How to sanity-check an OpenAI-compatible API relay before wiring it into production

OpenAI-compatible API relays and model aggregators are convenient: you can often change base_url, keep most SDK code the same, and test multiple model providers behind one interface. But before a relay endpoint becomes part of a real product, price is only one part of the decision. The expensive failures usually come from availability, latency, streaming behavior, token accounting, model mismatch, and unclear security boundaries. Here is a practical checklist I use before trusting a new endpoint. 1.