How can I use webhooks with Letterhead?

Webhooks are automated messages — payloads — delivered to a unique URL whenever a specific event occurs in Letterhead. They’re generally faster and require less effort than polling for changes, and let you sync Letterhead data with other apps such as CMSes, CRMs, and team chat tools.

You can send the following events from Letterhead to another app via webhook:

1. Audience member created or updated
2. Newsletter published
3. Newsletter scheduled
4. Newsletter ready for metrics
5. Promotion campaign created
6. Promotion campaign details updated
7. Promotion campaign promotion changed
8. Promotion campaign status changed

“Newsletter ready for metrics” isn’t in the event dropdown yet when you create a webhook in the app (see below) — contact support if you’d like it enabled for your account in the meantime.

When should I use a webhook?

Use a webhook to trigger an action in another application based on an event in Letterhead. For example, when an audience member is created or updated, you might want them to receive a separate marketing email from your CRM — or you might notify an advertiser when the latest edition published with their ad. For a comparison with Zapier and the API, see How can Letterhead integrate with other software?.

How do I create a webhook?

Webhooks are managed at the organization level.

1. Log in and select your organization in the left-hand menu (the organization is the top option, above its channels).
2. On the organization page, open Settings, then select Webhooks.
3. Click Add new webhook.
4. In the slide-out, select the event you’d like to track.
5. Enter the endpoint (URL) — a secure URL where Letterhead will post the payload.
6. Turn on the Active toggle — it shows a checkmark when enabled.
7. Click Create. You’ll see a confirmation when the webhook is created successfully.

How can I remove a webhook?

You can deactivate or delete any webhook you create:

• Delete — hover over the webhook row and click the delete icon. This permanently deactivates and removes the webhook.
• Deactivate — click the Active toggle so the checkmark clears and the row is grayed out with an ‘x’. You can re-enable it later.

Need help?

Contact support if you run into trouble setting up an endpoint.