Intelligent Facebook Messenger Chatbot with GPT-4o Mini and Message Memory

This n8n workflow creates an intelligent Facebook Messenger chatbot that can hold conversations with message memory, powered by GPT-4o Mini. It listens for incoming messages, processes them with an AI agent, and responds intelligently while remembering previous interactions.

What it does

This workflow automates the following steps:

1. Receives Facebook Messenger Messages: It acts as a webhook listener for incoming messages from Facebook Messenger.
2. Validates Webhook Requests: It checks if the incoming request is a valid message event or a webhook verification request.
3. Handles Webhook Verification: If it's a verification request, it responds with the challenge token.
4. Extracts Message Details: For actual messages, it extracts the sender ID and the message text.
5. Prepares Message for AI: It formats the incoming message and previous conversation history (if any) for the AI agent.
6. Engages AI Agent: It uses an AI Agent (powered by an OpenAI Chat Model) with a simple memory to generate a coherent and context-aware response.
7. Sends Response to Facebook Messenger: It sends the AI-generated response back to the user on Facebook Messenger.

Prerequisites/Requirements

To use this workflow, you will need:

• n8n Instance: A running n8n instance.
• Facebook Page and App: A Facebook Page and a Facebook Developer App configured for Messenger integration. You'll need:
  • A Page Access Token
  • A App Secret
  • A Verify Token (for webhook setup)
• OpenAI API Key: An API key for OpenAI to use the GPT-4o Mini chat model.
• LangChain Nodes: Ensure you have the @n8n/n8n-nodes-langchain package installed in your n8n instance.

Setup/Usage

1. Import the Workflow: Import the provided JSON into your n8n instance.
2. Configure Webhook Node (Node 47 - Webhook):
   • Set the "HTTP Method" to POST.
   • Note down the "Webhook URL" after saving the workflow. You will need this for Facebook Messenger webhook setup.
3. Configure HTTP Request Node (Node 19 - HTTP Request):
   • This node is responsible for sending messages back to Facebook.
   • Set the URL to https://graph.facebook.com/v19.0/me/messages?access_token={{ $env.FACEBOOK_PAGE_ACCESS_TOKEN }}.
   • Set the "Request Method" to POST.
   • Set the "Body Content Type" to JSON.
   • In the "Body Parameters", ensure it constructs a JSON payload with recipient.id and message.text from the AI's response.
   • You will need to set a credential for Facebook or provide the FACEBOOK_PAGE_ACCESS_TOKEN as an environment variable.
4. Configure OpenAI Chat Model Node (Node 1153 - OpenAI Chat Model):
   • Select your OpenAI credential or create a new one, providing your OpenAI API Key.
   • Ensure the "Model" is set to gpt-4o-mini or your preferred chat model.
5. Configure AI Agent Node (Node 1119 - AI Agent):
   • Ensure the "Language Model" is set to the "OpenAI Chat Model" node.
   • Ensure the "Memory" is set to the "Simple Memory" node.
6. Configure Facebook Webhook:
   • Go to your Facebook Developer App dashboard.
   • Navigate to the "Messenger" product and then "Webhooks".
   • Click "Add Callback URL".
   • Paste the "Webhook URL" from n8n's Webhook node (Node 47).
   • Enter the "Verify Token" that you've configured in your n8n Webhook node (Node 47).
   • Subscribe to the messages and messaging_postbacks events.
   • Ensure your Facebook Page is subscribed to the webhook.
7. Activate the Workflow: Toggle the workflow to "Active" in n8n.

Your intelligent Facebook Messenger chatbot is now ready to interact! Send a message to your Facebook Page, and the AI will respond, remembering your conversation history.