Trigger - Resend

A trigger is the first step in every Automation. It defines which event will start the Automation when received. When your application sends an event to Resend, every active Automation with a matching trigger will execute its workflow for that contact.

How it works

Using the dashboard
Using the API

The trigger is the first node in the editor.

Choose an existing custom event or type a new event name.

When creating an Automation via the API, the trigger is defined as the first item in the steps array with type: 'trigger'.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.automations.create({
  name: 'Welcome series',
  steps: [
    {
      key: 'start',
      type: 'trigger',
      config: { eventName: 'user.created' },
    },
  ],
  connections: [],
});

Event names cannot start with the resend: prefix, which is reserved for system events.

Identifying contacts

When sending an event to trigger an Automation, you must identify the contact using either a contact_id or an email address.

Using contact ID
Using email address

Use a contact ID when you already have the contact stored in your Audience:

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.events.send({
  event: 'user.created',
  contactId: '26e2b838-bf6d-4515-b6a7-17525b12b05a',
  payload: {
    plan: 'pro',
  },
});

Use an email address to trigger the Automation. If no contact with the provided email exists in your Audience, Resend will automatically create one when the run starts.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.events.send({
  event: 'user.created',
  email: 'user@example.com',
  payload: {
    plan: 'pro',
  },
});

Event payload

You can include a payload object with your event to pass data into the Automation. This data becomes available as variables in subsequent steps in the Automation using the event.* namespace.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.events.send({
  event: 'payment.failed',
  contactId: 'e169aa45-1ecf-4183-9955-b1499d5701d3',
  payload: {
    amount: 49.99,
    currency: 'USD',
    retryDate: '2026-11-01',
  },
});

In this example, you can use event.amount, event.currency, and event.retryDate in other automation conditions and steps, or in email templates. View the Send Event API reference for the full endpoint specification.

Configuration

config.event_name

string

required

The name of the event that triggers the automation.

{
  "key": "start",
  "type": "trigger",
  "config": {
    "event_name": "user.created"
  }
}

​How it works

​Identifying contacts

​Event payload

​Configuration

How it works

Identifying contacts

Event payload

Configuration