How to integrate Instantly MCP with Mastra AI

BOOK A CALLGET STARTED FOR FREE
Framework Integration Gradient
Instantly Logo
Mastra AI Logo
divider

Introduction

This guide walks you through connecting Instantly to Mastra AI using the Composio tool router. By the end, you'll have a working Instantly agent that can create a new cold email campaign, add a new lead to my campaign, check unread emails in my inbox, run an inbox placement test for gmail through natural language commands.

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

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

TL;DR

Here's what you'll learn:
  • Set up your environment so Mastra, OpenAI, and Composio work together
  • Create a Tool Router session in Composio that exposes Instantly tools
  • Connect Mastra's MCP client to the Composio generated MCP URL
  • Fetch Instantly tool definitions and attach them as a toolset
  • Build a Mastra agent that can reason, call tools, and return structured results
  • Run an interactive CLI where you can chat with your Instantly agent

What is Mastra AI?

Mastra AI is a TypeScript framework for building AI agents with tool support. It provides a clean API for creating agents that can use external services through MCP.

Key features include:

  • MCP Client: Built-in support for Model Context Protocol servers
  • Toolsets: Organize tools into logical groups
  • Step Callbacks: Monitor and debug agent execution
  • OpenAI Integration: Works with OpenAI models via @ai-sdk/openai

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

The Instantly MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Instantly account. It provides structured and secure access to your campaigns, leads, and outreach tools, so your agent can perform actions like launching new campaigns, managing leads, tracking inbox statistics, and handling API credentials on your behalf.

  • Automated campaign creation and management: Ask your agent to launch new cold email campaigns or update existing ones, streamlining your outreach workflow without manual setup.
  • Lead and lead list management: Let your agent add new leads, organize them into lists, or enrich them with AI-driven insights to maximize your campaign effectiveness.
  • Email verification and deliverability tracking: Direct your agent to check the verification status of email addresses or run inbox placement tests to monitor and improve deliverability across providers.
  • Inbox activity monitoring: Fetch unread email counts or campaign engagement metrics, helping you stay on top of your outreach performance in real time.
  • API key and webhook automation: Have your agent create or delete API keys for secure integrations, or set up webhooks to receive instant notifications about important Instantly events.

Supported Tools & Triggers

Tools
Check Email Verification StatusTool to check status of an email verification job.
Count Unread EmailsTool to retrieve the count of unread emails.
Create AI EnrichmentTool to create an AI enrichment job for a campaign or lead list.
Create API KeyTool to create a new API key.
Create CampaignTool to create a new campaign.
Create Inbox Placement TestTool to create an inbox placement test.
Create LeadTool to create a new lead.
Create Lead ListTool to create a new lead list.
Create WebhookTool to create a new webhook endpoint.
Delete API KeyTool to delete an API key.
Delete CampaignTool to delete a campaign.
Delete LeadTool to delete a lead by its ID.
Delete Lead ListTool to delete a lead list by ID.
Delete WebhookTool to delete a webhook.
Disable Account WarmupTool to disable the warm-up process for email accounts.
Enable Account WarmupTool to enable the warm-up process for email accounts.
Get CampaignTool to retrieve campaign details.
Get Campaign AnalyticsTool to retrieve analytics for campaigns.
Get Daily Campaign AnalyticsTool to retrieve daily analytics for a campaign.
Get Email Service Provider OptionsTool to retrieve email service provider options for inbox placement tests.
Get Inbox Placement TestTool to retrieve inbox placement test results.
Get LeadTool to retrieve details of a specific lead by its ID.
Get Lead ListTool to retrieve details of a specific lead list by its ID.
Get Lead List Verification StatsTool to retrieve verification statistics for a lead list.
Get WebhookTool to retrieve details of a specific webhook subscription.
Get Webhook EventTool to retrieve details of a specific webhook event.
List Email AccountsTool to list all email accounts for the authenticated user.
List API KeysTool to list all API keys.
List CampaignsTool to list all campaigns.
List Custom TagsTool to list custom tags.
List DFY Email Account OrdersTool to list DFY email account orders.
List EmailsTool to list emails.
List Inbox Placement Blacklist & SpamAssassin ReportsTool to list inbox placement blacklist & SpamAssassin reports.
List Inbox Placement TestsTool to list inbox placement tests.
List Lead ListsTool to list all lead lists.
List LeadsTool to list leads.
List Email ThreadsTool to list email threads.
List Webhook EventsTool to list webhook events.
List WebhooksTool to list configured webhooks.
Mark Thread As ReadTool to mark all emails in a specific thread as read.
Merge LeadsTool to merge multiple leads into a single lead.
Search Campaigns by Lead EmailTool to search campaigns by a lead's email address.
Update CampaignTool to update details of a campaign.
Update LeadTool to update a lead's details.
Update Lead Interest StatusTool to update a lead's interest status.
Update Lead ListTool to update details of a specific lead list by its ID.
Verify EmailTool to initiate email verification.

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

What is Tool Router?

Composio's Tool Router 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 Tool Router

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Tool Router works

The Tool Router 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

Prerequisites

Before starting, make sure you have:
  • Node.js 18 or higher
  • A Composio account with an active API key
  • An OpenAI API key
  • Basic familiarity with TypeScript

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key.
  • You need credits or a connected billing setup to use the models.
  • Store the key somewhere safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Go to Settings and copy your API key.
  • This key lets your Mastra agent talk to Composio and reach Instantly through MCP.

Install dependencies

bash
npm install @composio/core @mastra/core @mastra/mcp @ai-sdk/openai dotenv

Install the required packages.

What's happening:

  • @composio/core is the Composio SDK for creating MCP sessions
  • @mastra/core provides the Agent class
  • @mastra/mcp is Mastra's MCP client
  • @ai-sdk/openai is the model wrapper for OpenAI
  • dotenv loads environment variables from .env

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_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
  • COMPOSIO_USER_ID tells Composio which user this session belongs to
  • OPENAI_API_KEY lets the Mastra agent call OpenAI models

Import libraries and validate environment

typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
import { MCPClient } from "@mastra/mcp";
import { Composio } from "@composio/core";
import * as readline from "readline";

import type { AiMessageType } from "@mastra/core/agent";

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

if (!openaiAPIKey) 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 as string,
});
What's happening:
  • dotenv/config auto loads your .env so process.env.* is available
  • openai gives you a Mastra compatible model wrapper
  • Agent is the Mastra agent that will call tools and produce answers
  • MCPClient connects Mastra to your Composio MCP server
  • Composio is used to create a Tool Router session

Create a Tool Router session for Instantly

typescript
async function main() {
  const session = await composio.create(
    composioUserID as string,
    {
      toolkits: ["instantly"],
    },
  );

  const composioMCPUrl = session.mcp.url;
  console.log("Instantly MCP URL:", composioMCPUrl);
What's happening:
  • create spins up a short-lived MCP HTTP endpoint for this user
  • The toolkits array contains "instantly" for Instantly access
  • session.mcp.url is the MCP URL that Mastra's MCPClient will connect to

Configure Mastra MCP client and fetch tools

typescript
const mcpClient = new MCPClient({
    id: composioUserID as string,
    servers: {
      nasdaq: {
        url: new URL(composioMCPUrl),
        requestInit: {
          headers: session.mcp.headers,
        },
      },
    },
    timeout: 30_000,
  });

console.log("Fetching MCP tools from Composio...");
const composioTools = await mcpClient.getTools();
console.log("Number of tools:", Object.keys(composioTools).length);
What's happening:
  • MCPClient takes an id for this client and a list of MCP servers
  • The headers property includes the x-api-key for authentication
  • getTools fetches the tool definitions exposed by the Instantly toolkit

Create the Mastra agent

typescript
const agent = new Agent({
    name: "instantly-mastra-agent",
    instructions: "You are an AI agent with Instantly tools via Composio.",
    model: "openai/gpt-5",
  });
What's happening:
  • Agent is the core Mastra agent
  • name is just an identifier for logging and debugging
  • instructions guide the agent to use tools instead of only answering in natural language
  • model uses openai("gpt-5") to configure the underlying LLM

Set up interactive chat interface

typescript
let messages: AiMessageType[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end.\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({
    id: crypto.randomUUID(),
    role: "user",
    content: trimmedInput,
  });

  console.log("\nAgent is thinking...\n");

  try {
    const response = await agent.generate(messages, {
      toolsets: {
        instantly: composioTools,
      },
      maxSteps: 8,
    });

    const { text } = response;

    if (text && text.trim().length > 0) {
      console.log(`Agent: ${text}\n`);
        messages.push({
          id: crypto.randomUUID(),
          role: "assistant",
          content: text,
        });
      }
    } catch (error) {
      console.error("\nError:", error);
    }

    rl.prompt();
  });

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

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});
What's happening:
  • messages keeps the full conversation history in Mastra's expected format
  • agent.generate runs the agent with conversation history and Instantly toolsets
  • maxSteps limits how many tool calls the agent can take in a single run
  • onStepFinish is a hook that prints intermediate steps for debugging

Complete Code

Here's the complete code to get you started with Instantly and Mastra AI:

typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
import { MCPClient } from "@mastra/mcp";
import { Composio } from "@composio/core";
import * as readline from "readline";

import type { AiMessageType } from "@mastra/core/agent";

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

if (!openaiAPIKey) 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 as string });

async function main() {
  const session = await composio.create(composioUserID as string, {
    toolkits: ["instantly"],
  });

  const composioMCPUrl = session.mcp.url;

  const mcpClient = new MCPClient({
    id: composioUserID as string,
    servers: {
      instantly: {
        url: new URL(composioMCPUrl),
        requestInit: {
          headers: session.mcp.headers,
        },
      },
    },
    timeout: 30_000,
  });

  const composioTools = await mcpClient.getTools();

  const agent = new Agent({
    name: "instantly-mastra-agent",
    instructions: "You are an AI agent with Instantly tools via Composio.",
    model: "openai/gpt-5",
  });

  let messages: AiMessageType[] = [];

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

  rl.prompt();

  rl.on("line", async (input: string) => {
    const trimmed = input.trim();
    if (["exit", "quit"].includes(trimmed.toLowerCase())) {
      rl.close();
      return;
    }

    messages.push({ id: crypto.randomUUID(), role: "user", content: trimmed });

    const { text } = await agent.generate(messages, {
      toolsets: { instantly: composioTools },
      maxSteps: 8,
    });

    if (text) {
      console.log(`Agent: ${text}\n`);
      messages.push({ id: crypto.randomUUID(), role: "assistant", content: text });
    }

    rl.prompt();
  });

  rl.on("close", async () => {
    await mcpClient.disconnect();
    process.exit(0);
  });
}

main();

Conclusion

You've built a Mastra AI agent that can interact with Instantly through Composio's Tool Router. You can extend this further by:
  • Adding other toolkits like Gmail, Slack, or GitHub
  • Building a web-based chat interface around this agent
  • Using multiple MCP endpoints to enable cross-app workflows

How to build Instantly MCP Agent with another framework

OpenAI Agents SDK

OpenAI Agents SDK

Use Instantly MCP with OpenAI Agents SDK

Claude Agent SDK

Claude Agent SDK

Use Instantly MCP with Claude Agent SDK

Google ADK

Google ADK

Use Instantly MCP with Google ADK

LangChain

LangChain

Use Instantly MCP with LangChain

Vercel AI SDK

Vercel AI SDK

Use Instantly MCP with Vercel AI SDK

LlamaIndex

LlamaIndex

Use Instantly MCP with LlamaIndex

CrewAI

CrewAI

Use Instantly MCP with CrewAI

FAQ

What are the differences in Tool Router MCP and Instantly MCP?

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

Can I use Tool Router MCP with Mastra AI?

Yes, you can. Mastra AI 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 Instantly tools.

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

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

Used by agents from

Context
ASU
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
ASU
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
ASU
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

Never worry about agent reliability

We handle tool reliability, observability, and security so you never have to second-guess an agent action.

Book a call↗Get started for free