├─────────────────────────────────────┤
│  Core Engine (internal/engine)      │  streaming, tool dispatch, coordinator
├─────────────────────────────────────┤
│  Services (internal/api, oauth,     │  Anthropic API, OAuth, MCP client
│            mcp, compact)            │
├─────────────────────────────────────┤
│  Infra (pkg/types, internal/config, │  types, config, state, hooks, plugins
│         state, session, hooks)      │
└─────────────────────────────────────┘

See [docs/project/architecture.md](docs/project/architecture.md) for a detailed breakdown.

Requirements

• Go 1.21 or later
• An Anthropic API key or Claude.ai account (OAuth)

Installation

From source

git clone https://github.com/tunsuy/claude-code-go.git
cd claude-code-go
make build
# Binary is placed at ./bin/claude

Add to your PATH:

export PATH="$PATH:$(pwd)/bin"

Using go install

go install github.com/tunsuy/claude-code-go/cmd/claude@latest

Quick Start

# Set your API key (or use OAuth — see Authentication below)
export ANTHROPIC_API_KEY=sk-ant-...

# Start an interactive session in the current directory
claude

# Ask a one-shot question and exit
claude -p "Explain the main entry point of this project"

# Resume the most recent session
claude --resume

Authentication

API key (recommended for CI/scripts):

export ANTHROPIC_API_KEY=sk-ant-...

OAuth (recommended for interactive use):

claude /config    # opens the OAuth flow in your browser

API Providers

Claude Code Go supports multiple API providers, allowing you to use not just Anthropic's API, but also OpenAI-compatible APIs.

Supported Providers

| Provider | Description | Environment Variables | |----------|-------------|----------------------| | direct (default) | Anthropic Direct API | ANTHROPIC_API_KEY, ANTHROPIC_BASE_URL | | openai | OpenAI & compatible APIs | OPENAI_API_KEY, OPENAI_BASE_URL | | bedrock | AWS Bedrock | AWS credentials via environment | | vertex | Google Cloud Vertex AI | GCP credentials via environment |

Using OpenAI-Compatible APIs

To use OpenAI, DeepSeek, Qwen, Moonshot, or any OpenAI-compatible API:

Method 1: Environment Variables

# Set provider to openai
export CLAUDE_PROVIDER=openai

# Set your API key
export OPENAI_API_KEY=sk-xxx

# Optionally set a custom base URL (for OpenAI-compatible services)
export OPENAI_BASE_URL=https://api.deepseek.com  # DeepSeek
# export OPENAI_BASE_URL=https://api.moonshot.cn/v1  # Moonshot
# export OPENAI_BASE_URL=http://localhost:11434/v1  # Ollama

# Set the model
export OPENAI_MODEL=deepseek-chat

# Run Claude Code
claude

Method 2: Configuration File

Create or edit ~/.config/claude-code/settings.json:

{
  "provider": "openai",
  "apiKey": "sk-xxx",
  "baseUrl": "https://api.openai.com",
  "model": "gpt-4-turbo",
  "openaiOrganization": "org-xxx",
  "openaiProject": "proj-xxx"
}

Provider-Specific Notes

OpenAI:

• Supports all GPT-4 and GPT-3.5 models
• Full tool/function calling support
• Streaming responses

DeepSeek:

export CLAUDE_PROVIDER=openai
export OPENAI_API_KEY=sk-xxx
export OPENAI_BASE_URL=https://api.deepseek.com
export OPENAI_MODEL=deepseek-chat

Ollama (local):

export CLAUDE_PROVIDER=openai
export OPENAI_BASE_URL=http://localhost:11434/v1
export OPENAI_MODEL=llama3

Azure OpenAI:

export CLAUDE_PROVIDER=openai
export OPENAI_API_KEY=your-azure-key
export OPENAI_BASE_URL=https://your-resource.openai.azure.com
export OPENAI_MODEL=your-deployment-name

Usage

Interactive mode

claude [flags]

| Flag | Description | |------|-------------| | --resume | Resume the most recent session | | --session | Resume a specific session by ID | | --model | Override the default Claude model | | --dark / --light | Force dark or light theme | | --vim | Enable Vim key bindings | | -p, --print | Non-interactive: run a single prompt and exit |

Slash commands

Type / in the input to see all available commands:

| Command | Description | |---------|-------------| | /help | Show all commands | | /clear | Clear conversation history | | /compact | Summarise history to reduce context usage | | /exit | Exit Claude Code | | /model | Switch Claude model | | /theme | Toggle dark/light theme | | /vim | Toggle Vim mode | | /commit | Generate a git commit message | | /review | Review recent changes | | /diff | Show current diff | | /mcp | Manage MCP servers | | /memory | Show loaded CLAUDE.md files | | /session | Show session info | | /status | Show API/connection status | | /cost | Show token usage and estimated cost |

Development

Prerequisites

• Go 1.21+
• golangci-lint (optional, for linting)

Build & test

# Build
make build

# Run all tests
make test

# Run tests with coverage report
make test-cover

# Vet
make vet

# Lint (requires golangci-lint)
make lint

# Build + test + vet
make all

Project layout

claude-code-go/
├── cmd/claude/          # CLI entry point
├── internal/
│   ├── api/             # Anthropic API client & streaming
│   ├── bootstrap/       # App initialisation
│   ├── commands/        # Slash command handlers
│   ├── compact/         # Conversation compaction
│   ├── config/          # Configuration (file + env)
│   ├── coordinator/     # Multi-agent coordinator
│   ├── engine/          # Query engine, tool dispatch
│   ├── hooks/           # Pre/post-tool hooks
│   ├── mcp/             # MCP server management
│   ├── memdir/          # CLAUDE.md loader
│   ├── oauth/           # OAuth2 flow
│   ├── permissions/     # Tool permission layer
│   ├── plugin/          # Plugin system
│   ├── session/         # Session persistence
│   ├── state/           # Application state
│   ├── tools/           # Tool interface, registry & built-in implementations
│   │   ├── agent/       #   sub-agent & send-message tools
│   │   ├── fileops/     #   file read/write/edit/glob/grep tools
│   │   ├── interact/    #   user-interaction & worktree tools
│   │   ├── mcp/         #   MCP tool adapter
│   │   ├── misc/        #   miscellaneous tools
│   │   ├── shell/       #   Bash execution tool
│   │   ├── tasks/       #   task-list tools
│   │   └── web/         #   web fetch & search tools
│   └── tui/             # Bubble Tea UI components
├── pkg/
│   └── types/           # Shared public types
├── docs/                # Design docs and QA reports
├── Makefile
└── go.mod

Roadmap

Claude Code Go is currently at ~65% feature parity with the original TypeScript version. Here's our phased plan to reach v1.0:

| Phase | Version | Key Goals | Timeline | |-------|---------|-----------|----------| | Phase 1 | v0.2.0 | 🔒 Permission system integration, Hook system wiring, test coverage baseline, CI hardening | +3 weeks | | Phase 2 | v0.3.0 | 🔧 Complete all 22 tools (currently 11), full CLI subcommands, slash command enhancements, Agent tool | +3 weeks | | Phase 3 | v0.4.0 | 🌐 AWS Bedrock & GCP Vertex providers, MCP WebSocket transport, plugin system, feature flags | +4 weeks | | Phase 4 | v0.5.0 | 🚀 LSP integration, Remote/Server mode, Voice input, Vim mode, Extended Thinking, Cost Tracker | +4 weeks | | Phase 5 | v1.0.0 | 🎯 Performance tuning, security audit, full documentation, multi-platform release | +2 weeks |

Current Status

Completion: ████████████░░░░░░░░ 65%

✅ Done: Core engine, TUI, API client (Direct + OpenAI), context compaction,
         OAuth, session persistence, 11 tools, 14 slash commands
⚠️  WIP:  Bedrock/Vertex providers, MCP WebSocket, remaining tools & commands
❌ Todo: Permission wiring, Hook wiring, LSP, plugin system, Remote mode

📋 See the [full Roadmap](docs/ROADMAP.md) for detailed task breakdowns, architecture diagrams, and completion criteria.

Contributing

We welcome contributions! Please read [CONTRIBUTING.md](CONTRIBUTING.md) before submitting a pull request.

Quick checklist:

• Fork the repo and create a feature branch
• Make sure make test and make vet pass
• Write tests for new functionality
• Follow existing code style (run gofmt ./...)
• Open a pull request using the provided template

Security

To report a security vulnerability, please see [SECURITY.md](SECURITY.md). Do not open a public GitHub issue for security bugs.

License

This project is licensed under the MIT License — see [LICENSE](LICENSE) for details.

Related projects

• claude-code — the original TypeScript CLI
• anthropic-sdk-go — official Go SDK for the Anthropic API
• Model Context Protocol — open standard for connecting AI to tools

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: tunsuy
• Source: tunsuy/claude-code-go
• License: MIT

Install and usage instructions live in the source repository linked above.