What Is a Trigger in n8n? A Visual Guide

By Robert Breen · Published October 1, 2026 · From the free lesson Build an AI Follow-Up Agent for HVAC Service Calls

A visual guide to triggers: the event that starts an automation, like a chat message, a schedule or a form, shown in a real HVAC n8n lesson.

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Swipe or scroll sideways for all 4 slides. The whole guide is written out below.

The guide in text

Trigger: The event that starts a workflow: a new email, a form submission, a chat message, a set time or a click. Nothing after it runs until the trigger fires.

Pick the event that starts the job

At Cedar Ridge Heating & Air (made up), the office decides when follow-ups go out, so the trigger is a chat message.

Choose it on purpose

Ask what event really starts the job in your office, then pick the trigger that matches.
Fetch a test event so you can see the trigger's output fields first.
App and schedule triggers only fire on their own after the workflow is published.

The full definition: What is a trigger in automation? in the AI glossary, with an example from a free lesson, common confusions and tips.

Businesses and people in the examples are made up. The steps, screens and wording come from the free lesson and the Stepthrough glossary and prompt library.

Do it yourself, free

Build an AI Follow-Up Agent for HVAC Service Calls. Build an AI agent for Cedar Ridge Heating & Air that writes follow-up messages for completed service calls and saves them to Google Sheets — chat trigger, AI Agent, system prompt, model, memory, and… You do every step yourself in a practice copy of n8n, it checks your work as you go, and “Do it for me” finishes any step you get stuck on. Free, and nothing touches your real accounts.

Start the free lesson

Or read the full step-by-step guide

Plain-English definitions, each with an example from a free lesson.

Trigger AI agent API key API usage billing Append row Brand voice Chat Trigger Chatbot

The full AI glossary

Customer call notes summary prompt: Turn rough phone-call notes into a clean customer record: what they reported, what you promised and the next step, plus a short…
Email subject lines prompt: Get ten honest subject lines for a finished email, each with preview text and a character count, grouped by approach so you can…
Home maintenance tips email prompt: Write a seasonal home tips email from your own techs' advice: practical, safe for homeowners, one soft offer, and no scare…
Job completion summary prompt: Turn a technician's closing notes into a clear record for the customer: work done, what was installed and tested, warranty, and…

All free prompt templates

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