What to compare before choosing
Start with compatibility. An AI API relay should accept the same request patterns your apps already use, especially if you rely on OpenAI SDKs or existing LangChain-style clients. Next, check model coverage. Some teams only need one fallback model; others want 多模型聚合 across chat, vision, and tool-calling endpoints. Billing matters too: 按量付费 is usually easier to forecast when traffic is irregular. Finally, evaluate latency, error handling, log visibility, and how clearly the service documents base URLs, headers, and rate limits.
For practical work, the best relay is the one that minimizes code changes, exposes consistent error messages, and keeps your staging tests close to production behavior.