How to integrate Nutshell MCP with LangChain

Connect LangChain to Nutshell MCP. List all open deals in the current pipeline, add a new contact with name and email, and more using natural language, with authentication handled for you.

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Nutshell

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Nutshell is a flexible CRM and email marketing platform for small businesses. It helps manage contacts, sales pipelines, and customer relationships efficiently.

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Introduction

This guide walks you through connecting Nutshell to LangChain using the Composio tool router. By the end, you'll have a working Nutshell agent that can list all open deals in the current pipeline, add a new contact with name and email, update the status of deal 'acme corp' to won through natural language commands.

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

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

Also integrate Nutshell with

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

TL;DR

Here's what you'll learn:

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

The Nutshell MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Nutshell account. It provides structured and secure access to your accounts, contacts, leads, and sales records, so your agent can create accounts, add contacts, manage leads, retrieve customer details, and update sales information on your behalf.

Account creation and lookup: Have your agent create company accounts and retrieve existing account details when you need customer context.
Contact management: Let the agent add new contacts, review your contact list, retrieve specific contact details, and update existing records.
Lead creation: Direct your agent to create new leads in Nutshell as prospects enter your sales pipeline.
Lead review and updates: Instruct your agent to list leads, retrieve specific lead details, and update records as sales conversations progress.
Sales record maintenance: Have your agent keep account, contact, and lead information current as customer relationships develop.

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 Nutshell 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 Nutshell 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: ['nutshell']
    }
);

const url = session.mcp.url;

What's happening:

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

Configure the agent with the MCP URL

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

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

Create Accounts

Tool to create one or more accounts in Nutshell.

Create Custom Field for Accounts

Tool to create a custom field for accounts in Nutshell.

Create Activities

Tool to create one or more activities in Nutshell CRM.

Create Contacts

Tool to create one or more contacts in Nutshell CRM.

Create Lead

Tool to create a lead in Nutshell CRM using the JSON-RPC API.

Create Custom Field for Leads

Tool to create a custom field for leads in Nutshell.

Create Notes

Tool to create a note in Nutshell.

Create Sources

Tool to create new sources in Nutshell CRM.

Create Tags

Tool to create one or more tags in Nutshell.

Delete Account

Tool to delete an account from Nutshell.

Delete Contact

Tool to delete a contact by ID.

Delete Lead

Tool to delete a lead from Nutshell CRM.

Delete Note

Tool to delete a note from Nutshell CRM.

Delete Product Map

Tool to delete a product on a lead.

Delete Task

Tool to delete a task from Nutshell CRM.

Edit Nutshell Account

Tool to edit an existing account in Nutshell CRM.

Get Account

Tool to retrieve an account from Nutshell.

Get Account Custom Fields

Tool to retrieve custom fields for a specific account in Nutshell.

Get Activity

Tool to retrieve a single activity by ID from Nutshell CRM.

Get Contact

Tool to retrieve a specific contact by ID from Nutshell CRM.

Get Contact Custom Fields

Tool to retrieve custom fields for a specific contact in Nutshell.

Get Lead

Tool to retrieve a specific lead by ID from Nutshell CRM.

Get Lead's Custom Fields

Tool to retrieve custom fields for a specific lead in Nutshell CRM.

Get Note

Tool to retrieve a single note by ID from Nutshell CRM.

Get Product Category

Tool to retrieve a single product category by ID from Nutshell CRM.

Get Task

Tool to retrieve a single task by ID from Nutshell CRM.

List Account Custom Field Attributes

Tool to retrieve all account custom field attributes from Nutshell CRM.

List Account Fields

Tool to retrieve all available fields for accounts in Nutshell.

List Accounts

Tool to retrieve list items for all accounts in Nutshell CRM.

List Account Types

Tool to retrieve a list of all account types from Nutshell CRM.

List Activities

Tool to retrieve a list of activities from Nutshell CRM.

List Activity Types

Tool to retrieve a list of all activity types from Nutshell CRM.

List Competitor Maps

Tool to get a list of lead-competitor relationships from Nutshell CRM.

List Competitors

Tool to get a list of competitors from Nutshell CRM.

List Contacts

Tool to get a list of contacts from Nutshell CRM.

List Contact Custom Field Attributes

Tool to retrieve all available custom field attributes for contacts in Nutshell.

List Contact Fields

Tool to retrieve all available fields for contacts in Nutshell.

List Contacts

Tool to retrieve list items for all contacts in Nutshell CRM.

List Deleted Events

Tool to get a feed of deletion events from Nutshell CRM.

List Editions

Tool to retrieve a list of all editions from Nutshell CRM.

List Events

Tool to get a list of events from Nutshell CRM.

List Filters

Tool to get saved filters from Nutshell CRM.

List Forms

Tool to get all forms from Nutshell.

List Industries

Tool to retrieve a list of all industries from Nutshell CRM.

List Invoices

Tool to get a list of invoices from Nutshell CRM.

List Leads

Tool to get a list of leads from Nutshell CRM.

List Lead Custom Field Attributes

Tool to retrieve all applicable custom field attributes for leads in Nutshell CRM.

List Lead Fields

Tool to retrieve all available fields for leads in Nutshell.

List Leads

Tool to retrieve list items for all leads in Nutshell CRM.

Get Leads Report

Tool to get reports for leads from Nutshell CRM.

List Lead Stages

Tool to retrieve all stages associated with a specific lead in Nutshell CRM.

List Markets

Tool to retrieve a list of all markets from Nutshell CRM.

List Notes

Tool to get a list of notes from Nutshell CRM.

List Lead Outcomes

Tool to retrieve a list of lead outcomes from Nutshell CRM.

List Product Categories

Tool to get a list of all product categories from Nutshell CRM.

List Product Maps

Tool to get a list of lead products from Nutshell CRM.

List Products

Tool to get a list of products from Nutshell CRM.

List Quotes

Tool to get a list of quotes from Nutshell CRM.

List Sources

Tool to retrieve a list of sources from Nutshell CRM.

List Stages

Tool to retrieve a list of all stages from Nutshell CRM.

List Pipelines

Tool to retrieve a list of all pipelines (stagesets) from Nutshell CRM.

List Tags

Tool to retrieve a list of tags from Nutshell CRM.

List Territories

Tool to retrieve a list of all territories from Nutshell CRM.

List Users

Tool to get a list of all users from Nutshell CRM.

Reopen Lead

Tool to reopen a lead in Nutshell CRM.

Set Lead Pipeline

Tool to set the pipeline (stageset) for a lead in Nutshell CRM.

Undelete Account

Tool to undelete a previously deleted account in Nutshell.

Undelete Contact

Tool to undelete a previously deleted contact in Nutshell CRM.

Undelete Lead

Tool to undelete a previously deleted lead from Nutshell CRM.

Undelete Note

Tool to undelete a previously deleted note in Nutshell CRM.

Undelete Source

Tool to undelete a source by ID.

Undelete Tag

Tool to undelete a previously deleted tag in Nutshell.

Update Account with JSON Patch

Tool to update an account in Nutshell using JSON Patch operations.

Update Nutshell Contact

Tool to update a contact using JSON Patch operations.

Update Lead

Tool to update a lead in Nutshell CRM using JSON Patch operations.

Update Lead Status

Tool to update the status of a lead in Nutshell CRM.

Update Task with JSON Patch

Tool to update a task in Nutshell using JSON Patch operations.

Watch Lead

Tool to watch a lead in Nutshell CRM.

FRAMEWORKS

How to build Nutshell MCP Agent with another framework

Claude Code

Use Nutshell MCP with Claude Code

Claude Cowork

Use Nutshell MCP with Claude Cowork

OpenAI Agents SDK

Use Nutshell MCP with OpenAI Agents SDK

Claude Agent SDK

Use Nutshell MCP with Claude Agent SDK

Codex

Use Nutshell MCP with Codex

OpenClaw

Use Nutshell MCP with OpenClaw

Hermes

Use Nutshell MCP with Hermes

Atomic Agent

Use Nutshell MCP with Atomic Agent

Google ADK

Use Nutshell MCP with Google ADK

Vercel AI SDK

Use Nutshell MCP with Vercel AI SDK

Mastra AI

Use Nutshell MCP with Mastra AI

LlamaIndex

Use Nutshell MCP with LlamaIndex

CrewAI

Use Nutshell MCP with CrewAI

Pydantic AI

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AutoGen

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MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

HubSpot

Oauth2Api Key

HubSpot is an all-in-one marketing, sales, and customer service platform. It lets teams nurture leads, automate outreach, and track every customer interaction in one place.

Pipedrive

Oauth2Api Key

Pipedrive is a sales management platform offering pipeline visualization, lead tracking, and workflow automation. It helps sales teams keep deals moving forward efficiently and never miss a follow-up.

Salesforce

Oauth2S2s Oauth2

Salesforce is a leading CRM platform that helps businesses manage sales, service, and marketing. It centralizes customer data, enabling teams to drive growth and build strong relationships.

Apollo

Api Key

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.

FAQ

Frequently asked questions

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

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

Start with Nutshell.It takes 30 seconds.

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How to integrate Nutshell MCP with LangChain

Connect Nutshell without auth hassles

Introduction

Also integrate Nutshell with

TL;DR

What is LangChain?

What is the Nutshell 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 Nutshell MCP Agent with another framework

Claude Code

Claude Cowork

OpenAI Agents SDK

Claude Agent SDK

Codex

OpenClaw

Hermes

Atomic Agent

Google ADK

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Pydantic AI

AutoGen

Explore Other Toolkits

HubSpot

Pipedrive

Salesforce

Apollo

Frequently asked questions

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

Can I use Tool Router MCP with LangChain?+

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

How safe is my data with Composio Tool Router?+

Start with Nutshell.It takes 30 seconds.