n8n Trigger Node Development

Build custom trigger nodes for n8n v1.x using event/timer, polling, or webhook patterns.

Quick Reference

Pattern	Method	Interface	Description Key	Use When
Event/Timer	`trigger()`	`ITriggerFunctions`	`group: ['trigger']`	Listening to events, cron schedules, streams
Polling	`poll()`	`IPollFunctions`	`polling: true`	Periodically checking an API for new data
Webhook	`webhook()`	`IWebhookFunctions`	`webhooks: [...]`	External service sends HTTP requests to n8n

ALWAYS set inputs: [] on trigger nodes — triggers have NO inputs
ALWAYS include 'trigger' in the group array
ALWAYS double-wrap emitted data: this.emit([[items]]) — outer array = outputs, inner array = items
ALWAYS provide manualTriggerFunction for event triggers so "Test Workflow" works in the editor
ALWAYS implement closeFunction when your trigger allocates resources (intervals, connections, listeners)