Module 3 Lesson 1: Trigger Nodes

Every journey begins with a first step. In n8n, that step is the Trigger Node. It defines the "Who/What/When" that starts your automation.

1. The Schedule Trigger (Cron)

This starts a workflow at a specific time.

• "Every morning at 8:00 AM."
• "Every 5 minutes."
• "The 1st day of every month."
• Best for: Weekly reports, database backups, or social media scheduling.

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2. The Webhook Trigger (Real-Time)

This is the fastest trigger. n8n gives you a URL. When any external app (like Typeform or GitHub) sends "POST" data to that URL, n8n starts immediately.

• Best for: New leads, security alerts, and payment notifications.
• Tip: Always use the "Production" URL for real use, and "Test" URL for building.

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Visualizing the Process

graph TD
    Start[Input] --> Process[Processing]
    Process --> Decision{Check}
    Decision -->|Success| End[Complete]
    Decision -->|Retry| Process

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3. The App Triggers (Polling)

Some nodes, like Google Sheets or Gmail, have built-in triggers.

• "On New Email."
• "On Row Added."
• Behind the scenes, n8n "Polls" (checks) the app every few minutes to see if anything is new.

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4. The "Manual" Trigger

This is the big orange "Execute Workflow" button.

• You use this 99% of the time while Building and Testing.

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5. Multiple Triggers

Did you know you can have 2 or 3 triggers for the same workflow?

• You can have a "Schedule" that runs once a day, BUT a "Webhook" that allows you to trigger it manually from a button in a different app.

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Exercise: The Trigger Lab

1. Add a Schedule node. Set it to run every "10 seconds."
2. Connect a No-Op node.
3. Click "Execute Workflow." Does it run automatically?
4. Find the "Webhook" node. Copy the "Test URL."
5. Using a tool like Postman or curl, send a message to that URL. Does n8n show the data?
6. Why is a Webhook better for your battery and server than a Schedule that runs every second?

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Summary

Triggers are the "Input" of your automation. By choosing the right trigger, you control the "Freshness" of your data and the "Speed" of your response to the outside world.

Next Lesson: Doing the heavy lifting: Core Action Nodes: Doing the work.