How to integrate Apollo MCP with LangChain

This guide walks you through connecting Apollo to LangChain using the Composio tool router. By the end, you'll have a working Apollo agent that can bulk enrich profiles for new leads, add contacts to outreach sequence now, create a new sales deal for acme through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Apollo account through Composio's Apollo MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Apollo is a CRM and lead generation platform that helps businesses discover contacts and manage sales pipelines. Use it to streamline customer outreach and track your deals from one place.

48 Tools

Introduction

This guide walks you through connecting Apollo to LangChain using the Composio tool router. By the end, you'll have a working Apollo agent that can bulk enrich profiles for new leads, add contacts to outreach sequence now, create a new sales deal for acme through natural language commands.

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

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

Also integrate Apollo with

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Connect your Apollo project to Composio
  • Create a Tool Router MCP session for Apollo
  • Initialize an MCP client and retrieve Apollo tools
  • Build a LangChain agent that can interact with Apollo
  • 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 Apollo MCP server, and what's possible with it?

The Apollo MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Apollo account. It provides structured and secure access to your CRM and lead generation data, so your agent can create contacts, enrich organizations, manage deals, update account stages, and automate tasks for your sales pipeline—all on your behalf.

  • Contact and account creation: Instantly add new contacts or accounts to Apollo, linking them to organizations and stages to keep your CRM up to date with zero manual entry.
  • Bulk data enrichment: Rapidly enrich multiple people or organizations at once, leveraging Apollo's database to fill gaps and update your records with the latest information.
  • Sales opportunity and pipeline management: Let your agent create new deals, retrieve opportunity stages, and move accounts through your sales funnel to optimize pipeline performance.
  • Automated outreach sequencing: Add contacts to email sequences, making it easy to launch targeted campaigns and follow-ups without lifting a finger.
  • Task creation and label organization: Generate actionable Apollo tasks for your team and organize contacts or accounts with labels, so nothing slips through the cracks.

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 Apollo 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 Apollo 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: ['apollo']
    }
);

const url = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Apollo 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 Apollo tools as needed
8

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "apollo-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 Apollo MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • getTools() retrieves all available Apollo 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 Apollo 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 Apollo 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: ['apollo']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "apollo-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 Apollo 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 Apollo 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 Apollo action and event your agent gets out of the box.

Add Contacts to Sequence

Adds contacts to a specified Apollo email sequence and returns the contact details.

Bulk organization enrichment

Enriches data for up to 10 organizations simultaneously by providing a list of their base company domains (e.

Bulk people enrichment

Use to enrich multiple person profiles simultaneously with comprehensive data from Apollo's database.

Bulk update account stage

Bulk updates the stage for specified existing Apollo.

Create an Apollo account

Creates a new account in Apollo.

Bulk create Apollo accounts

Creates multiple accounts in Apollo.

Bulk create Apollo contacts

Tool to bulk create multiple contacts in Apollo with a single API call.

Create call record in Apollo

Tool to log call records in Apollo from external systems.

Create Apollo contact

Creates a new contact in Apollo.

Create custom field

Creates a new custom field in Apollo.

Create Apollo deal

Creates a new sales opportunity (deal) in Apollo.

Create Apollo Task

Tool to create a single task in Apollo.

Get Account by ID

Tool to retrieve detailed information about a specific account by its Apollo ID.

Check Apollo API key status

Tool to check whether the provided Apollo API key is valid and accepted by Apollo (health/auth check).

Get Apollo Contact

Retrieves detailed information about a specific contact by its ID.

Get Apollo deal

Retrieves information about a specific deal by its ID.

Get Labels

Retrieves all labels from Apollo.

Get opportunity stages

Retrieves all configured opportunity (deal) stages from the Apollo.

Get Organization by ID

Retrieves complete information about a specific organization by its Apollo ID.

Get Organization Job Postings

Retrieves paginated job postings for a specified organization by its ID, optionally filtering by domain; ensure `organization_id` is a valid identifier.

Get typed custom fields

Retrieves all typed custom field definitions available in the Apollo.

List Apollo account stages

Retrieves the IDs for all available account stages in your team's Apollo account.

List apollo contact stages

Retrieves all available contact stages from an Apollo account, including their unique IDs and names.

List Apollo deals

Retrieves a list of deals from Apollo, using Apollo's default sort order if 'sort_by_field' is omitted.

List email accounts

Retrieves all email accounts and their details for the authenticated user; takes no parameters.

List Fields

Retrieves all field definitions from Apollo.

List Apollo Users

Retrieves a list of all users (teammates) associated with the Apollo account, supporting pagination via `page` and `per_page` parameters.

Enrich organization data

Fetches comprehensive organization enrichment data from Apollo.

Search organizations in Apollo

Searches Apollo's database for organizations using various filters; consumes credits on every call (unavailable on free plans) — avoid re-running identical queries and surface quota errors rather than retrying.

Enrich person with Apollo

Enriches and retrieves information for a person from Apollo.

Apollo people search

Searches Apollo's contact database for people using various filters; results capped at 50,000 records and does not enrich contact data.

Search Apollo Accounts

Searches for accounts within your existing Apollo.

Search for Calls

Searches for call records in Apollo.

Search Apollo contacts

Searches Apollo contacts using keywords, stage IDs (from 'List Contact Stages' action), or sorting (max 50,000 records; `sort_ascending` requires `sort_by_field`).

Search news articles

Tool to search for news articles about companies in Apollo's database.

Search outreach emails

Tool to search for outreach emails sent through Apollo sequences.

Search sequences

Searches for sequences (e.

Search tasks

Searches for tasks in Apollo.

Update an Apollo account

Updates specified attributes of an existing account in Apollo.

Update account ownership

Updates the ownership of multiple Apollo accounts to a specified user.

Update Apollo call record

Tool to update an existing call record in Apollo.

Update Apollo contact details

Tool to update an existing contact's information in Apollo.

Update contact ownership

Updates the ownership of specified Apollo contacts to a given Apollo user, who must be part of the same team.

Bulk update Apollo contacts

Tool to bulk update multiple Apollo contacts with a single API call.

Update contact stage

Updates the stage for one or more existing contacts in Apollo.

Update contact status in sequence

Updates a contact's status within a designated Apollo sequence, but cannot set the status to 'active'.

Update Apollo deal

Updates specified fields of an existing Apollo.

View API Usage Stats

Fetches Apollo API usage statistics and rate limits for the connected team.

FAQ

Frequently asked questions

With a standalone Apollo MCP server, the agents and LLMs can only access a fixed set of Apollo tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Apollo 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 Apollo tools.

Yes, absolutely. You can configure which Apollo 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 Apollo data and credentials are handled as safely as possible.

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