Claude Code Gemini API Proxy 🚀

Warning

🚨 Disclaimer: This project is an unofficial proxy tool intended strictly for educational and personal use. It is not affiliated with Google or Anthropic. Using this tool may violate their Terms of Service and could result in your account being banned. Use at your own risk.

Unlock free, unlimited usage of Claude Code CLI using Google's Gemini 3 models.

This proxy bridges the Claude Code CLI to Google's Cloud Code API. It allows you to use the latest, most advanced Claude model names (including 4.6 and 3.7) while routing them to Gemini 3 Pro (High Reasoning) and Gemini 3 Flash for free execution.

✨ Key Features

🧠 Advanced Model Support (Future-Proof)

Supports the absolute latest "Thinking" model definitions by mapping them to Gemini 3 Pro High Reasoning:

• Claude 4.6 Opus (claude-opus-4-6)
• Claude 3.7 Sonnet (claude-thinking-3-7)
• Gemini 3 Pro (gemini-3-pro)

🔄 Smart Fallback & Reliability

• Auto-Switching: If Gemini 3 Pro hits a rate limit (429), the proxy automatically retries the request using Gemini 3 Flash.
• No Interruptions: You never get stuck with "Overloaded" errors; the work continues seamlessly.

🛠️ Enhanced Tool Use

• Thought Signatures: Includes proprietary handling for Gemini's thought_signature, ensuring complex tool-use chains working perfectly where other proxies fail.
• Streaming: Full real-time streaming support.

📦 Installation

1. Clone Repository

git clone https://github.com/SovranAMR/claude-code-gemini-api.git
cd claude-code-gemini-api

2. Authenticate

You need to be logged in to Google Cloud. If you have gcloud installed:

gcloud auth application-default login

Alternatively, place your valid application_default_credentials.json at ~/.claude-code-google-credentials.json.

3. Install Claude Code

If you haven't already:

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

🚀 Usage

Simply run the start script. It handles everything:

bash start.sh

What it does:

1. Starts Proxy: Launches the local bridge on port 51200.
2. Configures CLI: Points Claude Code to http://localhost:51200.
3. Launches Interface: Starts Claude Code with Gemini 3 Pro (emulating Claude 4.6 capabilities) selected.

⚙️ Configuration

You can request different models in Claude Code, and they will be mapped automatically:

Claude Model Name Requested	Mapped To (Google)	Description
claude-opus-4-6-thinking	Gemini 3 Pro	High Reasoning / Thinking Mode
claude-sonnet-3-7	Gemini 3 Pro	Fast / Balanced
claude-3-5-haiku	Gemini 3 Flash	Ultra-Fast / Fallback

🤝 Contributing

Contributions are welcome! Please submit a Pull Request.

📄 License

MIT License. See LICENSE for details.