Claude to ChatGPT is an open-source adapter that converts Anthropic’s Claude API into the OpenAI Chat API format, so tools built for ChatGPT can talk to Claude unchanged. Hosted on GitHub with about 1,300 stars under the MIT license, it can be deployed on Cloudflare Workers or with Docker, with the last updates in 2024.
Many applications, SDKs and front-ends speak only the OpenAI chat completions format. This small proxy sits in front of the Claude API and translates requests and responses between the two formats: your client sends an OpenAI-style request, the adapter forwards it to Anthropic, and streams the answer back in OpenAI style. Streaming responses are supported, as are the Claude Instant and Claude 2 model generations it was built for. Deployment is deliberately lightweight โ a Cloudflare Worker needs no server at all, while a Docker image covers self-hosted setups โ making it a quick compatibility bridge when you want to evaluate or adopt Claude inside an existing OpenAI-shaped stack. Documentation is provided in English, Chinese and Japanese, and packaged releases on GitHub make it straightforward to get a worker or container running quickly.
Claude to ChatGPT is free and open source under the MIT license. Running it on Cloudflare Workers or your own Docker host costs nothing beyond your infrastructure; you only pay Anthropic for the Claude API usage itself, using your own API key.
Developers with OpenAI-based tooling who want to route requests to Claude models without rewriting client code, and teams prototyping multi-provider setups behind a single familiar API shape.