What to check before you depend on a relay
A good AI API relay should behave like a clean transport layer: stable base URL, consistent request and response shapes, clear model naming, and error messages that help you debug quickly. For developers using Codex or other client libraries, the first pass is compatibility. The second pass is operations. Confirm that the relay handles streaming if you need it, preserves headers you rely on, and does not force unusual client changes. In a mixed environment, a relay that works as an OpenAI-compatible endpoint reduces integration time and keeps your code close to the official SDK patterns.
Cost structure matters too. 按量付费 can be easier to reason about than bundled plans when you are testing, prototyping, or running variable workloads. Look for transparent usage tracking, straightforward limits, and enough documentation to understand how tokens or requests are counted. If your team is using a Codex base_url override, make sure the relay is explicitly documented for that workflow and that the same settings work in local development, CI, and production.