How to integrate Rocket reach MCP with LangChain

This guide walks you through connecting Rocket reach to LangChain using the Composio tool router. By the end, you'll have a working Rocket reach agent that can find verified email for linkedin profile, get direct dial number for company executive, lookup job title for specific contact through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Rocket reach account through Composio's Rocket reach MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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RocketReach is a professional contact lookup and verification platform for sales and recruiting. It helps teams find accurate emails, phone numbers, and social links to boost outreach success.

12 Tools

Introduction

This guide walks you through connecting Rocket reach to LangChain using the Composio tool router. By the end, you'll have a working Rocket reach agent that can find verified email for linkedin profile, get direct dial number for company executive, lookup job title for specific contact through natural language commands.

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

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

Also integrate Rocket reach with

OpenAI Agents SDKClaude Agent SDKClaude CodeClaude CoworkCodexOpenClawHermesCLIGoogle ADKVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

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

The Rocket reach MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your RocketReach account. It provides structured and secure access to professional contact information, so your agent can perform actions like finding verified emails, enriching lead profiles, searching for company details, and managing outreach research—all automatically on your behalf.

  • Find verified contact details: Instantly retrieve accurate email addresses, phone numbers, and social profiles for prospects or candidates from the RocketReach database.
  • Enrich and update lead profiles: Ask your agent to gather and supplement missing details about leads, including job titles, current companies, and social links.
  • Company lookup and research: Have your agent pull company background, industry, size, and key personnel information to inform outreach and targeting strategies.
  • List building and segmentation: Let your agent assemble lists of contacts based on filters like company, role, location, or industry, so you can streamline your outreach campaigns.
  • Contact verification and scoring: Direct your agent to check the deliverability and accuracy of contact details, helping you prioritize the best leads or candidates.

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 Rocket reach 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 Rocket reach 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: ['rocket_reach']
    }
);

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

Configure the agent with the MCP URL

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

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

Check Person Status

Tool to check the status of multiple person lookup requests.

Get RocketReach Account Info

Tool to retrieve account information for the authenticated user.

RocketReach Get Company Funding

Tool to retrieve funding details for a specified company.

Get Company Growth Metrics

Tool to get growth metrics for a specified company domain.

Get Company Industries

Tool to list industries associated with a specified company.

Get Company Size

Tool to retrieve size metrics of a company.

Get Company Tech Stack

Tool to get technology stack for a company by domain.

RocketReach Lookup Company

Tool to lookup a company's domain via RocketReach Company Lookup API.

RocketReach Lookup Person

Tool to lookup detailed person information from RocketReach.

Lookup Person and Company

Tool to lookup both person and company information in a single request.

List Companies

Tool to list companies by name or keyword.

Search People

Tool to search for people by name, title, or keywords.

FRAMEWORKS

How to build Rocket reach MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Rocket reach MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Rocket reach MCP with Claude Agent SDK

Claude Code logo

Claude Code

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Claude Cowork logo

Claude Cowork

Use Rocket reach MCP with Claude Cowork

Codex logo

Codex

Use Rocket reach MCP with Codex

OpenClaw logo

OpenClaw

Use Rocket reach MCP with OpenClaw

Hermes logo

Hermes

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CLI logo

CLI

Use Rocket reach MCP with CLI

Google ADK logo

Google ADK

Use Rocket reach MCP with Google ADK

Vercel AI SDK logo

Vercel AI SDK

Use Rocket reach MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Rocket reach MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Rocket reach MCP with LlamaIndex

CrewAI logo

CrewAI

Use Rocket reach MCP with CrewAI

FAQ

Frequently asked questions

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

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

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