> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prudra.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Retry behaviour

> Exponential backoff schedule, dead-letter queue, and manual replay for failed webhook deliveries.

## Retry behaviour

Prudra retries webhook deliveries up to 5 times with exponential backoff. After 5 failures, the delivery moves to the dead-letter queue where you can replay it manually.

## Retry schedule

| Attempt             | Delay after previous failure |
| ------------------- | ---------------------------- |
| Attempt 1 (initial) | Immediate                    |
| Retry 1             | 5 seconds                    |
| Retry 2             | 10 seconds                   |
| Retry 3             | 20 seconds                   |
| Retry 4             | 40 seconds                   |
| Retry 5             | 80 seconds                   |
| Dead-letter         | After retry 5 failure        |

Total time from first attempt to dead-letter: \~2.5 minutes.

## What counts as a failure

Prudra considers a delivery failed if:

* Your endpoint returns any non-2xx status code
* Your endpoint does not respond within 10 seconds
* The TCP connection is refused

Returning 200 immediately (before processing) and processing asynchronously is the correct pattern.

## Respond 200 before processing

```typescript theme={null}
app.post('/webhooks/prudra', express.raw({ type: '*/*' }), async (req, res) => {
  // Respond 200 immediately — Prudra won't retry
  res.sendStatus(200);

  // Verify and process asynchronously
  const isValid = verifyWebhook({ ... });
  if (!isValid) return;

  const event = JSON.parse(req.body.toString());
  await processEventAsync(event);  // slow processing is safe here
});
```

If you respond 200 only after your processing is complete, slow handlers will cause retries when they exceed the 10-second timeout.

## Manual replay

View and replay failed deliveries from the API:

```bash theme={null}
# List delivery attempts for a webhook
curl "https://api.prudra.dev/webhooks/wh_clx1abc123/attempts" \
  -H "Authorization: Bearer prv_test_sk_..."

# Replay a specific delivery
curl -X POST https://api.prudra.dev/webhooks/wh_clx1abc123/replay \
  -H "Authorization: Bearer prv_test_sk_..." \
  -H "Content-Type: application/json" \
  -d '{ "deliveryId": "del_clx1abc123" }'
```

## Idempotency

Your webhook handler must be idempotent. Retries deliver the same `eventId` — check whether you've already processed an event before acting:

```typescript theme={null}
const event = JSON.parse(req.body.toString());

// Idempotency check
const already = await db.webhookEvents.findOne({ eventId: event.eventId });
if (already) return;  // already processed

await db.webhookEvents.create({ eventId: event.eventId });
await processEvent(event);
```

## Related

* [Register a webhook](/webhooks/register) — set up webhook endpoints
* [Verify signatures](/webhooks/verify-signatures) — validate delivery authenticity
* [Event reference](/webhooks/event-reference) — all event types and payloads