FMProxy

FMProxy is a local OpenAI-compatible chat completions proxy for Apple Foundation Models on macOS 26 Tahoe. It requires macOS 26.0 or later, Xcode with the macOS 26 SDK, and Apple Foundation Models available on the Mac. The project can be built with xcodebuild or the provided build.sh script, and the standalone Apple Silicon binary can be started from the repository root. By default it listens on 127.0.0.1:8080, with command-line options for host, port, logging suppression, structured-output validation, and help. The server exposes GET /health, GET /v1/models, and POST /v1/chat/completions. The chat endpoint accepts system, user, and assistant roles; stream: false returns regular JSON, while stream: true sends OpenAI-compatible Server-Sent Events followed by data: [DONE]. Token statistics are returned as 0. Generations are processed one at a time in FIFO order, while health and model-list requests remain available. Structured output supports response_format values of json_object and json_schema, with optional full JSON Schema validation disabled by default. HTTP limits include headers up to 64 KiB, bodies up to 10 MiB, and a 30-second timeout for incomplete requests.