Testing

Hooks has no simulator. Messages sent with a sandbox (coss_test_…) key are delivered for real, so your test endpoint gets the same signed request, retries and attempts as a live one. What's different:

• Nothing is billed, however many messages you send.
• The limits are lower: 100 applications, 5 endpoints per application and 2,000 deliveries a day per environment (limits).
• The portal can be embedded from http://localhost while you develop.
• Failing endpoints don't count against your reputation.

The whole loop

Endpoints must be public https:// URLs, so use a tunnel or a request inspector to reach your machine: localhost and private addresses are refused. coss listen doesn't help here, since it forwards the environment's own webhooks, not Hooks deliveries.

coss hooks event-types create invoice.paid --example '{"invoice_id":"in_1","amount":4200}'
coss hooks apps create "Test customer" --uid test-customer
coss hooks endpoints add test-customer --url https://your-tunnel.example/hooks
coss hooks send test-customer invoice.paid
coss hooks deliveries test-customer
coss hooks attempts test-customer <delivery>

coss hooks endpoints add prints the endpoint's signing secret: give it to your receiver to verify requests. coss hooks attempts shows what each request got back, and coss hooks portal test-customer --open shows your customer's view of it all.

To try one endpoint without reaching the application's others, send it a test message, which is free in live environments too:

const { data: message } = await coss.hooks.endpoints.sendTest("test-customer", endpointId, {
  event_type: "invoice.paid",
});
// Without a `payload`, it uses the event type's first example.

Failures

Point an endpoint at a URL that answers 500 to watch the real retry schedule. coss hooks deliveries test-customer --status failed lists what gave up, and coss hooks retry test-customer <delivery> tries one again.

Waiting 5 days for an endpoint to be disabled isn't practical, so test your handler for that event with a sample, which goes to your own webhook endpoints and coss listen:

coss trigger hook_endpoint.disabled