Meet Switchyard: A Rust Proxy That Routes and Translates LLM Traffic Across OpenAI and Anthropic APIs

Switchyard is a new open-source Rust-based proxy and library that enables developers to route and translate LLM API traffic between OpenAI and Anthropic's API formats without modifying application code. The tool acts as a middleware layer, accepting requests in one API schema and forwarding them — with on-the-fly format translation — to whichever backend is configured, enabling seamless model switching and multi-provider failover. For developers building production systems, Switchyard addresses a real pain point: vendor lock-in at the API schema level, where switching from GPT to Claude (or vice versa) currently requires code changes throughout the application. Being written in Rust, it targets low-latency, high-throughput production environments where a Python middleware would introduce unacceptable overhead. This is a practical piece of infrastructure for any team running multi-model architectures or wanting provider redundancy without maintaining separate integration codebases.