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

# Webhook overview

> Receive matches and monitoring changes as signed POST requests.

LeadFast sends a signed POST when a relevant public Reddit post matches your product. Delivery is at least once.

<Note>
  The setup prompt below is the whole integration. Paste it into your coding agent and it will build and test the endpoint with you.
</Note>

<Snippet file="webhook-setup-prompt.mdx" />

## Endpoint requirements

* One public HTTPS URL on port 443.
* Respond with any 2xx status within 10 seconds.
* Redirects are not followed.
* The same body and `LeadFast-Delivery` value may arrive more than once: deduplicate.

## Headers

| Header | Value |
| - | - |
| `LeadFast-Event` | `webhook.test`, `reddit.post.matched`, or `product.understanding.updated` |
| `LeadFast-Delivery` | Stable UUID for deduplicating retries |
| `LeadFast-Signature` | `t=UNIX_SECONDS,v1=HEX_HMAC` |

## Request shape

```bash theme={null}
curl --request POST 'https://your-domain.example/leadfast' \
  --header 'Content-Type: application/json' \
  --header 'LeadFast-Event: webhook.test' \
  --header 'LeadFast-Delivery: 00000000-0000-4000-8000-000000000000' \
  --header 'LeadFast-Signature: t=TIMESTAMP,v1=HMAC_SHA256' \
  --data '{"event":"webhook.test","version":1,"test":true,"sent_at":"2026-08-29T18:03:00.000Z"}'
```

Send a real test from the app before relying on an endpoint: a destination is only active after a successful test.

<CardGroup cols={2}>
  <Card title="Verify signatures" icon="shield-check" href="/webhooks/signature">
    HMAC-SHA256, raw bytes and the five-minute window.
  </Card>

  <Card title="Event payloads" icon="brackets-curly" href="/webhooks/events">
    Every field of every event.
  </Card>
</CardGroup>


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