How to integrate Facebook MCP with LangChain

This guide walks you through connecting Facebook to LangChain using the Composio tool router. By the end, you'll have a working Facebook agent that can post new product launch on our page, upload latest event photos to album, reply to comments on latest post through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Facebook account through Composio's Facebook MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Facebook logoFacebook
Oauth2

Facebook is a social media and advertising platform for businesses and creators. It helps you connect, share, and manage content across your public Facebook Pages.

39 Tools

Introduction

This guide walks you through connecting Facebook to LangChain using the Composio tool router. By the end, you'll have a working Facebook agent that can post new product launch on our page, upload latest event photos to album, reply to comments on latest post through natural language commands.

This guide will help you understand how to give your LangChain agent real control over a Facebook account through Composio's Facebook MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Facebook with

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Connect your Facebook project to Composio
  • Create a Tool Router MCP session for Facebook
  • Initialize an MCP client and retrieve Facebook tools
  • Build a LangChain agent that can interact with Facebook
  • Set up an interactive chat interface for testing

What is LangChain?

LangChain is a framework for developing applications powered by language models. It provides tools and abstractions for building agents that can reason, use tools, and maintain conversation context.

Key features include:

  • Agent Framework: Build agents that can use tools and make decisions
  • MCP Integration: Connect to external services through Model Context Protocol adapters
  • Memory Management: Maintain conversation history across interactions
  • Multi-Provider Support: Works with OpenAI, Anthropic, and other LLM providers

What is the Facebook MCP server, and what's possible with it?

The Facebook MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Facebook Page account. It provides structured and secure access to your Facebook Pages, so your agent can perform actions like publishing posts, managing comments, uploading media, and handling page roles on your behalf.

  • Automated content publishing: Have your agent create new posts, photo posts, or video posts directly to your Facebook Page, keeping your audience engaged without manual effort.
  • Media management: Effortlessly upload photos to existing albums or create new albums for organized visual storytelling on your Page.
  • Interactive engagement: Let your agent add reactions, post comments, or reply to comments, fostering genuine interaction with your followers.
  • Page moderation and cleanup: Ask your agent to delete unwanted comments or posts, helping you keep your Facebook Page professional and on-brand.
  • Page team management: Assign tasks or roles to users for your Facebook Page, streamlining collaboration and access control.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step10 STEPS
1

Prerequisites

Before starting this tutorial, make sure you have:
  • Python 3.10 or higher installed on your system
  • A Composio account with an API key
  • An OpenAI API key
  • Basic familiarity with Python and async programming
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • Keep the API key safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

npm install @composio/langchain @langchain/core @langchain/openai @langchain/mcp-adapters dotenv

Install the required packages for LangChain with MCP support.

What's happening:

  • @composio/langchain provides Composio integration for LangChain
  • @langchain/mcp-adapters enables MCP client connections
  • @langchain/core is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_composio_user_id_here
OPENAI_API_KEY=your_openai_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates your requests to Composio's API
  • COMPOSIO_USER_ID identifies the user for session management
  • OPENAI_API_KEY enables access to OpenAI's language models
5

Import dependencies

import { Composio } from '@composio/core';
import { LangchainProvider } from '@composio/langchain';
import { MultiServerMCPClient } from "@langchain/mcp-adapters";
import { createAgent } from "langchain";
import * as readline from 'readline';
import 'dotenv/config';

dotenv.config();
What's happening:
  • We're importing LangChain's MCP adapter and Composio SDK
  • The dotenv/config import loads environment variables from your .env file
  • This setup prepares the foundation for connecting LangChain with Facebook functionality through MCP
6

Initialize Composio client

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.COMPOSIO_USER_ID;

if (!composioApiKey) throw new Error('COMPOSIO_API_KEY is not set');
if (!userId) throw new Error('COMPOSIO_USER_ID is not set');

async function main() {
    const composio = new Composio({
        apiKey: composioApiKey as string,
        provider: new LangchainProvider()
    });
What's happening:
  • We're loading the COMPOSIO_API_KEY from environment variables and validating it exists
  • Creating a Composio instance that will manage our connection to Facebook tools
  • Validating that COMPOSIO_USER_ID is also set before proceeding
7

Create a Tool Router session

const session = await composio.create(
    userId as string,
    {
        toolkits: ['facebook']
    }
);

const url = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Facebook tools
  • The create method takes the user ID and specifies which toolkits should be available
  • The returned session.mcp.url is the MCP server URL that your agent will use
  • This approach allows the agent to dynamically load and use Facebook tools as needed
8

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "facebook-agent": {
        transport: "http",
        url: url,
        headers: {
            "x-api-key": process.env.COMPOSIO_API_KEY
        }
    }
});

const tools = await client.getTools();

const agent = createAgent({ model: "gpt-5", tools });
What's happening:
  • We're creating a MultiServerMCPClient that connects to our Facebook MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • getTools() retrieves all available Facebook tools that the agent can use
  • We're creating a LangChain agent using the GPT-5 model
9

Set up interactive chat interface

let conversationHistory: any[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log("Ask any Facebook related question or task to the agent.\n");

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
});

rl.prompt();

rl.on('line', async (userInput: string) => {
    const trimmedInput = userInput.trim();

    if (['exit', 'quit', 'bye'].includes(trimmedInput.toLowerCase())) {
        console.log("\nGoodbye!");
        rl.close();
        process.exit(0);
    }

    if (!trimmedInput) {
        rl.prompt();
        return;
    }

    conversationHistory.push({ role: "user", content: trimmedInput });
    console.log("\nAgent is thinking...\n");

    const response = await agent.invoke({ messages: conversationHistory });
    conversationHistory = response.messages;

    const finalResponse = response.messages[response.messages.length - 1]?.content;
    console.log(`Agent: ${finalResponse}\n`);
        
        rl.prompt();
    });

    rl.on('close', () => {
        console.log('\n👋 Session ended.');
        process.exit(0);
    });
What's happening:
  • We initialize an empty conversationHistory list to maintain context across interactions
  • A readline interface is used to continuously accept user input from the command line
  • When a user types a message, it's added to the conversation history and sent to the agent
  • The agent processes the request using the invoke() method with the full conversation history
  • Users can type 'exit', 'quit', or 'bye' to end the chat session gracefully
10

Run the application

main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});
What's happening:
  • We call the main() function to start the application

Complete Code

Here's the complete code to get you started with Facebook and LangChain:

import { Composio } from '@composio/core';
import { LangchainProvider } from '@composio/langchain';
import { MultiServerMCPClient } from "@langchain/mcp-adapters";  
import { createAgent } from "langchain";
import * as readline from 'readline';
import 'dotenv/config';

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.COMPOSIO_USER_ID;

if (!composioApiKey) throw new Error('COMPOSIO_API_KEY is not set');
if (!userId) throw new Error('COMPOSIO_USER_ID is not set');

async function main() {
    const composio = new Composio({
        apiKey: composioApiKey as string,
        provider: new LangchainProvider()
    });

    const session = await composio.create(
        userId as string,
        {
            toolkits: ['facebook']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "facebook-agent": {
            transport: "http",
            url: url,
            headers: {
                "x-api-key": process.env.COMPOSIO_API_KEY
            }
        }
    });
    
    const tools = await client.getTools();
  
    const agent = createAgent({ model: "gpt-5", tools });
    
    let conversationHistory: any[] = [];
    
    console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
    console.log("Ask any Facebook related question or task to the agent.\n");
    
    const rl = readline.createInterface({
        input: process.stdin,
        output: process.stdout,
        prompt: 'You: '
    });

    rl.prompt();

    rl.on('line', async (userInput: string) => {
        const trimmedInput = userInput.trim();
        
        if (['exit', 'quit', 'bye'].includes(trimmedInput.toLowerCase())) {
            console.log("\nGoodbye!");
            rl.close();
            process.exit(0);
        }
        
        if (!trimmedInput) {
            rl.prompt();
            return;
        }
        
        conversationHistory.push({ role: "user", content: trimmedInput });
        console.log("\nAgent is thinking...\n");
        
        const response = await agent.invoke({ messages: conversationHistory });
        conversationHistory = response.messages;
        
        const finalResponse = response.messages[response.messages.length - 1]?.content;
        console.log(`Agent: ${finalResponse}\n`);
        
        rl.prompt();
    });

    rl.on('close', () => {
        console.log('\nSession ended.');
        process.exit(0);
    });
}

main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});

Conclusion

You've successfully built a LangChain agent that can interact with Facebook through Composio's Tool Router.

Key features of this implementation:

  • Dynamic tool loading through Composio's Tool Router
  • Conversation history maintenance for context-aware responses
  • Async Python provides clean, efficient execution of agent workflows
You can extend this further by adding error handling, implementing specific business logic, or integrating additional Composio toolkits to create multi-app workflows.
TOOLS

Supported Tools

Every Facebook action and event your agent gets out of the box.

Assign Page Task

Assigns tasks/roles to a business-scoped user or system user for a specific Facebook Page.

Create Comment

Creates a comment on a Facebook post or replies to an existing comment.

Create Photo Album

Creates a new photo album on a Facebook Page.

Create Photo Post

Creates a photo post on a Facebook Page.

Create Post

Creates a new text or link post on a Facebook Page.

Create Video Post

Creates a video post on a Facebook Page.

Delete Comment

Deletes a Facebook comment.

Delete Post

Permanently deletes a Facebook Page post.

Get Comment

Retrieves details of a specific Facebook comment.

Get Comments

Retrieves comments from a Facebook post or comment (for replies).

Get Conversation Messages

Retrieves messages from a specific conversation.

Get Current User

Validates the access token and retrieves the authenticated user's own profile via /me.

Get Message Details

Retrieves details of a specific message sent or received by the Page.

Get Page Conversations

Retrieves a list of conversations between users and the Page.

Get Page Details

Fetches details about a specific Facebook Page.

Get Page Insights

Retrieves analytics and insights for a Facebook Page.

Get Page Photos

Retrieves photos from a Facebook Page.

Get Page Posts

Retrieves posts from a Facebook Page.

Get Page Roles

Retrieves a list of people and their tasks/roles on a Facebook Page.

Get Page Tagged Posts

Retrieves posts where a Facebook Page is tagged or mentioned.

Get Page Videos

Retrieves videos from a Facebook Page.

Get Post

Retrieves details of a specific Facebook post.

Get Post Insights

Retrieves analytics and insights for a specific Facebook post.

Get Post Reactions

Retrieves reactions (like, love, wow, etc.

Get Scheduled Posts

Retrieves scheduled and unpublished posts for a Facebook Page.

Add Reaction

Adds a LIKE reaction to a Facebook post or comment.

List Managed Pages

Retrieves a list of Facebook Pages that the user manages (not personal profiles), including page details, access tokens, and tasks.

Mark Message Seen

Marks a user's message as seen by the Page, visibly updating the read status in the user's conversation.

Publish Scheduled Post

Publishes a previously scheduled or unpublished Facebook post immediately.

Remove Page Task

Removes a user's tasks/access from a specific Facebook Page.

Reschedule Post

Changes the scheduled publish time of an unpublished Facebook post.

Send Media Message

Sends a media message (image, video, audio, or file) from the Page to a user.

Send Message

Sends a text message from a Facebook Page (not personal profiles) to a user via Messenger.

Toggle Typing Indicator

Shows or hides the typing indicator for a user in Messenger.

Unlike Post or Comment

Removes a like from a Facebook post or comment.

Update Comment

Updates an existing Facebook comment.

Update Page Settings

Updates settings for a specific Facebook Page.

Update Post

Updates an existing Facebook Page post.

Upload Photos Batch

Uploads multiple photo files in batch to a Facebook Page or Album.

FAQ

Frequently asked questions

With a standalone Facebook MCP server, the agents and LLMs can only access a fixed set of Facebook tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Facebook and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. LangChain fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Facebook tools.

Yes, absolutely. You can configure which Facebook scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Facebook data and credentials are handled as safely as possible.

Start with Facebook.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Facebook tool your agent needs.Free to start.

Start building