How to create a sub-workflow in n8n?

How to Create a Sub-Workflow in n8n

Sub-workflows in n8n are reusable workflow components that can be called from other workflows — similar to functions in programming. They promote reusability and keep complex workflows organized.

Creating a Sub-Workflow

Step 1: Create the sub-workflow

1. In n8n, create a new workflow
2. Add a Workflow Trigger node as the starting point (set it to accept "Execute Workflow" trigger)
3. Build the sub-workflow logic
4. Use a Set node or Return to define what data to pass back
5. Save with a descriptive name like "Send Email Notification"

Step 2: Call it from a parent workflow

Add an Execute Workflow node in your main workflow and select the sub-workflow by name.

n8n Sub-Workflow Types

Practical Example

Sub-workflow: "Process Customer Data"

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[Workflow Trigger (Execute Workflow)]
        ↓
[Validate Input] — check required fields
        ↓
[Enrich Data] — add timestamp, format name
        ↓
[Return enriched_customer]

Parent workflow calling it:

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[New Customer webhook arrives]
        ↓
[Execute Workflow: "Process Customer Data"]
  Input: {name: "John", email: "john@example.com"}
        ↓
[Use result: enriched_customer]
        ↓
[Save to Database]
        ↓
[Send Welcome Email]

Configuration in n8n

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// Execute Workflow node settings
{
  "workflowId": "xyz123",  // ID of sub-workflow
  "mode": "executeWorkflow",
  "waitForSubWorkflow": true,  // Sync or async
  "inputData": {
    "customer": "{{ $json.customer_data }}"
  }
}

Passing Data To/From Sub-Workflows

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// In sub-workflow — access input data
const inputData = $input.all()[0].json;
const customerName = inputData.customer.name;

// Return data from sub-workflow (using Set node)
return [{
  json: {
    processed: true,
    enriched_customer: {
      ...inputData.customer,
      processed_at: new Date().toISOString(),
      display_name: customerName.trim()
    }
  }
}];

Benefits of Sub-Workflows

Best Practices

• Name sub-workflows clearly: "Send Slack Alert", "Validate Email Address"
• Keep sub-workflows focused on ONE task
• Document expected input/output in the workflow description
• Use sub-workflows for any logic used in 2+ places
• Version control your n8n workflows via GitHub integration