n8n-nodes-mongo-change-stream-trigger

This is an n8n community node. It lets you use MongoDB Change Streams in your n8n workflows.

MongoDB Change Streams allow applications to access real-time data changes without complex polling. This node listens for changes in MongoDB collections and triggers workflows when documents are inserted, updated, deleted, or when collections are modified.

n8n is a fair-code licensed workflow automation platform.

Installation
Operations
Credentials
Compatibility
Usage
Resources

Installation

Follow the installation guide in the n8n community nodes documentation.

Operations

This node works as a trigger that starts workflows when changes occur in MongoDB:

• Insert: Triggers when new documents are added to a collection
• Update: Triggers when existing documents are modified
• Replace: Triggers when documents are replaced
• Delete: Triggers when documents are removed
• Drop: Triggers when collections are dropped
• Rename: Triggers when collections are renamed

Credentials

You need to set up MongoDB credentials:

1. Create a new MongoDB connection in n8n (Credentials → New → MongoDB Trigger API)
2. Enter your MongoDB connection string (e.g., mongodb://username:password@localhost:27017)
3. The user needs at least read permissions on the target database and collection

Note: For change streams to work, your MongoDB deployment must be:

• A replica set or sharded cluster (not a standalone instance)
• MongoDB 3.6 or higher

Compatibility

• Requires n8n version 0.125.0 or later
• Requires MongoDB 3.6 or later (with replica set or sharded cluster)

Usage

1. Basic Setup:

   • Select the database and collection you want to monitor
   • Choose which operation types you want to trigger on (insert, update, delete, etc.)

2. Field Monitoring:

   • Use * to listen for any changes
   • Enter specific field names (comma-separated) to only trigger when these fields change

3. Filtering:

   • Add filters to only trigger when specific field values match your conditions
   • Example: Only trigger when status field equals completed

4. Output Format: The node produces a clean, readable output with:

   • Operation type (insert, update, etc.)
   • Timestamp of the change
   • Database and collection names
   • Document ID
   • Changed fields and values (for updates)
   • Complete document (for inserts)

Resources

• n8n community nodes documentation
• MongoDB Change Streams documentation
• MongoDB Node.js Driver documentation