91306: Sink endpoint returned a server error

Twilio records this error when Event Streams attempts to deliver an event, but the sink endpoint responds with an HTTP 5xx server error status code.

Because a 5xx error indicates a temporary processing failure on the destination server rather than a rejected payload, Twilio automatically retries event delivery according to the retry policy.

• Your receiving service encountered an unhandled exception or crash while processing the incoming payload (HTTP 500).
• A dependency required by your endpoint (such as a database, cache, or internal API) was unavailable or timing out.
• Your sink was overwhelmed by traffic or active connections.
• A load balancer or reverse proxy returned 502, 503, or 504 because no healthy backend was available.
• The request arrived during an active application deployment, restart, or rolling update.

• Check your target sink logs and error-tracking system around the failure timestamp to identify unhandled exceptions.
• Return an immediate HTTP 200 OK or 202 Accepted response upon receiving the payload, offloading heavy processing (like database writes) to a background worker queue.
• Verify that your load balancer, server health checks, and autoscaling policies are correctly configured to handle peak event volumes.
• Ensure your deployment strategy uses connection draining so in-flight requests from Twilio complete cleanly during code updates.

• 91300: Event delivery to sink failed
• 91305: Sink endpoint rejected the event
• 91308: Sink endpoint did not respond in time

• Event Streams overview
• Sink resource
• Subscription resource