401 — the server doesn't know who you are
What is this error?
You are not authenticated. Either no credentials were sent, or the ones sent are expired or invalid.
Common Causes
- The session expired and was never refreshed.
- The token isn't being attached to the request.
- You're using the wrong API key, or a key from another project.
- The user genuinely is signed out.
How to fix it (Check First)
- 1Network tab → request headers → is an Authorization header present?
- 2Sign out and back in. Does it work for one request and then fail?
- 3Confirm the key belongs to the same project as the URL.
What NOT to do
- Do not switch to an admin/service key in the browser to get past it. That is a breach, not a fix.
Technical Details
401 means missing or invalid authentication. Compare with 403, which means you were identified successfully but are not permitted.