Resend events: contact.created, updated, deleted, sync your lists

TL;DR

These events fire whenever a contact was successfully created, updated, or deleted. On contact.created / contact.updated: sync the contact to your CRM or user store.

Steps

1. On contact.created / contact.updated: sync the contact to your CRM or user store. This is the hook for welcome sequences and profile updates.
2. On contact.deleted: honor the deletion everywhere, including backups and analytics stores, per your data-retention policy. A contact delete is often a privacy request.
3. Return 200 fast and process asynchronously like any other webhook.
4. Relying on contact.created to observe bulk imports. Resend's docs say it plainly: when importing multiple contacts using CSV, these events will not be triggered. If your pipeline depends on the webhook, bulk imports silently bypass it and your downstream systems drift. For imports, poll the contacts API or run a post-import reconciliation job instead.

When to use

You are seeing this: Return 200 fast and process asynchronously like any other webhook. Use this skill when you run into "Resend events: contact.created, updated, deleted, sync your lists".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Resend's event reference says contact.created, contact.updated, and contact.deleted occur whenever a contact was successfully created, updated, or deleted, and notes that importing multiple contacts using CSV will not trigger these events. Verified live at https://resend.com/docs/webhooks/event-types.