Testing webhooks

You do not need a real event to try a receiver. The test method sends one event to one endpoint, through the same signing, retries and delivery log as any other event.

#Send the test event

sylphx events webhook-endpoints test orgs/acme/projects/shop/envs/production/webhook_endpoints/my-endpoint

The answer is the delivery that was queued for the endpoint.

#What your receiver gets

A CloudEvent of type sylphx.webhook.test:

{
  "specversion": "1.0",
  "id": "…",
  "source": "https://api.sylphx.com/events",
  "type": "sylphx.webhook.test",
  "subject": "orgs/acme/projects/shop/envs/production/webhook_endpoints/my-endpoint",
  "time": "2026-10-01T12:00:00Z",
  "datacontenttype": "application/json",
  "data": {
    "message": "A test event from Sylphx Events.",
    "webhook_endpoint": "orgs/acme/projects/shop/envs/production/webhook_endpoints/my-endpoint"
  }
}

It is signed with the endpoint's secret and carries the three Standard Webhooks headers, so a receiver that passes the test verifies real deliveries the same way.

#Read the delivery back

Read the delivery by its name until it lands. state becomes delivered once your receiver answered 2xx; dead_lettered means it did not, and the attempts record what your endpoint answered.

sylphx events webhook-deliveries get orgs/acme/projects/shop/envs/production/webhook_endpoints/my-endpoint/webhook_deliveries/<delivery>

A receiver that answers 4xx (other than 408, 425 and 429) or a redirect is dead-lettered at once; 408, 425, 429 and 5xx are retried on the schedule.

#When the receiver was down

Fix the receiver, then replay the endpoint for the time range it missed: every dead-lettered delivery created in that range is sent again, as a new attempt, up to 10,000 per replay.