Webhooks

Billing happens while nobody is looking. A period opens at midnight, a collection confirms three blocks later, a retry succeeds on day six. Webhooks are how your application hears about all of it without polling.

An event delivered three times, failing twice with 502 and succeeding with 200 on the third attempt. — Delivery is retried until your endpoint answers

Setting up an endpoint

Create one in the dashboard under Developers, then Webhooks, or through the API:

curl -X POST "https://api.reclack.com/v1/webhooks" \
  -H "Api-Key: $RECLACK_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://acme.dev/hooks/reclack",
    "event_types": ["subscription.renewed", "invoice.paid", "payment.failed"]
  }'

The response includes a signing secret, shown once. Store it where your service can read it and nowhere else.

{
  "data": {
    "id": "whe_7Fh2PqX9",
    "url": "https://acme.dev/hooks/reclack",
    "status": "active",
    "secret": "whsec_9f1c4a2b8e7d0356",
    "event_types": ["subscription.renewed", "invoice.paid", "payment.failed"]
  }
}

The secret is shown once, at creation. If you lose it, roll it with POST /v1/webhooks/{id}/secret and update your service.

What a delivery looks like

POST /hooks/reclack HTTP/1.1
Host: acme.dev
Content-Type: application/json
Reclack-Event: evt_4Kd9ZmPq
Reclack-Signature: t=1792447200,v1=5d41402abc4b2a76b9719d911017c592

{
  "id": "evt_4Kd9ZmPq",
  "type": "subscription.renewed",
  "created_at": "2026-10-18T22:07:41Z",
  "data": {
    "id": "sub_4Kd9",
    "customer_id": "cus_7Fh2PqX9",
    "amount": "29.00",
    "currency": "USDC",
    "network": "base",
    "next_charge_at": "2026-11-18T22:07:41Z"
  }
}

Header	Carries
`Reclack-Signature`	A timestamp and an HMAC over the body. See Verifying.
`Reclack-Event`	The event id, so you can deduplicate without parsing the body.

Responding

Return 2xx quickly. Anything else counts as a failure and the delivery is retried.

app.post("/hooks/reclack", async (req, res) => {
  // Verify first, acknowledge second, work third.
  if (!verify(req)) return res.status(400).end();

  await queue.push(req.body);   // do the slow part elsewhere
  res.status(200).end();        // acknowledge within a few seconds
});

Acknowledge before you do the work. A handler that provisions an account, sends an email and writes to three tables before replying is a handler that will time out and receive the same event again.

Retries

Behaviour	Detail
Attempts	Up to six, spaced out rather than immediate
Counts as failure	Any non-`2xx`, a timeout, or a connection error
Response bodies	Captured and kept, so you can see what your endpoint said
After repeated failures	The endpoint pauses, and the dashboard says so

A paused endpoint is not a deleted one. Fix the handler, resume it, and replay the deliveries you missed.

Replaying

Every delivery is visible in the dashboard with its request, its response and its timing. Replay one from there, or through the API:

curl -X POST "https://api.reclack.com/v1/webhook-deliveries/whd_8Qd3/retry" \
  -H "Api-Key: $RECLACK_KEY"

A bad deploy should not cost you a day of events.

Before your endpoint exists

The events are stored either way. List them while you are still building:

curl "https://api.reclack.com/v1/events?limit=20" \
  -H "Api-Key: $RECLACK_KEY"

Get started

Core objects

Taking payments

Recurring billing

Money and events

Setting up an endpoint

What a delivery looks like

Responding

Retries

Replaying

Before your endpoint exists

​Setting up an endpoint

​What a delivery looks like

​Responding

​Retries

​Replaying

​Before your endpoint exists

Setting up an endpoint

What a delivery looks like

Responding

Retries

Replaying

Before your endpoint exists