ChatGPT Claude Gemini API Key Errors and Access Restrictions Troubleshooting Checklist

If your backend integrates the ChatGPT, Claude, and Gemini APIs, the most common failure isn’t that the models are bad—it’s API key errors, network connectivity issues, or region-policy blocks. Midjourney doesn’t use the API-key system, but in Discord you’ll still run into permission and quota prompts—same thing at its core: you’re not “allowed.”

1-minute self-check: 90% of API errors are here

• Wrong key pasted: extra spaces or line breaks were copied, or you used a “project key” as a “personal key”
• Insufficient key permissions: billing not enabled / no card linked / your organization or project hasn’t been authorized for the corresponding model
• Environment variables not taking effect: did you restart the service? are the container and the host machine using two different configs?
• Proxy issues: being able to open webpages doesn’t mean your backend can directly reach the API domain—many people get stuck here

Treat the cause based on the error message

Shows Unauthorized or Invalid API key

Don’t rush to blame the platform. First regenerate the key in the console and revoke the old one; then check whether you’re using the correct field in the request headers. When building bots or plugins, some Koishi plugins often throw errors due to the key field name or paste format.

Shows Rate limit or Quota exceeded

This isn’t “broken”—you’re just using it too aggressively. Reduce concurrency and add retries with backoff; if you need stability, move to a plan with a higher quota. Same with Midjourney when fast hours run out—switch to slow queueing and don’t get worked up.

Shows Network error or Access restricted

Use curl on the backend server to test direct connectivity to the target domain. If your company network or data center’s international routing is unstable, switching routes is often more effective than switching models. Claude and Gemini are more sensitive to region and risk controls, and a messy network environment can easily trigger them.

An easier approach

If you only want it to “just work,” stop trial-and-error on payments, regions, and routes. You can go to Titikey for a more hassle-free way to get set up and use it, and save your time for real creation and product work.