Webhooks Troubleshooting
Solutions for deliveries not arriving, signature verification failing, and understanding retry behavior.
Deliveries Aren't Arriving
Check the endpoint is enabled — a disabled endpoint (toggle in Settings → Webhooks) receives nothing.
Confirm your plan — webhooks require Pro or above. If your plan was recently upgraded, refresh the Settings page.
Check the delivery log — click the history icon on the endpoint to see whether SMLLR is attempting delivery at all, and what status code your server returned.
Firewall/allowlist — if your server only accepts requests from known IPs, make sure it isn't silently dropping SMLLR's delivery attempts before they're logged as a failure on your end.
Signature Verification Is Failing
Use the raw body, not a re-parsed one — signing is computed over the exact bytes sent. If your framework parses JSON before you can access the raw string, the recomputed signature won't match.
Check the signed string format — it's
${timestamp}.${body}, with a literal period between the timestamp and the body, not the body alone.Confirm you're using the right secret — each endpoint has its own secret, shown once at creation. If you have multiple endpoints, mixing up secrets will always fail verification.
How Retries Work
A failed delivery (endpoint down, timeout, or a non-2xx response) retries automatically. After 5 total attempts, that specific delivery stops retrying and is recorded as permanently failed — it does not retry indefinitely. Each attempt (success or failure) is logged and visible in the delivery history for 90 days.
Still Having Issues?
If deliveries still aren't working after checking the above, email support@smllr.app with your endpoint URL and a screenshot of the delivery log. Our team will respond within 24 hours (Monday–Saturday).
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