Automate Matrix Room Creation and Member Invites with n8n

Opening Problem Statement

Meet Alex, a community manager for a growing tech forum that uses Matrix for team discussions and user engagement. Every time a new project kicks off, Alex spends hours creating new chat rooms, manually inviting members from existing rooms, and sending out welcome messages to get everyone aligned. This repetitive manual work not only wastes valuable time—around 3 hours per project setup—but can also lead to missed invites and inconsistent communication, causing confusion and delays.

If you’re like Alex, juggling multiple Matrix rooms and member lists, you know how tedious it can be to keep everything in sync manually. Mistakes creep in, and valuable engagement opportunities slip by unnoticed.

What This Automation Does

This unique n8n workflow automates the entire process of setting up a new Matrix chat room, inviting members from a specified existing room, and sending a welcome message automatically. Here’s what happens when it runs:

• Creates a new Matrix room with a given room name and alias, eliminating manual room setup.
• Fetches the current user’s account info to manage membership logic.
• Retrieves members from a specified existing Matrix room to replicate invitations efficiently.
• Invites each eligible member (skipping the current user) to the newly created room automatically.
• Sends a custom welcome message to the newly created room, ensuring clear communication from day one.
• Handles control logic with conditional checks and a no-operation fallback for unattended cases.

By automating these steps, Alex can save 3+ hours per project setup and avoid manual invitation errors.

Prerequisites ⚙️

• n8n account with access to install and configure workflows.
• Matrix account and API credentials configured in n8n for the Matrix node (credentials named “matrixApi”).
• Basic knowledge of how Matrix rooms and members are structured.

Step-by-Step Guide

Step 1: Trigger the Workflow Manually

In n8n, click the + New Workflow button, then add a Manual Trigger node named On clicking ‘execute’. This allows you to start the workflow on demand for testing and executions.

Expected outcome: When you press Execute, the workflow starts the room creation process.

Common mistake: Forgetting to connect this node as the starting point.

Step 2: Create a New Matrix Room

Add a Matrix node configured to create a room. Set the Resource to “room” and specify your desired Room Name and Room Alias. For example, “n8n” for the room name and “discussion-n8n” for the alias.

Visual description: You should see JSON output confirming the new room’s room_id.

Step 3: Get Current Account Information

Add another Matrix node to fetch the logged-in user’s account info. Set the Resource to “account”. This is necessary to exclude the current user from being re-invited.

Outcome: You’ll get JSON data including the user_id which will be used in conditional checks.

Step 4: Fetch Members from an Existing Room

Add another Matrix node configured to get the room members of an existing Matrix room by providing its Room ID. Set Resource to “roomMember”.

Example Room ID: !cMUIsUgevrhCoeMkSG:matrix.org

Visual cue: You should receive a list of members in the node’s JSON output.

Step 5: Apply Conditional Logic to Invite Members

Add an If node to compare the user_id of each member to the logged-in user’s user_id from step 3 to avoid self-invites. Configure the string condition to check if these IDs are not equal.

Expected functionality: Only invite members who are not the current user.

Step 6: Invite Members to the New Room

In one branch of the If node’s true output, add a Matrix node configured to invite users to the new room. Provide the room_id from step 2 and the user_id from the If node.

Expected result: Eligible members get invited automatically.

Step 7: Send a Welcome Message to the New Room

Add another Matrix node after the invitations that sends a text message to the new room. Set text to “Welcome to n8n!” or your personalized message and specify the room_id.

What you’ll see: A welcome message appears in the new Matrix room.

Step 8: Handle Non-Invitation Cases Gracefully

The false condition branch of the If node connects to a NoOp node which essentially does nothing but keeps the workflow clean and prevents errors.

Customizations ✏️

• Change room name and alias: Modify the Room Name and Room Alias in the first Matrix node to suit your community or project.
• Customize the welcome message: In the final Matrix node sending the message, update the text field with personalized greetings or instructions.
• Invite selective users: Add extra conditions in the If node to invite only members who match certain roles or attributes by fetching additional info via Matrix nodes.
• Automate workflow trigger: Replace the Manual Trigger with a Webhook node if you’d like to trigger the workflow externally.
• Add logging: Insert a Set node or write to a Google Sheet after invitations to keep track of invited users.

Troubleshooting 🔧

Problem: “user_id” is undefined or missing in If node

Cause: The Matrix nodes fetching user or member data might not be configured correctly or credentials are invalid.

Solution: Double-check the Matrix node credentials, and confirm API access. Verify the previous node outputs contain the expected user_id fields.

Problem: Invitations not sent to members

Cause: The If node condition may be filtering out all members due to incorrect comparison or data path.

Solution: Review the conditional expression in the If node ensuring it compares the correct fields like {{$node["Matrix1"].json["user_id"]}} and {{$node["Matrix2"].json["user_id"]}}. Test with sample data.

Problem: Matrix API rate limits or errors

Cause: Sending too many invitations too quickly or missing required permissions.

Solution: Pace invites, add delays or error handling nodes, and verify user permissions in Matrix.

Pre-Production Checklist ✅

• Ensure Matrix API credentials named “matrixApi” are correctly set up in n8n.
• Test each Matrix node individually to verify correct responses (e.g., account info, room creation, member list retrieval).
• Validate that the room alias and name do not clash with existing rooms.
• Simulate member invites with a test room and user to ensure the If condition works as intended.
• Back up important data or workflow versions before deployment.

Deployment Guide

Once satisfied with tests, activate the workflow in n8n by toggling it from inactive to active. Run manual tests to monitor behavior and ensure members are invited and messages sent as expected.

Consider monitoring logs for errors and adding notifications or alerts via other nodes for production stability.

FAQs

• Can I use a webhook instead of manual trigger? Yes, you can replace the Manual Trigger node with a Webhook node to trigger externally.
• Are Matrix API limits a concern? Yes, high volume invites may hit rate limits; adding delays or batching invites is recommended.
• Is this workflow secure? Data stays within your Matrix server and n8n environment, but always secure your credentials.
• Can I invite members from multiple rooms? Currently, this workflow invites from one specified room, but you can extend it to iterate through multiple rooms with added nodes.

Conclusion

By deploying this n8n Matrix automation workflow, you have eliminated hours of manual room management and member invitations. Alex no longer spends 3+ hours duplicating room setups and avoids invitation errors, leading to more engaged and synchronized communities.

Next, consider automating message moderation in Matrix, syncing invite workflows with user onboarding systems, or creating dynamic rooms based on project phases—all achievable with n8n’s Matrix nodes and conditional logic.

Feel confident to build upon this solid foundation and save more time on communication automation!