I’m building OpenRain, an OpenAI-compatible AI API gateway. I originally thought the hard part would be integrating more providers. I was wrong. The hard part is absorbing inconsistency — and still giving developers something stable enough to trust in production.
Building an OpenAI-Compatible Multi-Model Gateway Taught Me What “Unified API” Really Means
When I first started thinking about a multi-model gateway, I had a fairly simple mental model.
Take a few major model providers. Put a clean API in front of them. Normalize the request shape. Forward the response. Add billing and routing. Done.
That picture survives for about five minutes.
