How to test an OpenAI-compatible AI API gateway without rewriting your app

A practical staging checklist for teams that want multi-model access, better cost control, and fewer provider-specific rewrites. Most teams do not start with a model-routing strategy. They start with one provider, one API key, and one feature that finally works. That is fine for a prototype. The problem usually appears after the feature becomes useful: usage grows faster than expected; one model is too expensive for routine tasks; a second model performs better for translation or summaries;...