twenty/packages/twenty-apps/internal/twenty-for-twenty

This is a Twenty application bootstrapped with create-twenty-app.

Overview

Twenty for Twenty is the official internal Twenty app. It is organized into modules, each integrating a third-party service with Twenty.

Resend module (src/modules/resend/)

Two-way sync between Twenty and the Resend email platform. The module syncs contacts, segments, templates, broadcasts, and emails.

Inbound (Resend -> Twenty):

• A cron job runs every 5 minutes to pull all entities from the Resend API
• A webhook endpoint receives real-time events for contacts and emails

Outbound (Twenty -> Resend):

• Database event triggers push contact and segment changes back to Resend when records are created, updated, or deleted in Twenty

Getting Started

1. Install and run the app

yarn twenty dev

This registers the app with your local Twenty instance at http://localhost:3000/settings/applications.

2. Configure app variables

In Twenty, go to Settings > Applications > Twenty for Twenty and set:

• RESEND_API_KEY -- Your Resend API key. Create one at https://resend.com/api-keys (full access recommended).
• RESEND_WEBHOOK_SECRET -- The signing secret for verifying inbound webhooks (see "Webhook setup" below).

3. Webhook setup

The app exposes an HTTP endpoint at /s/webhook/resend that receives Resend webhook events. To connect it:

1. Go to https://resend.com/webhooks
2. Click Add webhook
3. Set the Endpoint URL to your Twenty server's public URL + /s/webhook/resend (e.g. https://your-domain.com/s/webhook/resend)
4. Set Events types to All Events
5. Click Add
6. Copy the signing secret Resend displays and paste it into the RESEND_WEBHOOK_SECRET app variable in Twenty

The webhook handles:

• Contact events (contact.created, contact.updated, contact.deleted) -- upserts/deletes Resend contact records in Twenty
• Email events (email.sent, email.delivered, email.bounced, email.opened, email.clicked, etc.) -- updates delivery status on Resend email records in real-time
• Domain events -- logged and skipped (no domain object in the app yet)

4. Testing webhooks locally

Install the Resend CLI:

brew install resend/cli/resend

Or via npm if Homebrew has issues:

npm install -g resend-cli

Authenticate:

resend login

Start the webhook listener with forwarding to your local Twenty server:

resend webhooks listen --forward-to http://localhost:3000/s/webhook/resend

The CLI will:

1. Create a public tunnel automatically
2. Register a temporary webhook in Resend pointing to that tunnel
3. Forward incoming events (with Svix signature headers) to your local Twenty server
4. Display events in the terminal as they arrive
5. Clean up the temporary webhook when you press Ctrl+C

To trigger test events, create or update a contact in the Resend dashboard, or send a test email.

Sync behavior

Inbound sync

Source	Mechanism	Entities
Cron (every 5 min)	Polls Resend API, upserts into Twenty	Contacts, segments, templates, broadcasts, emails
Webhook (real-time)	Receives Resend events via HTTP	Contacts, emails

Outbound sync

Twenty action	Resend API call
Create contact	contacts.create() -- writes resendId back to Twenty
Update contact (name, email, unsubscribed)	contacts.update()
Delete contact	contacts.remove()
Create segment	segments.create() -- writes resendId back to Twenty
Delete segment	segments.remove()

Loop prevention

A lastSyncedFromResend field on contact, segment, and email records tracks when data came from Resend. Outbound triggers skip processing when this field is part of the update, preventing infinite echo loops between inbound and outbound sync.

Commands

Run yarn twenty help to list all available commands.

Learn More

• Twenty Apps documentation
• twenty-sdk CLI reference
• Resend API documentation
• Discord