n8n Webhook Incident Triage
Separate ingress, workflow execution, credentials, downstream API and response-contract failures in a self-hosted n8n webhook.
Evidence tier describes my hands-on relationship with the content. Official sources describe platform contracts/documentation. Production observations should not automatically be treated as official limits.
Prove ingress
Confirm DNS/TLS/reverse proxy reach the expected n8n webhook path before debugging workflow nodes.
Check execution history
Find whether the request created an execution and capture the first node that failed.
Validate input contract
Check required fields, content type, signature/auth and payload size before side effects.
Validate credential scope
Distinguish invalid/expired credentials from a correct credential lacking downstream permission.
Inspect retries and idempotency
Make sure a caller retry cannot duplicate emails, writes, events or other irreversible effects.
Return a stable response
Public callers should receive an intentional status/body instead of an internal stack trace.
Capture the regression case
Turn the incident into a test payload, Production Bite or checklist item.