CustomRouter lets you combine multiple LLMs into one OpenAI-compatible endpoint where you control the routing logic. Write rules in plain English — "use strong models for complex reasoning, fast cheap models for simple tasks" — and the CustomRouter chooses the right model. Supports most providers OpenRouter, Vercel Gateway etc. includes thread pinning and ready-made presets to start from. Open source (AGPL-3.0), self-hostable on Cloudflare, BYOK. Free tier available.