Use Anthropic clients (like Claude Code) with Gemini or OpenAI backends. 🤝

A proxy server that lets you use Anthropic clients with Gemini or OpenAI models via LiteLLM. 🌉

• OpenAI API key 🔑
• Google AI Studio (Gemini) API key (if using Google provider) 🔑
• uv installed.

1. Clone this repository:

   git clone https://github.com/1rgs/claude-code-openai.git
   cd claude-code-openai

2. Install uv (if you haven't already):

   curl -LsSf https://astral.sh/uv/install.sh | sh

   (uv will handle dependencies based on pyproject.toml when you run the server)

3. Configure Environment Variables: Copy the example environment file:

   cp .env.example .env

   Edit .env and fill in your API keys and model configurations:

   • ANTHROPIC_API_KEY: (Optional) Needed only if proxying to Anthropic models.
   • OPENAI_API_KEY: Your OpenAI API key (Required if using the default OpenAI preference or as fallback).
   • GEMINI_API_KEY: Your Google AI Studio (Gemini) API key (Required if PREFERRED_PROVIDER=google).
   • PREFERRED_PROVIDER (Optional): Set to openai (default) or google. This determines the primary backend for mapping haiku/sonnet.
   • BIG_MODEL (Optional): The model to map sonnet requests to. Defaults to gpt-4.1 (if PREFERRED_PROVIDER=openai) or gemini-2.5-pro-preview-03-25.
   • SMALL_MODEL (Optional): The model to map haiku requests to. Defaults to gpt-4.1-mini (if PREFERRED_PROVIDER=openai) or gemini-2.0-flash.

   Mapping Logic:

   • If PREFERRED_PROVIDER=openai (default), haiku/sonnet map to SMALL_MODEL/BIG_MODEL prefixed with openai/.
   • If PREFERRED_PROVIDER=google, haiku/sonnet map to SMALL_MODEL/BIG_MODEL prefixed with gemini/ if those models are in the server's known GEMINI_MODELS list (otherwise falls back to OpenAI mapping).

4. Run the server:

   uv run uvicorn server:app --host 0.0.0.0 --port 8082 --reload

   (--reload is optional, for development)

1. Install Claude Code (if you haven't already):

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

2. Connect to your proxy:

   ANTHROPIC_BASE_URL=http://localhost:8082 claude

3. That's it! Your Claude Code client will now use the configured backend models (defaulting to Gemini) through the proxy. 🎯

The proxy automatically maps Claude models to either OpenAI or Gemini models based on the configured model:

The following OpenAI models are supported with automatic openai/ prefix handling:

• o3-mini
• o1
• o1-mini
• o1-pro
• gpt-4.5-preview
• gpt-4o
• gpt-4o-audio-preview
• chatgpt-4o-latest
• gpt-4o-mini
• gpt-4o-mini-audio-preview
• gpt-4.1
• gpt-4.1-mini

The following Gemini models are supported with automatic gemini/ prefix handling:

• gemini-2.5-pro-preview-03-25
• gemini-2.0-flash

The proxy automatically adds the appropriate prefix to model names:

• OpenAI models get the openai/ prefix
• Gemini models get the gemini/ prefix
• The BIG_MODEL and SMALL_MODEL will get the appropriate prefix based on whether they're in the OpenAI or Gemini model lists

For example:

• gpt-4o becomes openai/gpt-4o
• gemini-2.5-pro-preview-03-25 becomes gemini/gemini-2.5-pro-preview-03-25
• When BIG_MODEL is set to a Gemini model, Claude Sonnet will map to gemini/[model-name]

Control the mapping using environment variables in your .env file or directly:

Example 1: Default (Use OpenAI) No changes needed in .env beyond API keys, or ensure:

OPENAI_API_KEY="your-openai-key"
GEMINI_API_KEY="your-google-key" # Needed if PREFERRED_PROVIDER=google
# PREFERRED_PROVIDER="openai" # Optional, it's the default
# BIG_MODEL="gpt-4.1" # Optional, it's the default
# SMALL_MODEL="gpt-4.1-mini" # Optional, it's the default

Example 2: Prefer Google

GEMINI_API_KEY="your-google-key"
OPENAI_API_KEY="your-openai-key" # Needed for fallback
PREFERRED_PROVIDER="google"
# BIG_MODEL="gemini-2.5-pro-preview-03-25" # Optional, it's the default for Google pref
# SMALL_MODEL="gemini-2.0-flash" # Optional, it's the default for Google pref

Example 3: Use Specific OpenAI Models

OPENAI_API_KEY="your-openai-key"
GEMINI_API_KEY="your-google-key"
PREFERRED_PROVIDER="openai"
BIG_MODEL="gpt-4o" # Example specific model
SMALL_MODEL="gpt-4o-mini" # Example specific model

This proxy works by:

1. Receiving requests in Anthropic's API format 📥
2. Translating the requests to OpenAI format via LiteLLM 🔄
3. Sending the translated request to OpenAI 📤
4. Converting the response back to Anthropic format 🔄
5. Returning the formatted response to the client ✅

The proxy handles both streaming and non-streaming responses, maintaining compatibility with all Claude clients. 🌊

Contributions are welcome! Please feel free to submit a Pull Request. 🎁

本代理支持多渠道API路由，可通过模型名后缀 :渠道名 灵活指定不同API端点和KEY，适用于多供应商/多账号/多代理等场景。

在 .env 文件中添加如下内容：

# 默认渠道配置（向后兼容）
BASE_URL="https://gemini-balance.eqing.tech/openai/v1"
API_KEY="sk-UIpCcB7ic4xxxxxx8F5C68744"
GEMINI_API_KEY="sk-gemini-default"
OPENAI_API_KEY="sk-openai-default"
ANTHROPIC_API_KEY="sk-anthropic-default"

# 新增自定义渠道
CHANNEL_GEMINI2_BASE_URL="https://another-gemini-api.com/v1"
CHANNEL_GEMINI2_API_KEY="sk-gemini2-key"

CHANNEL_CLAUDE2_BASE_URL="https://another-claude-api.com/v1"
CHANNEL_CLAUDE2_API_KEY="sk-claude2-key"

# 其他配置保持不变
PREFERRED_PROVIDER="openai"
BIG_MODEL="openai/gemini-2.5-pro-cfp"
SMALL_MODEL="openai/gemini-2.5-flash"
DEBUG="true"

• CHANNEL_<NAME>_BASE_URL 和 CHANNEL_<NAME>_API_KEY 用于定义新渠道。
• <NAME> 不区分大小写，调用时统一小写。

• 默认行为（不带渠道后缀）：

  { "model": "gemini/gemini-2.5-pro", ... }

  使用 BASE_URL 和 API_KEY（或各自模型类型的 KEY）。

• 指定渠道（推荐）：

  { "model": "gemini/gemini-2.5-pro:gemini2", ... }
  { "model": "anthropic/claude-3-opus:claude2", ... }

  路由到对应的 CHANNEL_GEMINI2_BASE_URL/CHANNEL_GEMINI2_API_KEY 或 CHANNEL_CLAUDE2_BASE_URL/CHANNEL_CLAUDE2_API_KEY。

# 默认渠道
curl -X POST http://localhost:8082/v1/messages \
  -H "Content-Type: application/json" \
  -d '{ "model": "gemini/gemini-2.5-pro", "max_tokens": 1000, "messages": [{"role": "user", "content": "Hello"}] }'

# 指定 gemini2 渠道
curl -X POST http://localhost:8082/v1/messages \
  -H "Content-Type: application/json" \
  -d '{ "model": "gemini/gemini-2.5-pro:gemini2", "max_tokens": 1000, "messages": [{"role": "user", "content": "Hello"}] }'

# 指定 claude2 渠道
curl -X POST http://localhost:8082/v1/messages \
  -H "Content-Type: application/json" \
  -d '{ "model": "anthropic/claude-3-opus:claude2", "max_tokens": 1000, "messages": [{"role": "user", "content": "Hello"}] }'

1. 完全兼容 litellm 前缀：如 gemini/、openai/、anthropic/，不影响格式识别。
2. 灵活路由：通过 :渠道名 后缀，任意模型可路由到不同API端点和KEY。
3. 向后兼容：不指定渠道时，行为与原有一致。
4. 多账号/多代理支持：适合企业、团队、个人多API管理。
5. 配置简单：仅需在 .env 文件中增加渠道配置。

⚠️ 注意：渠道名统一小写，调用时如 :gemini2、:claude2。