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

# Replay

> Re-send past events during incident recovery or after endpoint changes.

Sometimes your webhook endpoint missed events — deployment outage, certificate expiry, a bug that ate valid deliveries. Sly retains the last 30 days of events and lets you replay them.

## List past deliveries

```bash theme={null}
curl "https://api.getsly.ai/v1/webhooks/wh_.../deliveries?status=failed&since=2026-04-20" \
  -H "Authorization: Bearer pk_live_..."
```

Filters:

* `status` — `delivered`, `failed`, `pending`
* `event_type` — filter by type (`transfer.completed`, `approval.requested`, etc.)
* `since`, `until` — time window

Response:

```json theme={null}
{
  "data": [
    {
      "id": "del_...",
      "event_id": "evt_...",
      "event_type": "transfer.completed",
      "status": "failed",
      "attempts": 8,
      "last_attempt_at": "2026-04-21T09:22:00Z",
      "last_response_code": 500,
      "last_response_body": "Internal Server Error"
    }
  ],
  "pagination": { ... }
}
```

## Replay a single delivery

```bash theme={null}
curl -X POST https://api.getsly.ai/v1/webhooks/wh_.../deliveries/del_.../replay \
  -H "Authorization: Bearer pk_live_..."
```

Re-sends the exact event to the webhook URL, with the same signature and headers. The replayed delivery gets a **new** `X-Sly-Delivery-Id` but the **same** `X-Sly-Event-Id` — so your idempotency logic on the receiving side works correctly.

## Bulk replay

```bash theme={null}
curl -X POST https://api.getsly.ai/v1/webhooks/wh_.../replay \
  -d '{
    "since": "2026-04-20T00:00:00Z",
    "until": "2026-04-21T00:00:00Z",
    "event_types": ["transfer.completed", "transfer.failed"],
    "only_failed": true
  }'
```

Schedules a replay batch; deliveries go out rate-limited at 10/sec to avoid overwhelming your endpoint.

## Replay to a different URL

Useful for testing a new endpoint version against real traffic:

```bash theme={null}
curl -X POST https://api.getsly.ai/v1/webhooks/wh_.../replay \
  -d '{
    "since": "2026-04-20T00:00:00Z",
    "override_url": "https://staging.example.com/webhooks/sly"
  }'
```

The override URL signature uses the **current** webhook's secret, not the staging endpoint's. Set up matching secrets to verify.

## Idempotency matters here

Replayed events carry the original `event_id`. If your handler is idempotent, replays are safe — a replayed `transfer.completed` for a transfer you already marked complete will be a no-op.

If your handler isn't idempotent, replay can re-trigger side effects (duplicate emails, duplicate ledger entries). Fix idempotency first; replay second.

## Auto-disable on persistent failure

If 10+ consecutive deliveries fail, Sly automatically:

1. Emits a `webhook.failing` event to any other active webhooks
2. Alerts the dashboard
3. After 1 hour of continued failures, pauses the subscription

Paused subscriptions accumulate events in the replay store. Fix the underlying issue, then bulk-replay to recover:

```bash theme={null}
# Re-enable
curl -X POST /v1/webhooks/wh_.../resume

# Replay missed events
curl -X POST /v1/webhooks/wh_.../replay -d '{ "since": "2026-04-20T00:00:00Z" }'
```