How to integrate Constant Contact MCP with Vercel AI SDK v6

This guide walks you through connecting Constant Contact to Vercel AI SDK v6 using the Composio tool router. By the end, you'll have a working Constant Contact agent that can create newsletter draft for new subscribers, list contacts added this week, segment inactive constant contact subscribers through natural language commands. This guide will help you understand how to give your Vercel AI SDK agent real control over a Constant Contact account through Composio's Constant Contact MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Constant Contact logoConstant Contact
Oauth2

Constant Contact is an email marketing and automation platform for small businesses. It helps teams build campaigns, manage contacts, and grow customer relationships.

93 Tools

Introduction

This guide walks you through connecting Constant Contact to Vercel AI SDK v6 using the Composio tool router. By the end, you'll have a working Constant Contact agent that can create newsletter draft for new subscribers, list contacts added this week, segment inactive constant contact subscribers through natural language commands.

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

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

Also integrate Constant Contact with

TL;DR

Here's what you'll learn:
  • How to set up and configure a Vercel AI SDK agent with Constant Contact integration
  • Using Composio's Tool Router to dynamically load and access Constant Contact 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 Constant Contact MCP server, and what's possible with it?

The Constant Contact MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Constant Contact account. It provides structured and secure access so your agent can perform Constant Contact operations on your behalf.

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 you begin, make sure you have:
  • Node.js and npm installed
  • A Composio account with API key
  • An OpenAI API key
2

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.
3

Install required dependencies

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

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
4

Set up environment variables

bash
OPENAI_API_KEY=your_openai_api_key_here
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_user_id_here

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
5

Import required modules and validate environment

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,
});
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
6

Create Tool Router session and initialize MCP client

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

  const mcpUrl = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Constant Contact 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 Constant Contact-related tools through the MCP protocol
7

Connect to MCP server and retrieve tools

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();
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 Constant Contact tools that the agent can use
8

Initialize conversation and CLI interface

typescript
let messages: ModelMessage[] = [];

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

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

rl.prompt();
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
9

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

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);
});
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 Constant Contact 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

Complete Code

Here's the complete code to get you started with Constant Contact and Vercel AI SDK:

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: ["constant_contact"],
  });

  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 constant_contact, 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 Constant Contact 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.
TOOLS

Supported Tools

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

Add Account Email Address

Add a new email address to a Constant Contact account.

Add Contact Taggings

Add Tags to Contacts.

Add list memberships

Add Contacts to Lists creates an activity to add contacts to one or more contact lists.

Copy Event

POST (copy) an existing event in Constant Contact.

Count Contact Consents

GET contact consent counts for a Constant Contact account.

Create Contact

Create a new contact in Constant Contact.

Create contact from sign-up form

Create or Update a Contact via sign-up form.

Create Contact List

Create a new contact list in Constant Contact.

Create contact tag

POST (Create) a Tag.

Create Custom Field

Create a new custom field for contacts in Constant Contact.

Create Email Campaign

Create a new email campaign in Constant Contact.

Create Event

Create a new event with default settings in Constant Contact.

Create Resend to Non-openers

Create a resend to non-openers campaign activity for an email campaign.

Create Social Post

Create a new social media post campaign.

Delete contact

DELETE a specific contact from your Constant Contact account.

Delete Contact List

Permanently deletes a contact list from Constant Contact by its ID.

Create contact delete activity

Delete multiple contacts in bulk by submitting a contact_delete activity.

Delete contact tag

Delete a specific contact tag from your Constant Contact account.

Delete contact tags

Delete one or more tags from contacts in Constant Contact.

Delete custom field

DELETE a specific contact custom field from your Constant Contact account.

Delete custom fields

Delete one or more custom fields from a Constant Contact account.

Delete Email Campaign

DELETE an Email Campaign from your Constant Contact account.

Delete contact list activity

Delete one or more contact lists from your Constant Contact account by submitting a list delete activity.

Delete Segment

Permanently deletes a segment from Constant Contact by its ID.

Export Contacts

Create a bulk activity that exports contacts to a CSV file.

Get account physical address

GET the Physical Address for the Account.

Get account summary

GET a summary of account details for a Constant Contact account.

Get activity status

GET the status of a specific bulk activity.

Get contact

GET a contact by their unique ID.

Get contact activity summary report

GET contact tracking activity summary for a specific contact.

Get Contact List

GET details for a specific contact list by its ID.

Get Contact Open and Click Rates Report

GET average open and click rates for a contact.

Get Contacts Export File

Retrieve the exported contacts file from a completed export contacts activity.

Get Contact SMS Engagement History

GET SMS Engagement History for a Contact.

Get contact tag details

GET Tag Details - Retrieves detailed information about a specific contact tag.

Get custom field

GET a custom field by its unique ID.

Get email campaign details

GET details for a single email campaign using its campaign ID.

Get Email Campaign Activity

GET details for a specific email campaign activity by its ID.

Get email campaign activity preview

GET the HTML Preview of an Email Campaign Activity.

Get Email Campaign Activity Schedule

GET an email campaign activity schedule.

Get email campaign activity send history

GET the send history of an email campaign activity.

Get email campaign ID cross-references

GET a collection of V2 and V3 API Email Campaign ID cross-references.

Get Email Campaign Statistics Report

GET statistics for one or more email campaigns.

Get Event

GET details for a single event by its unique ID.

Get list ID cross-references

GET a collection of V2 and V3 API List IDs cross-references.

Get Partner Webhook Subscription

GET details for a specific Partner Webhook Topic Subscription by its ID.

Get resend to non-openers

GET Details for a Resend to Non-openers Campaign Activity.

Get Segment

GET details for a specific segment by its unique ID.

Import contacts from CSV file

Import contacts into Constant Contact from a CSV file.

Import contacts from JSON

Bulk import contacts into Constant Contact using JSON format.

List account email addresses

GET a Collection of Account Email Addresses.

List account user privileges

Get the user privileges associated with your access token.

List activity statuses

GET a collection of bulk activities.

List Contact Lists

GET all contact lists for the Constant Contact account.

List contacts

GET Contacts Collection to retrieve a list of contacts from Constant Contact.

List contact tags

GET Details for All Tags - Retrieves all contact tags for the account.

List contact custom fields

GET custom_fields Collection to retrieve all contact custom field definitions.

List Email Campaigns

GET a collection of email campaigns from Constant Contact.

List Email Campaign Summaries Report

GET an Email Campaigns Summary Report from Constant Contact.

List Email Did Not Opens Report

GET an Email Did Not Opens Report to retrieve a list of contacts who did not open a specific email campaign.

List email forwards report

GET an Email Forwards Report for a specific email campaign activity.

List email opt-outs report

GET an Email Opt-outs Report for a specific email campaign activity.

List Email Unique Opens Report

GET an email unique opens report for a campaign activity.

List Events

GET a collection of events from Constant Contact.

List event track registrations

GET registrations for an event track to retrieve a list of registrations.

List Landing Page Contact Opens Report

GET a Contacts Opens Landing Page Report.

List Landing Page Unique Contact Adds Report

GET a Unique Contacts Adds Landing Page Report for a specific landing page campaign activity.

List Landing Page Unique Contact Clicks Report

GET unique contact clicks data for a landing page campaign.

List Landing Page Unique Contact Opens Report

GET a Unique Contacts Opens Landing Page Report to retrieve a list of contacts who uniquely opened a specific landing page campaign.

List landing page unique contact updates report

GET a Unique Contacts Updates Landing Page Report for a specific landing page campaign activity.

List Segments

GET all segments for the Constant Contact account.

List SMS Campaign Summaries Report

GET an SMS Campaigns Summary Report.

List Social Connections

GET social network connections for a Constant Contact account.

List Social Hashtag Groups

GET hashtag groups - Retrieves a paginated list of social hashtag groups.

List Social Profiles

GET social media profiles from Constant Contact.

Remove Contact Tagging

Remove tagging from contacts in Constant Contact.

Remove Tags from Contacts

Remove tags from contacts in Constant Contact.

Remove contacts from lists

Create a Remove Contacts from Lists activity to remove contacts from one or more lists.

Rename Email Campaign

PATCH (Update) the name of an existing email campaign in Constant Contact.

Rename Segment

PATCH (rename) an existing segment in Constant Contact.

Resubscribe Contact

Resubscribe an unsubscribed contact to one or more contact lists.

Undo Event Ticket Check-In

Undo check-in for event tickets.

Update Account Details

PUT (update) Account Details for the authenticated user.

Update Account Physical Address

PUT (update) the Physical Address for an Account.

Update Contact

PUT (update) an existing contact in Constant Contact.

Update Contact List

PUT (update) an existing contact list in Constant Contact.

Update Contact Tag

PUT (Update) a Tag.

Update Custom Field

Update an existing contact custom field in Constant Contact.

Update Email Campaign Activity

PUT (Update) an Email Campaign Activity in Constant Contact.

Update Event

PATCH (update) an existing event in Constant Contact.

Update Event Track Registration Payment Status

Update the payment status for event track registrations in Constant Contact.

Update Event Track Registrations

PUT (update) registration status for event track registrations.

Update Segment

PUT (update) an existing segment in Constant Contact.

FAQ

Frequently asked questions

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

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 Constant Contact tools.

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

Start with Constant Contact.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Constant Contact tool your agent needs.Free to start.

Start building