You clearly copied the key, but as soon as you run it you get errors: Invalid API key, 401, 403, and even 429 rate limiting. I’ve fallen into this trap too—the most annoying part is that “everything looks fine.” Below I’ll troubleshoot based on the most common causes I’ve personally encountered, and I’ll also clarify the situation with Midjourney third-party APIs.
1. First, confirm you’re using the correct account and project
ChatGPT’s API is not the same as the web membership; with Claude and Gemini it’s also common that after “switching organizations/projects” the key can’t be read. The project where you generated the key in the console must match the project configured in your code.
2. Check whether your key contains extra spaces or line breaks
Many “API key errors” are actually caused by an extra space or newline added during copying. It’s recommended to paste the key into plain text and then copy it again—don’t copy it directly from a chat app.
3. Don’t get the header format wrong
The most classic failure point: the Authorization format is incorrect, or you typed Bearer as something else. Field names can also differ across platforms, so following the official examples is the safest. Some bot plugin docs even call out “API key errors” specifically—there’s a reason for that.
