How to integrate Nutshell MCP with Claude Code

Connect Claude Code 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.

Nutshell logoNutshell
Basic

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

78 Tools

Introduction

Manage your Nutshell directly from Claude Code with zero worries about OAuth hassles, API-breaking issues, or reliability and security concerns.

You can do this in two different ways:

  1. Via Composio Connect - Direct and easiest approach
  2. Via Composio SDK - Programmatic approach with more control

Also integrate Nutshell with

Why use Composio?

  • Only one MCP URL to connect multiple apps with Claude Code with zero auth hassles.
  • Programmatic tool calling allows LLMs to write its code in a remote workbench to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
  • Handling Large tool responses out of LLM context to minimize context rot.
  • Dynamic just-in-time access to 20,000 tools across 1500+ other Apps for cross-app workflows. It loads the tools you need, so LLMs aren't overwhelmed by tools you don't need.

Connecting Nutshell to Claude Code using Composio

1. Add the Composio MCP to Claude

Terminal

2. Start Claude Code

bash
claude

3. Open your MCP list

bash
/mcp

4. Select Composio and click on Authenticate

Select Composio and click Authenticate

5. This will redirect you to the Composio OAuth page. Complete the flow by authorizing Composio and you're all set.

Composio OAuth authorization page
Composio authorization complete
Ask Claude to connect to your account and authenticate via the link

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.

Connecting Nutshell via Composio SDK

Composio SDK is the underlying technology that powers these integrations. It provides a universal gateway with full programmatic control. You can programmatically generate an MCP URL with the app you need (here Nutshell) for even more tool search precision. It's secure and reliable.

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, make sure you have:
  • Claude Pro, Max, or API billing enabled Anthropic account
  • Composio API Key
  • A Nutshell account
  • Basic knowledge of Python or TypeScript
2

Install Claude Code

bash
# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

# Windows CMD
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd

To install Claude Code, use one of the following methods based on your operating system:

3

Set up Claude Code

bash
cd your-project-folder
claude

Open a terminal, go to your project folder, and start Claude Code:

  • Claude Code will open in your terminal
  • Follow the prompts to sign in with your Anthropic account
  • Complete the authentication flow
  • Once authenticated, you can start using Claude Code
Claude Code initial setup showing sign-in prompt
Claude Code terminal after successful login
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here

Create a .env file in your project root with the following variables:

  • COMPOSIO_API_KEY authenticates with Composio (get it from Composio dashboard)
  • USER_ID identifies the user for session management (use any unique identifier)
5

Install Composio library

npm install @composio/core dotenv

Install the Composio TypeScript library to create MCP sessions.

  • @composio/core provides the core Composio functionality
  • dotenv loads environment variables from your .env file
6

Generate Composio MCP URL

import 'dotenv/config';
import { Composio } from '@composio/core';

const { COMPOSIO_API_KEY, USER_ID } = process.env;

if (!COMPOSIO_API_KEY || !USER_ID) {
  throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
}

const composioClient = new Composio({ apiKey: COMPOSIO_API_KEY });

const composioSession = await composioClient.create(USER_ID, {
  toolkits: ['nutshell'],
});

const composioMcpUrl = composioSession?.mcp.url;

console.log(`MCP URL: ${composioMcpUrl}`);
console.log(`\nUse this command to add to Claude Code:`);
console.log(`claude mcp add --transport http nutshell-composio "${composioMcpUrl}" --headers "X-API-Key:${COMPOSIO_API_KEY}"`);

Create a script to generate a Composio MCP URL for Nutshell. This URL will be used to connect Claude Code to Nutshell.

What's happening

  • We import the Composio client and load environment variables
  • Create a Composio instance with your API key
  • Call create() to create a Tool Router session for Nutshell
  • The returned mcp.url is the MCP server URL that Claude Code will use
  • The script prints this URL so you can copy it
7

Run the script and copy the MCP URL

node --loader ts-node/esm generate_mcp_url.ts
# or if using tsx
tsx generate_mcp_url.ts

Run your TypeScript script to generate the MCP URL.

  • The script connects to Composio and creates a Tool Router session
  • It prints the MCP URL and the exact command you need to run
  • Copy the entire claude mcp add command from the output
8

Add Nutshell MCP to Claude Code

bash
claude mcp add --transport http nutshell-composio "YOUR_MCP_URL_HERE" --headers "X-API-Key:YOUR_COMPOSIO_API_KEY"

# Then restart Claude Code
exit
claude

In your terminal, add the MCP server using the command from the previous step. The command format is:

  • claude mcp add registers a new MCP server with Claude Code
  • --transport http specifies that this is an HTTP-based MCP server
  • The server name (nutshell-composio) is how you'll reference it
  • The URL points to your Composio Tool Router session
  • --headers includes your Composio API key for authentication

After running the command, close the current Claude Code session and start a new one for the changes to take effect.

9

Verify the installation

bash
claude mcp list

Check that your Nutshell MCP server is properly configured.

  • This command lists all MCP servers registered with Claude Code
  • You should see your nutshell-composio entry in the list
  • This confirms that Claude Code can now access Nutshell tools

If everything is wired up, you should see your nutshell-composio entry listed:

Claude Code MCP list showing the toolkit MCP server
10

Authenticate Nutshell

The first time you try to use Nutshell tools, you'll be prompted to authenticate.

  • Claude Code will detect that you need to authenticate with Nutshell
  • It will show you an authentication link
  • Open the link in your browser (or copy/paste it)
  • Complete the Nutshell authorization flow
  • Return to the terminal and start using Nutshell through Claude Code

Once authenticated, you can ask Claude Code to perform Nutshell operations in natural language. For example:

  • "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."

Complete Code

Here's the complete code to get you started with Nutshell and Claude Code:

import 'dotenv/config';
import { Composio } from '@composio/core';

const { COMPOSIO_API_KEY, USER_ID } = process.env;

if (!COMPOSIO_API_KEY || !USER_ID) {
  throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
}

const composioClient = new Composio({ apiKey: COMPOSIO_API_KEY });

const composioSession = await composioClient.create(USER_ID, {
  toolkits: ['nutshell'],
});

const composioMcpUrl = composioSession?.mcp.url;

console.log(`MCP URL: ${composioMcpUrl}`);
console.log(`\nUse this command to add to Claude Code:`);
console.log(`claude mcp add --transport http nutshell-composio "${composioMcpUrl}" --headers "X-API-Key:${COMPOSIO_API_KEY}"`);

Conclusion

You've successfully integrated Nutshell with Claude Code using Composio's MCP server. Now you can interact with Nutshell directly from your terminal using natural language commands.

Key features of this setup:

  • Terminal-native experience without switching contexts
  • Natural language commands for Nutshell operations
  • Secure authentication through Composio's managed MCP
  • Tool Router for dynamic tool discovery and execution

Next steps:

  • Try asking Claude Code to perform various Nutshell operations
  • Add more toolkits to your Tool Router session for multi-app workflows
  • Integrate this setup into your development workflow for increased productivity

You can extend this by adding more toolkits, implementing custom workflows, or building automation scripts that leverage Claude Code's capabilities.

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.

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. Claude Code 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.

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