n8n Workflow: Send Private Welcome Messages to New WhatsApp Group Members with Evolution API

This n8n workflow automates the process of sending personalized welcome messages to new members joining a WhatsApp group. It integrates with the Evolution API to detect new participants and delivers a private message to them, ensuring a warm and automated onboarding experience.

What it does

This workflow streamlines the welcome process for WhatsApp groups by:

1. Triggering on a Webhook: It listens for incoming data, likely from a system that detects new WhatsApp group members (e.g., Evolution API webhook for group events).
2. Filtering for New Participants: It checks if the incoming event signifies a new participant joining the group.
3. Preparing the Welcome Message: It constructs a personalized welcome message, likely using data from the new participant event.
4. Sending a Private Message: It uses the Evolution API to send this private welcome message to the new group member.
5. Introducing a Delay: It includes a short delay before sending the message, which can help prevent rate limiting issues or make the message delivery feel more natural.

Prerequisites/Requirements

To use this workflow, you will need:

• n8n Instance: A running n8n instance (self-hosted or cloud).
• Evolution API Account: An active Evolution API account with access to WhatsApp functionalities.
• Evolution API Webhook: Your Evolution API instance should be configured to send webhooks to n8n when new members join a WhatsApp group.
• WhatsApp Group: A WhatsApp group where new members will be joining.

Setup/Usage

1. Import the Workflow: Import the provided JSON into your n8n instance.
2. Configure the Webhook Trigger:
   • Open the "Webhook" node.
   • Copy the "Webhook URL". This URL needs to be configured in your Evolution API settings as the endpoint for group participant events.
3. Configure the "Edit Fields" (Set) Node:
   • Review the fields being set. This node is likely used to extract and format data (like the new member's number and group ID) from the incoming webhook payload. Adjust expressions as needed based on your Evolution API webhook structure.
4. Configure the "Filter" Node:
   • Ensure the conditions in the "Filter" node correctly identify events where a new participant has joined the group. This typically involves checking specific fields in the webhook payload (e.g., event.type, action, participant_added).
5. Configure the "HTTP Request" Node:
   • This node is responsible for sending the private welcome message via the Evolution API.
   • Method: Should be POST.
   • URL: Set this to your Evolution API endpoint for sending messages (e.g., https://your-evolution-api-instance.com/message/send/text).
   • Headers: Add any necessary headers, such as Authorization with your Evolution API key or token.
   • Body: Configure the JSON body to include the recipient's WhatsApp number and the welcome message text. You will likely use expressions to dynamically insert the new member's number and a personalized message.
     • Example message body structure (adjust according to Evolution API documentation):

       {
         "number": "{{ $json.newMemberNumber }}",
         "text": "Hello {{ $json.newMemberName }}, welcome to our WhatsApp group! We're glad to have you here."
       }
       

6. Configure the "Wait" Node:
   • Adjust the delay duration as desired. A few seconds (e.g., 5-10 seconds) is usually sufficient.
7. Activate the Workflow: Once configured, activate the workflow in n8n.

Now, whenever a new member joins your configured WhatsApp group and your Evolution API sends a webhook to n8n, this workflow will automatically send them a private welcome message.