How to integrate Mailcoach MCP with LangChain

This guide walks you through connecting Mailcoach to LangChain using the Composio tool router. By the end, you'll have a working Mailcoach agent that can create a new email campaign for product launch, add a subscriber to the weekly newsletter list, tag all subscribers interested in webinars through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Mailcoach account through Composio's Mailcoach MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Get started for free Get a demo

Mailcoach

Api Key

Mailcoach is an email marketing platform for managing campaigns and subscribers. It helps you reach your audience efficiently with streamlined email delivery and automation.

56 Tools

Managed auth

Connect Mailcoach without auth hassles

We manage OAuth, API keys, token refresh, and scopes — you just build.

Try for free

Introduction

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

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

Also integrate Mailcoach with

OpenAI Agents SDK Claude Agent SDK Claude Code Claude Cowork Codex OpenClaw Hermes CLI Google ADK Vercel AI SDK Mastra AI LlamaIndex CrewAI

TL;DR

Here's what you'll learn:

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

The Mailcoach MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Mailcoach account. It provides structured and secure access to your email marketing platform, so your agent can manage campaigns, organize subscriber lists, create templates, and automate email workflows on your behalf.

Email campaign creation and scheduling: Direct your agent to launch new campaigns, send emails to specific lists, or set up campaign schedules based on your marketing needs.
Subscriber list and segmentation management: Let your agent create new email lists, add or confirm subscribers, and apply tags for better audience segmentation and targeting.
Template management and customization: Instruct your agent to create, update, or organize reusable email templates and transactional templates for efficient campaign building.
Automated suppression and bounce handling: Have your agent add suppressions for bounced or blocked addresses, keeping your lists clean and compliant with deliverability best practices.
Bulk subscriber import and data enrichment: Enable your agent to import subscribers via CSV, append new data to existing imports, and streamline growth of your contact lists.

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:

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

Step-by-step Guide

Step by step10 STEPS

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

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.

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

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

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 Mailcoach functionality through MCP

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 Mailcoach tools
Validating that COMPOSIO_USER_ID is also set before proceeding

Create a Tool Router session

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

const url = session.mcp.url;

What's happening:

We're creating a Tool Router session that gives your agent access to Mailcoach 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 Mailcoach tools as needed

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "mailcoach-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 Mailcoach MCP server via HTTP
The client is configured with a name and the URL from our Tool Router session
getTools() retrieves all available Mailcoach tools that the agent can use
We're creating a LangChain agent using the GPT-5 model

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 Mailcoach 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

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 Mailcoach 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: ['mailcoach']
        }
    );

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

Add Mailcoach Campaign

Tool to create a new Mailcoach campaign.

Add Email List

Tool to create a new email list.

Add suppression

Tool to add a suppression entry.

Add Tag to Email List

Tool to create a new tag within a specific email list.

Add Tags to Subscriber

Add tags to a subscriber for segmentation and targeting.

Add Transactional Email Template

Creates a new email template in Mailcoach via POST /api/templates.

Append to Subscriber Import

Tool to append CSV data to an existing subscriber import.

Confirm Subscriber

Confirm a subscriber's subscription to an email list (double opt-in confirmation).

Create Segment for Email List

Tool to create a new segment within an email list.

Create Subscriber Import

Creates a new subscriber import in Mailcoach.

Delete Campaign

Tool to delete a campaign by UUID.

Delete Email List

Tool to delete an email list by UUID.

Delete Segment from Email List

Tool to delete a segment from an email list.

Delete Subscriber

Permanently delete a subscriber by UUID from Mailcoach.

Delete Subscriber Import

Tool to delete a subscriber import by its UUID.

Delete Suppression

Tool to delete a suppression entry by UUID.

Delete Tag from Email List

Tool to delete a tag from an email list.

Delete Template

Tool to delete a template by UUID.

Delete Transactional Mail

Tool to delete a transactional mail send record by its UUID.

Get All Campaigns

Tool to retrieve all campaigns.

Get All Sent Items

Tool to retrieve all sent items.

Get All Subscriber Imports

Tool to retrieve all subscriber imports.

Get All Suppressions

Retrieve a paginated list of all email suppression entries from Mailcoach.

Get All Tags

Tool to retrieve all tags for a specific email list.

Get All Templates

Tool to retrieve all templates.

Get All Transactional Email Templates

Tool to retrieve all transactional email templates.

Get Campaign Bounces

Tool to retrieve bounced subscribers of a sent campaign with pagination support.

Get Campaign Clicks

Tool to retrieve clicks from a sent campaign with pagination support.

Get Campaign Opens

Tool to retrieve all opens for a sent campaign with pagination support.

Get Campaign Unsubscribes

Tool to retrieve unsubscribes from a sent campaign with pagination support.

Get Email Lists

Tool to retrieve all email lists.

Get Segment

Tool to retrieve details of a specific segment.

Get Specific Campaign

Tool to retrieve details of a specific Mailcoach campaign.

Get Specific Email List

Retrieve detailed information about a specific Mailcoach email list by its UUID.

Get Specific Subscriber

Tool to retrieve a specific subscriber.

Get Specific Suppression

Tool to retrieve a specific suppression entry.

Get Specific Tag

Tool to retrieve details of a specific tag.

Get Specific Template

Retrieves the full details of a specific Mailcoach email template by its UUID.

Get Subscriber Import

Tool to retrieve details of a specific subscriber import by UUID.

Get Transactional Mail

Tool to retrieve details of a specific transactional email by its UUID.

Get User

Tool to retrieve details of the currently authenticated user.

List Segments

Tool to retrieve all segments for a specific email list.

List Subscribers

Tool to list all subscribers from a specific email list with pagination support.

List Transactional Mails

Tool to retrieve all transactional email records.

Remove Tags from Subscriber

Tool to remove tags from a subscriber.

Resend Subscriber Confirmation

Tool to resend confirmation email to a subscriber.

Start Subscriber Import

Starts processing a subscriber import that is in 'draft' status.

Subscribe To Email List

Subscribe (or update) a subscriber to an email list.

Unsubscribe Subscriber

Unsubscribe a subscriber from their email list in Mailcoach.

Update Campaign

Tool to update an existing Mailcoach campaign.

Update Email List

Tool to update an existing email list.

Update Segment

Tool to update an existing segment within an email list.

Update Subscriber

Tool to update a subscriber.

Update Subscriber Import

Tool to update an existing subscriber import.

Update Tag

Tool to update an existing tag within an email list.

Update Template

Updates an existing email template in Mailcoach.

FRAMEWORKS

How to build Mailcoach MCP Agent with another framework

OpenAI Agents SDK

Use Mailcoach MCP with OpenAI Agents SDK

Claude Agent SDK

Use Mailcoach MCP with Claude Agent SDK

Claude Code

Use Mailcoach MCP with Claude Code

Claude Cowork

Use Mailcoach MCP with Claude Cowork

Codex

Use Mailcoach MCP with Codex

OpenClaw

Use Mailcoach MCP with OpenClaw

Hermes

Use Mailcoach MCP with Hermes

CLI

Use Mailcoach MCP with CLI

Google ADK

Use Mailcoach MCP with Google ADK

Vercel AI SDK

Use Mailcoach MCP with Vercel AI SDK

Mastra AI

Use Mailcoach MCP with Mastra AI

LlamaIndex

Use Mailcoach MCP with LlamaIndex

CrewAI

Use Mailcoach MCP with CrewAI

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Oauth2

Reddit is a social news platform with thriving user-driven communities (subreddits). It's the go-to place for discussion, content sharing, and viral marketing.

Facebook

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.

Oauth2

LinkedIn is a professional networking platform for connecting, sharing content, and engaging with business opportunities. It's the go-to place for building your professional brand and unlocking new career connections.

Active campaign

Api Key

ActiveCampaign is a marketing automation and CRM platform for managing email campaigns, sales pipelines, and customer segmentation. It helps businesses engage customers and drive growth through smart automation and targeted outreach.

FAQ

Frequently asked questions

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

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

Start with Mailcoach.It takes 30 seconds.

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

Start building

Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREE BOOK A DEMO

Karan skipped his own birthday party to fix our critical issue. It was 10pm and he diverted his Waymo to help us instead. This really sets the bar — it shows the commitment you need when users rely on your software.

Harsha Gaddipati

Co-founder, Slashy

A lot of students tell us that the moment their connected tools start talking to each other inside Opennote feels almost magical. The agent just knows them, and it's immensely helped keep new users on the platform.

Abhi Arya

Co-founder, Opennote

We chose Composio over Pipedream because it delivered depth where it mattered — niche tools and tricky edge cases other platforms simply ignored. That gave us confidence to scale without compromising.

Nirman Dave

CEO, Zams

As a solo builder, shipping fast is life or death. The only way I can outcompete incumbents is by outmanoeuvring them. Getting bogged down managing agent auth would have been a death sentence.

Ryan Yu

Founder, Extra Thursday

Before Composio, adding tool integrations was slow and resource-intensive. Each one could take weeks of engineering time, and maintaining them meant constantly keeping up with API changes.

Tomisin Jenrola

Founder & CEO, SwarmZero

With hands-on help from their founder, we integrated Gmail and Google Drive in just 30 minutes. This level of personal support and commitment is exactly what startups should strive for.

Jerome Leclanche

Co-Founder, Ingram Technologies

How to integrate Mailcoach MCP with LangChain

Connect Mailcoach without auth hassles

Introduction

Also integrate Mailcoach with

TL;DR

What is LangChain?

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

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

What is Composio SDK?

How the Composio SDK works

Step-by-step Guide

Prerequisites

Getting API Keys for OpenAI and Composio

Install dependencies

Set up environment variables

Import dependencies

Initialize Composio client

Create a Tool Router session

Configure the agent with the MCP URL

Set up interactive chat interface

Run the application

Complete Code

Conclusion

Supported Tools

How to build Mailcoach MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Explore Other Toolkits

Reddit

Facebook

Linkedin

Active campaign

Frequently asked questions

What are the differences in Tool Router MCP and Mailcoach MCP?+

Can I use Tool Router MCP with LangChain?+

Can I manage the permissions and scopes for Mailcoach while using Tool Router?+

How safe is my data with Composio Tool Router?+

Start with Mailcoach.It takes 30 seconds.

Teams ship real agents on Composio