Webhooks

Polling a list every minute to notice a new invoice is wasteful and slow. A webhook tells you instead.

Setting one up

1. Go to Settings → API keys & webhooks and open the Webhooks tab.
2. Add the URL we should post to. It must be HTTPS.
3. Choose the events you want.
4. Save. A secret is generated — you will use it to verify that a delivery came from us.
5. Use Test to send a sample delivery immediately.

What a delivery looks like

POST https://your-server.example/hooks/jai
Content-Type: application/json
X-JAI-Event: invoice.created
X-JAI-Signature: sha256=…

{
  "event": "invoice.created",
  "at": "2026-09-03T09:14:22.000Z",
  "data": { "id": "…", "number": "INV-2042", … }
}

Verifying it

Compute an HMAC-SHA256 of the raw request body using your endpoint’s secret and compare it with the signature header. Compare the two in constant time, and reject anything that does not match — an unverified webhook endpoint is an open door.

Answering

• Reply 2xx quickly. Do the work afterwards, not before replying.
• A non-2xx is retried; a slow endpoint will time out and be retried too.
• Deliveries can arrive more than once, so make your handler idempotent — key it on the event id.