# How to integrate Lemlist MCP with Vercel AI SDK v6

```json
{
  "title": "How to integrate Lemlist MCP with Vercel AI SDK v6",
  "toolkit": "Lemlist",
  "toolkit_slug": "lemlist",
  "framework": "Vercel AI SDK",
  "framework_slug": "ai-sdk",
  "url": "https://composio.dev/toolkits/lemlist/framework/ai-sdk",
  "markdown_url": "https://composio.dev/toolkits/lemlist/framework/ai-sdk.md",
  "updated_at": "2026-05-12T10:17:22.635Z"
}
```

## Introduction

This guide walks you through connecting Lemlist to Vercel AI SDK v6 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 Vercel AI 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

- [OpenAI Agents SDK](https://composio.dev/toolkits/lemlist/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/lemlist/framework/claude-agents-sdk)
- [Claude Code](https://composio.dev/toolkits/lemlist/framework/claude-code)
- [Claude Cowork](https://composio.dev/toolkits/lemlist/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/lemlist/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/lemlist/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/lemlist/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/lemlist/framework/cli)
- [Google ADK](https://composio.dev/toolkits/lemlist/framework/google-adk)
- [LangChain](https://composio.dev/toolkits/lemlist/framework/langchain)
- [Mastra AI](https://composio.dev/toolkits/lemlist/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/lemlist/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/lemlist/framework/crew-ai)

## TL;DR

Here's what you'll learn:
- How to set up and configure a Vercel AI SDK agent with Lemlist integration
- Using Composio's Tool Router to dynamically load and access Lemlist tools
- Creating an MCP client connection using HTTP transport
- Building an interactive CLI chat interface with conversation history management
- Handling tool calls and results within the Vercel AI SDK framework

## What is Vercel AI SDK?

The Vercel AI SDK is a TypeScript library for building AI-powered applications. It provides tools for creating agents that can use external services and maintain conversation state.
Key features include:
- streamText: Core function for streaming responses with real-time tool support
- MCP Client: Built-in support for Model Context Protocol via @ai-sdk/mcp
- Step Counting: Control multi-step tool execution with stopWhen: stepCountIs()
- OpenAI Provider: Native integration with OpenAI models

## 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.

## Supported Tools

| Tool slug | Name | Description |
|---|---|---|
| `LEMLIST_CREATE_COMPANY_NOTE` | Create Company Note | Tool to create a note attached to a specific company. Use when you need to add annotations or notes to a company record for tracking purposes. |
| `LEMLIST_DELETE_DELETE_SCHEDULE` | Delete Schedule | Tool to delete a specific schedule by scheduleId. Use when you need to remove a schedule permanently after confirming its ID. |
| `LEMLIST_DELETE_DELETE_UNSUBSCRIBE_EMAIL` | Delete Unsubscribed Email | Tool to delete an email from the unsubscribed list. Use when restoring a subscriber who has opted back in and you need to remove them from the suppressed contacts. |
| `LEMLIST_DELETE_UNSUBSCRIBE_LEAD_FROM_CAMPAIGN` | Unsubscribe Lead From Campaign | Tool to unsubscribe a lead from a campaign. Use when you need to stop further outreach by removing a lead from the specified campaign. |
| `LEMLIST_GET_ALL_WEBHOOKS` | Get All Webhooks | Tool to retrieve the list of all webhooks configured for the team. Use when you need to sync or audit active webhooks. |
| `LEMLIST_GET_CAMPAIGN_BY_ID` | Get Campaign By ID | Tool to retrieve a specific campaign by campaignId. Use when you need detailed campaign information by ID. |
| `LEMLIST_GET_CAMPAIGN_EXPORT_START` | Start Campaign Export | Tool to start an asynchronous export of all campaign statistics (CSV). Use when you need to initiate a CSV export for a given campaign and track its progress. |
| `LEMLIST_GET_CAMPAIGN_EXPORT_STATUS` | Get Campaign Export Status | Tool to check the status of an asynchronous campaign export. Use after starting an export to poll until done or error. |
| `LEMLIST_GET_CAMPAIGN_SEQUENCES` | Get Campaign Sequences | Tool to retrieve a list of all sequences for a campaign with steps and conditions. Use after fetching campaign to inspect its nested sequences and branching rules. |
| `LEMLIST_GET_CAMPAIGN_STATS` | Get Campaign Stats | Tool to retrieve performance statistics for a specific campaign within a date range. Use when you need campaign analytics including lead engagement, message delivery, and step-by-step performance metrics. |
| `LEMLIST_GET_COMPANIES_SCHEMA` | Get Companies Schema | Tool to retrieve the schema definition for companies in the people database. Use when you need to understand the structure, fields, and data types available for company records. |
| `LEMLIST_GET_CONTACT_MESSAGES` | Get Contact Messages | Tool to retrieve all messages exchanged with a specific contact. Use when you need to fetch conversation history for a contact by their contactId. |
| `LEMLIST_GET_DATABASE_FILTERS` | Get Database Filters | Tool to retrieve available filters for searching the people and companies database. Use when you need to discover what search criteria are available before querying the database. |
| `LEMLIST_GET_EXPORT_CAMPAIGN_LEADS` | Export Campaign Leads | Tool to export campaign leads with state filtering and choose between JSON or CSV output. Use when you need to download leads and their statuses for reporting or analysis. |
| `LEMLIST_GET_EXPORT_UNSUBSCRIBES` | Export Unsubscribes | Tool to download a CSV file containing all unsubscribed email addresses. Use when you need to export the full unsubscribes list for analysis or archival. |
| `LEMLIST_GET_GET_UNSUBSCRIBE_EMAIL` | Get Unsubscribed Email | Tool to retrieve a single unsubscribed email record. Use when you need to verify if a specific email has opted out of campaigns before re-subscribing them. |
| `LEMLIST_GET_LABEL` | Get Label | Tool to retrieve information about a specific label by its ID. Use when you need details about an inbox label. |
| `LEMLIST_GET_LIST_CAMPAIGNS` | List Campaigns | Tool to retrieve a list of campaigns for the team. Use when you need to discover campaign IDs, names, or statuses before performing operations like auditing or pausing campaigns. |
| `LEMLIST_GET_LIST_TASKS` | List Tasks | Tool to retrieve all pending tasks assigned to team members. Use when you need to view tasks by campaign, assignee, or other filters. Completed tasks are automatically excluded from results. |
| `LEMLIST_GET_LIST_TEAM_SENDERS` | List Team Senders | Tool to retrieve all team members and their associated campaigns. Use when you need to discover which team members are managing which campaigns or to understand campaign distribution across the team. |
| `LEMLIST_GET_LIST_WATCHLIST_SIGNALS` | List Watchlist Signals | Tool to retrieve paginated watchlist signals with filtering and sorting. Use when you need to fetch signals from watchlists based on type, status, date range, or specific watchlist ID. |
| `LEMLIST_GET_PEOPLE_SCHEMA` | Get People Schema | Tool to retrieve the schema definition for people in the people database. Use when you need to understand available fields and their structure before querying or importing people data. |
| `LEMLIST_GET_RETRIEVE_ACTIVITIES` | Retrieve Activities | Tool to fetch recent campaign activities. Use after authentication to retrieve activities filtered by campaignId, type, or limit. |
| `LEMLIST_GET_RETRIEVE_LEAD_BY_EMAIL` | Retrieve Lead By Email | Tool to retrieve a lead by their email address. Use when you have a lead's email to fetch complete lead details. |
| `LEMLIST_GET_RETRIEVE_UNSUBSCRIBES` | Retrieve Unsubscribes | Tool to retrieve the list of all people who are unsubscribed. Use when you need to sync or audit unsubscribed contacts across your campaigns. |
| `LEMLIST_GET_TEAM_CREDITS` | Get Team Credits | Tool to retrieve credits left in the team. Use after authenticating your session. |
| `LEMLIST_GET_TEAM_INFO` | Get Team Info | Tool to retrieve information about your team. Use after authentication to inspect current team settings, members, webhooks, and enabled features. Verify the returned teamId matches the intended workspace before passing it to campaign-creation or other write operations to avoid creating resources in the wrong account context. |
| `LEMLIST_GET_USER` | Get User | Tool to retrieve all information for a specific user by their ID. Use when you have a user ID to fetch complete user details including LinkedIn settings and connected mailboxes. |
| `LEMLIST_GET_USER_INFO` | Get User Info | Tool to retrieve all information of the authenticated user. Use after confirming a valid access token. |
| `LEMLIST_LIST_COMPANIES` | List Companies | Tool to retrieve a paginated list of all companies in your CRM. Use when you need to discover companies, search by name, or fetch company details for further operations. |
| `LEMLIST_LIST_COMPANY_NOTES` | List Company Notes | Tool to retrieve all notes associated with a specific company. Use when you need to view annotations, comments, or activities logged against a company record. |
| `LEMLIST_LIST_LABELS` | List Labels | Tool to list all labels available to your team. Use when you need to retrieve the full list of labels for inbox organization or filtering. |
| `LEMLIST_PATCH_MARK_LEAD_AS_NOT_INTERESTED_IN_CAMPAIGN` | Mark Lead as Not Interested in Campaign | Tool to mark a lead as not interested in a specific campaign. Use after confirming campaign and lead IDs to set status to not_interested. |
| `LEMLIST_PATCH_UPDATE_CAMPAIGN` | Update Campaign | Tool to update settings of a campaign. Use after fetching or creating a campaign to adjust name, stop-on behaviors, and other campaign flags. |
| `LEMLIST_PATCH_UPDATE_SCHEDULE` | Update Schedule | Tool to update an existing schedule with new parameters. Use after retrieving schedule details to adjust days, time window, and limits. |
| `LEMLIST_PATCH_UPDATE_SEQUENCE_STEP` | Update Sequence Step | Tool to update an existing step in a sequence (edit subject/message/delay/etc.) by sequenceId and stepId. Use after retrieving sequences to modify step content or timing. |
| `LEMLIST_POST_ADD_STEP_TO_SEQUENCE` | Add Step to Sequence | Tool to add a new step (email, LinkedIn, conditional, etc.) to an existing sequence. Use when building or editing campaign sequences to add outreach steps. |
| `LEMLIST_POST_ADD_UNSUBSCRIBE_EMAIL_DOMAIN` | Add Unsubscribe Email/Domain | Tool to add an email or domain to the unsubscribed list. Use when you need to globally block sending to a specific recipient or domain. |
| `LEMLIST_POST_ADD_VARIABLES_TO_LEAD` | Add Variables to Lead | Tool to add one or more variables to a lead. Use when you need to enrich a lead with custom data after its creation or retrieval. |
| `LEMLIST_POST_ASSOCIATE_SCHEDULE_WITH_CAMPAIGN` | Associate schedule with campaign | Tool to associate a schedule with a campaign. Use after confirming both campaignId and scheduleId to bind a schedule to its campaign. |
| `LEMLIST_POST_CREATE_CAMPAIGN` | Create Campaign | Tool to create a new campaign. Use after confirming the team ID. Returns campaign, sequence, and schedule IDs nested under a `data` key (e.g., `result['data']['campaignId']`). |
| `LEMLIST_POST_CREATE_LABEL` | Create Label | Tool to create a new label for inbox conversations. Use when you need to organize inbox messages with custom labels. |
| `LEMLIST_POST_CREATE_LEAD_IN_CAMPAIGN` | Create Lead In Campaign | Tool to create a lead and add it to a specific campaign. Use when you need to enroll a new lead into an outreach campaign. Supports optional deduplication and enrichment features. |
| `LEMLIST_POST_CREATE_SCHEDULE` | Create Schedule | Tool to create a new schedule for the team. Use when you need to define custom active times or delays for outreach operations. Returns a `scheduleId`; store it for association with campaigns or sequences. Avoid creating unused schedules. |
| `LEMLIST_POST_CREATE_TASK` | Create Task | Tool to create a manual task (opportunity) associated with a contact, company, or lead. Use when you need to track follow-ups or action items for outreach prospects. |
| `LEMLIST_POST_IGNORE_TASKS` | Ignore Tasks | Tool to mark one or more tasks as ignored in Lemlist. Use when you want to dismiss tasks without completing them. |
| `LEMLIST_POST_MARK_LEAD_AS_INTERESTED` | Mark Lead As Interested | Tool to mark a lead as interested in all campaigns. Use when a lead responds positively and you want to advance or personalize your outreach. |
| `LEMLIST_POST_MARK_LEAD_AS_INTERESTED_IN_CAMPAIGN` | Mark Lead As Interested In Campaign | Tool to mark a lead as interested in a specific campaign. Use after confirming the lead's positive engagement in that campaign. |
| `LEMLIST_POST_MARK_LEAD_AS_NOT_INTERESTED` | Mark Lead As Not Interested | Tool to mark a lead as not interested in all campaigns. Use when a lead explicitly declines outreach and should be paused across campaigns. |
| `LEMLIST_POST_PAUSE_CAMPAIGN` | Pause a running campaign | Tool to pause a running campaign. Use after confirming you have the correct campaign ID and that the campaign is currently running. |
| `LEMLIST_POST_PAUSE_LEAD` | Pause Lead | Tool to pause a lead in all campaigns or a specific campaign. Use when you want to temporarily halt outreach to a lead. |
| `LEMLIST_SEARCH_COMPANIES_DATABASE` | Search Companies Database | Tool to search the companies database using filters, keywords, and pagination. Use when you need to find companies based on criteria like industry, size, or keywords. Returns a paginated list of companies matching the specified filters. |
| `LEMLIST_SEARCH_PEOPLE_DATABASE` | Search People Database | Tool to search the Lemlist people database using filters, keywords, and pagination. Use when you need to find prospects based on criteria like location, job title, seniority, or company. Supports free-text search and structured filtering. |
| `LEMLIST_UPDATE_TASK` | Update Task | Tool to update an existing task including assignment, scheduling, and status. Use when modifying task details such as title, priority, due date, or completion status. |

## Supported Triggers

None listed.

## Creating MCP Server - Stand-alone vs Composio SDK

The Lemlist MCP server is an implementation of the Model Context Protocol that connects your AI agent to Lemlist. It provides structured and secure access so your agent can perform Lemlist operations on your behalf through a secure, permission-based interface.
With Composio's managed implementation, you don't have to create your own developer app. For production, if you're building an end product, we recommend using your own credentials. The managed server helps you prototype fast and go from 0-1 faster.

## Step-by-step Guide

### 1. Prerequisites

Before you begin, make sure you have:
- Node.js and npm installed
- A Composio account with API key
- An OpenAI API key

### 1. Getting API Keys for OpenAI and Composio

OpenAI API Key
- Go to the [OpenAI dashboard](https://platform.openai.com/settings/organization/api-keys) 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](https://dashboard.composio.dev?utm_source=toolkits&utm_medium=framework_docs).
- Navigate to your API settings and generate a new API key.
- Store this key securely as you'll need it for authentication.

### 2. Install required dependencies

First, install the necessary packages for your project.
What you're installing:
- @ai-sdk/openai: Vercel AI SDK's OpenAI provider
- @ai-sdk/mcp: MCP client for Vercel AI SDK
- @composio/core: Composio SDK for tool integration
- ai: Core Vercel AI SDK
- dotenv: Environment variable management
```bash
npm install @ai-sdk/openai @ai-sdk/mcp @composio/core ai dotenv
```

### 3. Set up environment variables

Create a .env file in your project root.
What's needed:
- OPENAI_API_KEY: Your OpenAI API key for GPT model access
- COMPOSIO_API_KEY: Your Composio API key for tool access
- COMPOSIO_USER_ID: A unique identifier for the user session
```bash
OPENAI_API_KEY=your_openai_api_key_here
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_user_id_here
```

### 4. Import required modules and validate environment

What's happening:
- We're importing all necessary libraries including Vercel AI SDK's OpenAI provider and Composio
- The dotenv/config import automatically loads environment variables
- The MCP client import enables connection to Composio's tool server
```typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Composio } from "@composio/core";
import * as readline from "readline";
import { streamText, type ModelMessage, stepCountIs } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!process.env.OPENAI_API_KEY) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({
  apiKey: composioAPIKey,
});
```

### 5. Create Tool Router session and initialize MCP client

What's happening:
- We're creating a Tool Router session that gives your agent access to Lemlist tools
- The create method takes the user ID and specifies which toolkits should be available
- The returned mcp object contains the URL and authentication headers needed to connect to the MCP server
- This session provides access to all Lemlist-related tools through the MCP protocol
```typescript
async function main() {
  // Create a tool router session for the user
  const session = await composio.create(composioUserID!, {
    toolkits: ["lemlist"],
  });

  const mcpUrl = session.mcp.url;
```

### 6. Connect to MCP server and retrieve tools

What's happening:
- We're creating an MCP client that connects to our Composio Tool Router session via HTTP
- The mcp.url provides the endpoint, and mcp.headers contains authentication credentials
- The type: "http" is important - Composio requires HTTP transport
- tools() retrieves all available Lemlist tools that the agent can use
```typescript
const mcpClient = await createMCPClient({
  transport: {
    type: "http",
    url: mcpUrl,
    headers: session.mcp.headers, // Authentication headers for the Composio MCP server
  },
});

const tools = await mcpClient.tools();
```

### 7. Initialize conversation and CLI interface

What's happening:
- We initialize an empty messages array to maintain conversation history
- A readline interface is created to accept user input from the command line
- Instructions are displayed to guide the user on how to interact with the agent
```typescript
let messages: ModelMessage[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log(
  "Ask any questions related to lemlist, like summarize my last 5 emails, send an email, etc... :)))\n",
);

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

rl.prompt();
```

### 8. Handle user input and stream responses with real-time tool feedback

What's happening:
- We use streamText instead of generateText to stream responses in real-time
- toolChoice: "auto" allows the model to decide when to use Lemlist tools
- stopWhen: stepCountIs(10) allows up to 10 steps for complex multi-tool operations
- onStepFinish callback displays which tools are being used in real-time
- We iterate through the text stream to create a typewriter effect as the agent responds
- The complete response is added to conversation history to maintain context
- Errors are caught and displayed with helpful retry suggestions
```typescript
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;
  }

  messages.push({ role: "user", content: trimmedInput });
  console.log("\nAgent is thinking...\n");

  try {
    const stream = streamText({
      model: openai("gpt-5"),
      messages,
      tools,
      toolChoice: "auto",
      stopWhen: stepCountIs(10),
      onStepFinish: (step) => {
        for (const toolCall of step.toolCalls) {
          console.log(`[Using tool: ${toolCall.toolName}]`);
          }
          if (step.toolCalls.length > 0) {
            console.log(""); // Add space after tool calls
          }
        },
      });

      for await (const chunk of stream.textStream) {
        process.stdout.write(chunk);
      }

      console.log("\n\n---\n");

      // Get final result for message history
      const response = await stream.response;
      if (response?.messages?.length) {
        messages.push(...response.messages);
      }
    } catch (error) {
      console.error("\nAn error occurred while talking to the agent:");
      console.error(error);
      console.log(
        "\nYou can try again or restart the app if it keeps happening.\n",
      );
    } finally {
      rl.prompt();
    }
  });

  rl.on("close", async () => {
    await mcpClient.close();
    console.log("\n👋 Session ended.");
    process.exit(0);
  });
}

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});
```

## Complete Code

```typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Composio } from "@composio/core";
import * as readline from "readline";
import { streamText, type ModelMessage, stepCountIs } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!process.env.OPENAI_API_KEY) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({
  apiKey: composioAPIKey,
});

async function main() {
  // Create a tool router session for the user
  const session = await composio.create(composioUserID!, {
    toolkits: ["lemlist"],
  });

  const mcpUrl = session.mcp.url;

  const mcpClient = await createMCPClient({
    transport: {
      type: "http",
      url: mcpUrl,
      headers: session.mcp.headers, // Authentication headers for the Composio MCP server
    },
  });

  const tools = await mcpClient.tools();

  let messages: ModelMessage[] = [];

  console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
  console.log(
    "Ask any questions related to lemlist, like summarize my last 5 emails, send an email, etc... :)))\n",
  );

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

  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;
    }

    messages.push({ role: "user", content: trimmedInput });
    console.log("\nAgent is thinking...\n");

    try {
      const stream = streamText({
        model: openai("gpt-5"),
        messages,
        tools,
        toolChoice: "auto",
        stopWhen: stepCountIs(10),
        onStepFinish: (step) => {
          for (const toolCall of step.toolCalls) {
            console.log(`[Using tool: ${toolCall.toolName}]`);
          }
          if (step.toolCalls.length > 0) {
            console.log(""); // Add space after tool calls
          }
        },
      });

      for await (const chunk of stream.textStream) {
        process.stdout.write(chunk);
      }

      console.log("\n\n---\n");

      // Get final result for message history
      const response = await stream.response;
      if (response?.messages?.length) {
        messages.push(...response.messages);
      }
    } catch (error) {
      console.error("\nAn error occurred while talking to the agent:");
      console.error(error);
      console.log(
        "\nYou can try again or restart the app if it keeps happening.\n",
      );
    } finally {
      rl.prompt();
    }
  });

  rl.on("close", async () => {
    await mcpClient.close();
    console.log("\n👋 Session ended.");
    process.exit(0);
  });
}

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});
```

## Conclusion

You've successfully built a Lemlist agent using the Vercel AI SDK with streaming capabilities! This implementation provides a powerful foundation for building AI applications with natural language interfaces and real-time feedback.
Key features of this implementation:
- Real-time streaming responses for a better user experience with typewriter effect
- Live tool execution feedback showing which tools are being used as the agent works
- Dynamic tool loading through Composio's Tool Router with secure authentication
- Multi-step tool execution with configurable step limits (up to 10 steps)
- Comprehensive error handling for robust agent execution
- Conversation history maintenance for context-aware responses
You can extend this further by adding custom error handling, implementing specific business logic, or integrating additional Composio toolkits to create multi-app workflows.

## How to build Lemlist MCP Agent with another framework

- [OpenAI Agents SDK](https://composio.dev/toolkits/lemlist/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/lemlist/framework/claude-agents-sdk)
- [Claude Code](https://composio.dev/toolkits/lemlist/framework/claude-code)
- [Claude Cowork](https://composio.dev/toolkits/lemlist/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/lemlist/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/lemlist/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/lemlist/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/lemlist/framework/cli)
- [Google ADK](https://composio.dev/toolkits/lemlist/framework/google-adk)
- [LangChain](https://composio.dev/toolkits/lemlist/framework/langchain)
- [Mastra AI](https://composio.dev/toolkits/lemlist/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/lemlist/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/lemlist/framework/crew-ai)

## Related Toolkits

- [Aeroleads](https://composio.dev/toolkits/aeroleads) - Aeroleads is a B2B lead generation platform for finding business emails and phone numbers. Grow your sales pipeline faster with powerful prospecting tools.
- [Autobound](https://composio.dev/toolkits/autobound) - Autobound is an AI-powered sales engagement platform that crafts hyper-personalized outreach and insights. It helps sales teams boost response rates and close more deals through tailored content and recommendations.
- [Better proposals](https://composio.dev/toolkits/better_proposals) - Better Proposals is a web-based tool for crafting and sending professional proposals. It helps teams impress clients and close deals faster with slick, easy-to-use templates.
- [Bidsketch](https://composio.dev/toolkits/bidsketch) - Bidsketch is a proposal software that helps businesses create professional proposals quickly and efficiently. It streamlines the proposal process, saving time while boosting client win rates.
- [Bolna](https://composio.dev/toolkits/bolna) - Bolna is an AI platform for building conversational voice agents. It helps businesses automate support and streamline interactions through natural, voice-powered conversations.
- [Botsonic](https://composio.dev/toolkits/botsonic) - Botsonic is a no-code AI chatbot builder for easily creating and deploying chatbots to your website. It empowers businesses to offer conversational experiences without writing code.
- [Botstar](https://composio.dev/toolkits/botstar) - BotStar is a comprehensive chatbot platform for designing, developing, and training chatbots visually on Messenger and websites. It helps businesses automate conversations and customer interactions without coding.
- [Callerapi](https://composio.dev/toolkits/callerapi) - CallerAPI is a white-label caller identification platform for branded caller ID and fraud prevention. It helps businesses boost customer trust while stopping spam, fraud, and robocalls.
- [Callingly](https://composio.dev/toolkits/callingly) - Callingly is a lead response management platform that automates immediate call and text follow-ups with new leads. It helps sales teams boost response speed and close more deals by connecting seamlessly with CRMs and lead sources.
- [Callpage](https://composio.dev/toolkits/callpage) - Callpage is a lead capture platform that lets businesses instantly connect with website visitors via callback. It boosts lead generation and increases your sales conversion rates.
- [Clearout](https://composio.dev/toolkits/clearout) - Clearout is an AI-powered service for verifying, finding, and enriching email addresses. It boosts deliverability and helps you discover high-quality leads effortlessly.
- [Clientary](https://composio.dev/toolkits/clientary) - Clientary is a platform for managing clients, invoices, projects, proposals, and more. It streamlines client work and saves you serious admin time.
- [Convolo ai](https://composio.dev/toolkits/convolo_ai) - Convolo ai is an AI-powered communications platform for sales teams. It accelerates lead response and improves conversion rates by automating calls and integrating workflows.
- [Delighted](https://composio.dev/toolkits/delighted) - Delighted is a customer feedback platform based on the Net Promoter System®. It helps you quickly gather, track, and act on customer sentiment.
- [Docsbot ai](https://composio.dev/toolkits/docsbot_ai) - Docsbot ai is a platform that lets you build custom AI chatbots trained on your documentation. It automates customer support and content generation, saving time and improving response quality.
- [Emelia](https://composio.dev/toolkits/emelia) - Emelia is an all-in-one B2B prospecting platform for cold-email, LinkedIn outreach, and prospect research. It streamlines outbound campaigns so you can find, engage, and warm up leads faster.
- [Findymail](https://composio.dev/toolkits/findymail) - Findymail is a B2B data provider offering verified email and phone contacts for sales prospecting. Enhance outreach with automated exports, email verification, and CRM enrichment.
- [Freshdesk](https://composio.dev/toolkits/freshdesk) - Freshdesk is customer support software with ticketing and automation tools. It helps teams streamline helpdesk operations for faster, better customer support.
- [Fullenrich](https://composio.dev/toolkits/fullenrich) - FullEnrich is a B2B contact enrichment platform that aggregates emails and phone numbers from 15+ data vendors. Instantly find and verify lead contact data to boost your outreach.
- [Gatherup](https://composio.dev/toolkits/gatherup) - GatherUp is a customer feedback and online review management platform. It helps businesses boost their reputation by streamlining how they collect and manage customer feedback.

## Frequently Asked Questions

### What are the differences in Tool Router MCP and Lemlist MCP?

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.

### Can I use Tool Router MCP with Vercel AI SDK v6?

Yes, you can. Vercel AI SDK v6 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.

### Can I manage the permissions and scopes for Lemlist while using Tool Router?

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.

### How safe is my data with Composio Tool Router?

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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[See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)