Your AI Gateway's 200 OK Is Lying to You — A Practical Guide to Response Validation

Every AI gateway on the market — LiteLLM, Portkey, OpenRouter, Olla — checks the same things: HTTP status code, response time, token usage. If the backup provider returns HTTP 200 with valid JSON, the gateway declares success.

But HTTP 200 only tells you the request completed. It says nothing about whether the response is correct.

The Silent Failure Pattern

In production monitoring across multi-provider setups, a consistent pattern emerges during failover events:

Primary provider returns 5xx or times out