How to integrate Lemlist MCP with Claude Agent SDK

This guide walks you through connecting Lemlist to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Lemlist agent that can export all leads from current campaign, download list of unsubscribed emails, unsubscribe specific lead from a campaign through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a Lemlist account through Composio's Lemlist MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Lemlist is a multichannel prospecting platform for outreach via email, LinkedIn, and calls. It streamlines lead generation and boosts reply rates with personalized, automated workflows.

54 Tools

Introduction

This guide walks you through connecting Lemlist to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Lemlist agent that can export all leads from current campaign, download list of unsubscribed emails, unsubscribe specific lead from a campaign through natural language commands.

This guide will help you understand how to give your Claude Agent SDK agent real control over a Lemlist account through Composio's Lemlist MCP server.

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

Also integrate Lemlist with

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TL;DR

Here's what you'll learn:
  • Get and set up your Claude/Anthropic and Composio API keys
  • Install the necessary dependencies
  • Initialize Composio and create a Tool Router session for Lemlist
  • Configure an AI agent that can use Lemlist as a tool
  • Run a live chat session where you can ask the agent to perform Lemlist operations

What is Claude Agent SDK?

The Claude Agent SDK is Anthropic's official framework for building AI agents powered by Claude. It provides a streamlined interface for creating agents with MCP tool support and conversation management.

Key features include:

  • Native MCP Support: Built-in support for Model Context Protocol servers
  • Permission Modes: Control tool execution permissions
  • Streaming Responses: Real-time response streaming for interactive applications
  • Context Manager: Clean async context management for sessions

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

The Lemlist MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Lemlist account. It provides structured and secure access to your outreach campaigns, so your agent can manage leads, automate campaign exports, monitor unsubscribe lists, and orchestrate multichannel engagement on your behalf.

  • Automated campaign management: Retrieve campaign details by ID, audit campaign sequences, and start or monitor campaign exports for streamlined reporting and analytics.
  • Lead and subscriber control: Unsubscribe leads from campaigns, delete unsubscribed emails, or export detailed lists of campaign leads to keep your outreach data fresh and compliant.
  • Outreach data exports: Initiate and track asynchronous exports of campaign statistics or download CSVs of unsubscribed contacts for deeper insights and record-keeping.
  • Webhook administration: Fetch all configured webhooks to sync Lemlist with your other tools or audit integration points for better workflow automation.
  • Schedule management: Permanently delete schedules you no longer need, ensuring your campaigns stay organized and up to date.

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 step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • Composio API Key and Claude/Anthropic API Key
  • Primary know-how of Claude Agents SDK
  • A Lemlist account
  • Some knowledge of Python
2

Getting API Keys for Claude/Anthropic and Composio

Claude/Anthropic API Key
  • Go to the Anthropic Console and create an API key. You'll need credits to use the models.
  • 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 @anthropic-ai/claude-agent-sdk @composio/core dotenv

Install the Composio SDK and the Claude Agents SDK.

What's happening:

  • @composio/core provides Composio integration for Anthropic
  • @anthropic-ai/claude-agent-sdk is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
ANTHROPIC_API_KEY=your_anthropic_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates with Composio
  • USER_ID identifies the user for session management
  • ANTHROPIC_API_KEY authenticates with Anthropic/Claude
5

Import dependencies

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

dotenv.config();
What's happening:
  • We're importing all necessary libraries including the Claude Agent SDK and Composio
  • The dotenv.config() function loads environment variables from your .env file
  • This setup prepares the foundation for connecting Claude with Lemlist functionality
6

Create a Composio instance and Tool Router session

async function chat() {
  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 composio = new Composio({ apiKey: COMPOSIO_API_KEY });

  // Create Tool Router session for Lemlist
  const session = await composio.create(USER_ID, {
    toolkits: ['lemlist'],
  });
  const mcpUrl = session?.mcp.url;
What's happening:
  • The function checks for the required COMPOSIO_API_KEY environment variable
  • We're creating a Composio instance using our API key
  • The create method creates a Tool Router session for Lemlist
  • The returned url is the MCP server URL that your agent will use
7

Configure Claude Agent with MCP

const options: Options = {
  permissionMode: 'bypassPermissions',
  mcpServers: {
    composio: {
      type: 'http',
      url: mcpUrl,
      headers: { 'x-api-key': COMPOSIO_API_KEY }
    }
  },
  systemPrompt: 'You are a helpful assistant with access to Lemlist tools via Composio.',
  maxTurns: 10,
};
What's happening:
  • We're configuring the Claude Agent options with the MCP server URL
  • permissionMode: 'bypassPermissions' allows the agent to execute operations without asking for permission each time
  • The system prompt instructs the agent that it has access to Lemlist
  • maxTurns: 10 limits the conversation length to prevent excessive API usage
8

Create client and start chat loop

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}
What's happening:
  • The readline interface is created to handle user input and output
  • The query function is used to send the user's input to the agent
  • The chat loop continues until the user types 'exit' or 'quit'
9

Run the application

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}
What's happening:
  • The chat function is the entry point for the application
  • The try-catch block is used to handle any errors that occur

Complete Code

Here's the complete code to get you started with Lemlist and Claude Agent SDK:

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

async function chat() {
  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 composio = new Composio({ apiKey: COMPOSIO_API_KEY });
  const session = await composio.create(USER_ID, {
    toolkits: ['lemlist']
  });
  const mcp_url = session?.mcp.url;

  const options: Options = {
    permissionMode: 'bypassPermissions',
    mcpServers: {
      composio: {
        type: 'http',
        url: mcp_url,
        headers: { 'x-api-key': COMPOSIO_API_KEY }
      }
    },
    systemPrompt: 'You are a helpful assistant with access to Lemlist tools via Composio.',
    maxTurns: 10,
  };

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}

Conclusion

You've successfully built a Claude Agent SDK agent that can interact with Lemlist through Composio's Tool Router.

Key features:

  • Native MCP support through Claude's agent framework
  • Streaming responses for real-time interaction
  • Permission bypass for smooth automated workflows
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS

Supported Tools

Every Lemlist action and event your agent gets out of the box.

Create Company Note

Tool to create a note attached to a specific company.

Delete Schedule

Tool to delete a specific schedule by scheduleId.

Delete Unsubscribed Email

Tool to delete an email from the unsubscribed list.

Unsubscribe Lead From Campaign

Tool to unsubscribe a lead from a campaign.

Get All Webhooks

Tool to retrieve the list of all webhooks configured for the team.

Get Campaign By ID

Tool to retrieve a specific campaign by campaignId.

Start Campaign Export

Tool to start an asynchronous export of all campaign statistics (CSV).

Get Campaign Export Status

Tool to check the status of an asynchronous campaign export.

Get Campaign Sequences

Tool to retrieve a list of all sequences for a campaign with steps and conditions.

Get Campaign Stats

Tool to retrieve performance statistics for a specific campaign within a date range.

Get Companies Schema

Tool to retrieve the schema definition for companies in the people database.

Get Contact Messages

Tool to retrieve all messages exchanged with a specific contact.

Get Database Filters

Tool to retrieve available filters for searching the people and companies database.

Export Campaign Leads

Tool to export campaign leads with state filtering and choose between JSON or CSV output.

Export Unsubscribes

Tool to download a CSV file containing all unsubscribed email addresses.

Get Unsubscribed Email

Tool to retrieve a single unsubscribed email record.

Get Label

Tool to retrieve information about a specific label by its ID.

List Campaigns

Tool to retrieve a list of campaigns for the team.

List Tasks

Tool to retrieve all pending tasks assigned to team members.

List Team Senders

Tool to retrieve all team members and their associated campaigns.

List Watchlist Signals

Tool to retrieve paginated watchlist signals with filtering and sorting.

Get People Schema

Tool to retrieve the schema definition for people in the people database.

Retrieve Activities

Tool to fetch recent campaign activities.

Retrieve Lead By Email

Tool to retrieve a lead by their email address.

Retrieve Unsubscribes

Tool to retrieve the list of all people who are unsubscribed.

Get Team Credits

Tool to retrieve credits left in the team.

Get Team Info

Tool to retrieve information about your team.

Get User

Tool to retrieve all information for a specific user by their ID.

Get User Info

Tool to retrieve all information of the authenticated user.

List Companies

Tool to retrieve a paginated list of all companies in your CRM.

List Company Notes

Tool to retrieve all notes associated with a specific company.

List Labels

Tool to list all labels available to your team.

Mark Lead as Not Interested in Campaign

Tool to mark a lead as not interested in a specific campaign.

Update Campaign

Tool to update settings of a campaign.

Update Schedule

Tool to update an existing schedule with new parameters.

Update Sequence Step

Tool to update an existing step in a sequence (edit subject/message/delay/etc.

Add Step to Sequence

Tool to add a new step (email, LinkedIn, conditional, etc.

Add Unsubscribe Email/Domain

Tool to add an email or domain to the unsubscribed list.

Add Variables to Lead

Tool to add one or more variables to a lead.

Associate schedule with campaign

Tool to associate a schedule with a campaign.

Create Campaign

Tool to create a new campaign.

Create Label

Tool to create a new label for inbox conversations.

Create Lead In Campaign

Tool to create a lead and add it to a specific campaign.

Create Schedule

Tool to create a new schedule for the team.

Create Task

Tool to create a manual task (opportunity) associated with a contact, company, or lead.

Ignore Tasks

Tool to mark one or more tasks as ignored in Lemlist.

Mark Lead As Interested

Tool to mark a lead as interested in all campaigns.

Mark Lead As Interested In Campaign

Tool to mark a lead as interested in a specific campaign.

Mark Lead As Not Interested

Tool to mark a lead as not interested in all campaigns.

Pause a running campaign

Tool to pause a running campaign.

Pause Lead

Tool to pause a lead in all campaigns or a specific campaign.

Search Companies Database

Tool to search the companies database using filters, keywords, and pagination.

Search People Database

Tool to search the Lemlist people database using filters, keywords, and pagination.

Update Task

Tool to update an existing task including assignment, scheduling, and status.

FRAMEWORKS

How to build Lemlist MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Lemlist MCP with OpenAI Agents SDK

Claude Code logo

Claude Code

Use Lemlist MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Lemlist MCP with Claude Cowork

Codex logo

Codex

Use Lemlist MCP with Codex

OpenClaw logo

OpenClaw

Use Lemlist MCP with OpenClaw

Hermes logo

Hermes

Use Lemlist MCP with Hermes

CLI logo

CLI

Use Lemlist MCP with CLI

Google ADK logo

Google ADK

Use Lemlist MCP with Google ADK

LangChain logo

LangChain

Use Lemlist MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Lemlist MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Lemlist MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Lemlist MCP with LlamaIndex

CrewAI logo

CrewAI

Use Lemlist MCP with CrewAI

FAQ

Frequently asked questions

With a standalone Lemlist MCP server, the agents and LLMs can only access a fixed set of Lemlist tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Lemlist and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Claude Agent SDK 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 Lemlist tools.

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

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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.

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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.

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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.

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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.

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