Webhook 401 Unauthorized: fixing authentication failures

A 401 Unauthorized status means your endpoint rejected the webhook delivery because an authentication check failed before your handler could process the event.

Why webhook endpoints return 401

• Global authentication middleware: A common oversight is mounting user session or JWT middleware globally across all routes. Webhook endpoints must be explicitly exempted from user-session checks.
• Stale or rotated API keys: If your webhook receiver expects a pre-shared token in the Authorization: Bearer ... header, verify that the token configured in the provider dashboard matches your environment variables.
• Signature verification returning 401 instead of 400: While signature mismatches are strictly bad requests (`400`), some libraries throw unauthorized exceptions that default to 401. See signature mismatch troubleshooting.

Fixing the issue

Ensure your web framework excludes public webhook routes (e.g. /api/webhooks/*) from CSRF protection and standard session cookie middleware. Security for webhooks should rely on cryptographic HMAC signatures rather than user cookies.