Automated Facebook Comment Management with GPT-4o and LangChain

Description

🤖 Facebook AI Agent with MCP Server – Built for Smart Engagement and Automation

Hi! I’m Amanda 🥰😘 — I build intelligent automations with n8n and Make.
This powerful workflow was designed to help teams automatically handle Facebook page interactions with AI. Using Meta Graph API, LangChain, MCP Server, and GPT-4o, it allows your AI agent to search for posts, read captions, fetch comments, and even reply or message followers, all through structured tools.

🔧 What the workflow does

Searches for recent media using Facebook Page ID and access token
Reads and extracts captions or media URLs
Fetches comments and specific replies from each post
Replies to comments automatically with GPT-generated responses
Sends direct messages to followers who commented
Maps user input and session to keep memory context via LangChain
Communicates via Server-Sent Events (SSE) using your MCP Server URL

🧰 Nodes & Tech Used

LangChain Agent + Chat Model with GPT-4o
Memory Buffer for session memory
toolHttpRequest to search media, comments, and send replies
MCP Trigger and MCP Tool (custom SSE connection)
Set node for input and variable assignment
Webhook and JSON for Facebook API structure

⚙️ Setup Instructions

Create your Facebook App in Meta Developer Portal
Add your Facebook Page ID and Access Token in the Set node
Update the MCP Server Tool URL in the MCP Facebook node
Use your n8n server URL (e.g. https://yourdomain.com/mcp/server/facebook/sse)
Trigger the workflow using the included LangChain Chat Trigger
Interact via text to ask the agent to:
“Get latest posts”
“Reply to comment X with this message”
“Send DM to this user about...”

👥 Who this is for

Social media teams managing multiple Facebook pages
Brands automating engagement with followers
Agencies creating smart, autonomous digital assistants
Developers building conversational bots for Facebook

✅ Requirements

Meta Graph API access
Facebook Page (with permissions)
n8n instance (Cloud or Self-hosted)
MCP Server configured (SSE Endpoint enabled)
OpenAI API Key (for GPT-4o + LangChain)

🌐 Want to use this workflow?

❤️ Buy workflows: https://iloveflows.com
☁️ Try n8n Cloud: https://n8n.partnerlinks.io/amanda