Notification Webhooks

Get alerted the instant a webhook arrives — no need to watch the dashboard.

Add a notification URL to any endpoint and the receiver will POST a JSON summary after each captured request. Works with Slack incoming webhooks, Discord webhooks, Microsoft Teams connectors, or any service that accepts HTTP POST with a JSON body.

Setup

1. Open endpoint settings (gear icon in the dashboard URL bar)
2. In the Notification Webhook section, paste your notification URL
3. Click Save Changes

That's it. The next webhook that hits your endpoint will trigger a notification.

Payload format

The receiver sends a POST request with a JSON body:

{
  "slug": "my-endpoint",
  "method": "POST",
  "path": "/webhooks/stripe",
  "ip": "203.0.113.42",
  "receivedAt": "2026-04-03T12:34:56.789Z",
  "preview": "{\"type\":\"checkout.session.completed\",\"data\":{\"object\":{\"id\":\"cs_test..."
}

Rate limiting

Notifications are rate-limited to one per second per endpoint. If your endpoint receives a burst of webhooks, only the first notification fires — subsequent ones within the cooldown window are silently skipped. This prevents flooding your Slack channel during high-traffic periods.

Delivery behavior

• Fire-and-forget — notifications don't block the webhook response. The sender gets their response immediately regardless of notification delivery.
• No retries — if the notification URL is unreachable or returns an error, it's silently dropped. The captured request is unaffected.
• 5-second timeout — the receiver gives up after 5 seconds to avoid resource exhaustion.

Slack setup

1. In Slack, go to Your Apps and create an app (or use an existing one)
2. Enable Incoming Webhooks and click Add New Webhook to Workspace
3. Choose a channel and copy the webhook URL
4. Paste into your endpoint's notification URL field

Slack will display the JSON payload as a code block. For richer formatting, route through a small serverless function that transforms the payload into Slack Block Kit format.

Discord setup

1. In Discord, go to Server Settings > Integrations > Webhooks
2. Click New Webhook, choose a channel, and copy the webhook URL
3. Append /slack to the URL (Discord's Slack-compatible endpoint): https://discord.com/api/webhooks/.../slack
4. Paste into your endpoint's notification URL field

SDK and MCP

Set notificationUrl when creating or updating endpoints programmatically:

const client = new WebhooksCC({ apiKey: "whcc_..." });
 
// Set on creation
const endpoint = await client.endpoints.create({
  name: "my-endpoint",
  notificationUrl: "https://hooks.slack.com/services/T.../B.../xxx",
});
 
// Update later
await client.endpoints.update("my-endpoint", {
  notificationUrl: "https://discord.com/api/webhooks/.../slack",
});
 
// Clear it
await client.endpoints.update("my-endpoint", {
  notificationUrl: null,
});

The MCP server exposes notificationUrl on both create_endpoint and update_endpoint tools.

Clearing the notification URL

Set the field to empty in endpoint settings and save, or pass null via the SDK/API. The endpoint will stop sending notifications immediately.