Since the June fork changelog, this fork added several subscription-backed providers and fixed prompt-caching reliability across the transformer stack. Exact introduction dates from the git history:
This fork of claude-code-router adds several provider integrations, UI improvements, and infrastructure changes. Here's the timeline of what was added and when.
Starting from version 4.5, GLM has supported Claude Code. I've been following its progress closely, and many users have reported that reasoning could not be enabled within Claude Code. Recently, thanks to sponsorship from Zhipu, I decided to investigate this issue in depth. According to the official documentation, the/chat/completions endpoint has reasoning enabled by default, but the model itself decides whether to think:
Since the release of claude-code-router, I've received a lot of user feedback, and quite a few issues are still open. Most of them are related to support for different providers and the lack of tool usage from the deepseek model.
Originally, I created this project for personal use, mainly to access claude code at a lower cost. So, multi-provider support wasn't part of the initial design. But during troubleshooting, I discovered that even though most providers claim to be compatible with the OpenAI-style /chat/completions interface, there are many subtle differences. For example:
When Gemini's tool parameter type is string, the format field only supports date and date-time, and there's no tool call ID.
OpenRouter requires cache_control for caching.
The official DeepSeek API has a max_output of 8192, but Volcano Engine's limit is even higher.
Aside from these, smaller providers often have quirks in their parameter handling. So I decided to create a new project, musistudio/llms, to deal with these compatibility issues. It uses the OpenAI format as a base and introduces a generic Transformer interface for transforming both requests and responses.
Once a Transformer is implemented for each provider, it becomes possible to mix-and-match requests between them. For example, I implemented bidirectional conversion between Anthropic and OpenAI formats in AnthropicTransformer, which listens to the /v1/messages endpoint. Similarly, GeminiTransformer handles Gemini <-> OpenAI format conversions and listens to /v1beta/models/:modelAndAction.
When both requests and responses are transformed into a common format, they can interoperate seamlessly:
As early as the day after Claude Code was released (2025-02-25), I began and completed a reverse engineering attempt of the project. At that time, using Claude Code required registering for an Anthropic account, applying for a waitlist, and waiting for approval. However, due to well-known reasons, Anthropic blocks users from mainland China, making it impossible for me to use the service through normal means. Based on known information, I discovered the following:
console.log usage, launching with --inspect to hook into Chrome DevTools, or even debugging obfuscated code using d8.My goal was to use Claude Code without an Anthropic account. I didn't need the full source code—just a way to intercept and reroute requests made by Claude Code to Anthropic's models to my own custom endpoint. So I started the reverse engineering process: