If your harness lives inside the same sandbox as the user code, every credential the harness holds belongs to the user code too. The fix isn't a new protocol.…
An incident narrative about a 4-minute production outage caused by a JWKS rotation with insufficient overlap. The postmortem, the fix, and the CI check that catches it before deploy.
The eight checks every production JWT verifier must do, what each one prevents, and structured error codes for each failure mode. A reference doc for backend and identity teams.
Read any JWT's contents, understand every standard claim, and diagnose the most common auth errors — expired tokens, audience mismatches, wrong algorithms — from the decoded payload alone.
