How to integrate Sendfox MCP with OpenAI Agents SDK

This guide walks you through connecting Sendfox to the OpenAI Agents SDK using the Composio tool router. By the end, you'll have a working Sendfox agent that can list all active campaigns this week, unsubscribe a contact by email address, retrieve all contacts from your main list through natural language commands. This guide will help you understand how to give your OpenAI Agents SDK agent real control over a Sendfox account through Composio's Sendfox MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Sendfox logoSendfox
Api Key

Sendfox is an email marketing platform focused on simple, affordable campaign management for creators and small businesses. It lets you grow and engage your audience with automated newsletters and easy contact organization.

17 Tools

Introduction

This guide walks you through connecting Sendfox to the OpenAI Agents SDK using the Composio tool router. By the end, you'll have a working Sendfox agent that can list all active campaigns this week, unsubscribe a contact by email address, retrieve all contacts from your main list through natural language commands.

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

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

Also integrate Sendfox with

TL;DR

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

What is OpenAI Agents SDK?

The OpenAI Agents SDK is a lightweight framework for building AI agents that can use tools and maintain conversation state. It provides a simple interface for creating agents with hosted MCP tool support.

Key features include:

  • Hosted MCP Tools: Connect to external services through hosted MCP endpoints
  • SQLite Sessions: Persist conversation history across interactions
  • Simple API: Clean interface with Agent, Runner, and tool configuration
  • Streaming Support: Real-time response streaming for interactive applications

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

The Sendfox MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Sendfox account. It provides structured and secure access to your contact lists, campaigns, automations, and more, so your agent can fetch contacts, manage lists, retrieve campaign data, and automate subscriber actions on your behalf.

  • Contact management and lookup: Instantly retrieve contact details by email or ID, fetch all contacts, or discover specific fields to personalize your outreach.
  • List organization and updates: Ask your agent to fetch all your Sendfox lists, get details for a specific list, or remove contacts from lists as needed.
  • Campaign and automation insights: Effortlessly retrieve paginated lists of campaigns or automations, so you can stay on top of your email marketing performance.
  • Subscription and unsubscribe actions: Let your agent globally unsubscribe a contact or handle opt-outs automatically for better list hygiene.
  • Discover contact field metadata: Pull all available contact fields to help with dynamic contact creation or targeted updates.

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 OpenAI API Key
  • Primary know-how of OpenAI Agents SDK
  • A live Sendfox project
  • Some knowledge of Python or Typescript
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
3

Install dependencies

npm install @composio/openai-agents @openai/agents dotenv

Install the Composio SDK and the OpenAI Agents SDK.

4

Set up environment variables

bash
OPENAI_API_KEY=sk-...your-api-key
COMPOSIO_API_KEY=your-api-key
USER_ID=composio_user@gmail.com

Create a .env file and add your OpenAI and Composio API keys.

5

Import dependencies

import 'dotenv/config';
import { Composio } from '@composio/core';
import { OpenAIAgentsProvider } from '@composio/openai-agents';
import { Agent, hostedMcpTool, run, OpenAIConversationsSession } from '@openai/agents';
import * as readline from 'readline';
What's happening:
  • You're importing all necessary libraries.
  • The Composio and OpenAIAgentsProvider classes are imported to connect your OpenAI agent to Composio tools like Sendfox.
6

Set up the Composio instance

dotenv.config();

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.USER_ID;

if (!composioApiKey) {
  throw new Error('COMPOSIO_API_KEY is not set. Create a .env file with COMPOSIO_API_KEY=your_key');
}
if (!userId) {
  throw new Error('USER_ID is not set');
}

// Initialize Composio
const composio = new Composio({
  apiKey: composioApiKey,
  provider: new OpenAIAgentsProvider(),
});
What's happening:
  • dotenv.config() loads your .env file so COMPOSIO_API_KEY and USER_ID are available as environment variables.
  • Creating a Composio instance using the API Key and OpenAIAgentsProvider class.
7

Create a Tool Router session

// Create Tool Router session for Sendfox
const session = await composio.create(userId as string, {
  toolkits: ['sendfox'],
});
const mcpUrl = session.mcp.url;

What is happening:

  • You give the Tool Router the user id and the toolkits you want available. Here, it is only sendfox.
  • The router checks the user's Sendfox connection and prepares the MCP endpoint.
  • The returned session.mcp.url is the MCP URL that your agent will use to access Sendfox.
  • This approach keeps things lightweight and lets the agent request Sendfox tools only when needed during the conversation.
8

Configure the agent

// Configure agent with MCP tool
const agent = new Agent({
  name: 'Assistant',
  model: 'gpt-5',
  instructions:
    'You are a helpful assistant that can access Sendfox. Help users perform Sendfox operations through natural language.',
  tools: [
    hostedMcpTool({
      serverLabel: 'tool_router',
      serverUrl: mcpUrl,
      headers: { 'x-api-key': composioApiKey },
      requireApproval: 'never',
    }),
  ],
});
What's happening:
  • We're creating an Agent instance with a name, model (gpt-5), and clear instructions about its purpose.
  • The agent's instructions tell it that it can access Sendfox and help with queries, inserts, updates, authentication, and fetching database information.
  • The tools array includes a hostedMcpTool that connects to the MCP server URL we created earlier.
  • The headers object includes the Composio API key for secure authentication with the MCP server.
  • requireApproval: 'never' means the agent can execute Sendfox operations without asking for permission each time, making interactions smoother.
9

Start chat loop and handle conversation

// Keep conversation state across turns
const conversationSession = new OpenAIConversationsSession();

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

console.log('\nComposio Tool Router session created.');
console.log('\nChat started. Type your requests below.');
console.log("Commands: 'exit', 'quit', or 'q' to end\n");

try {
  const first = await run(agent, 'What can you help me with?', { session: conversationSession });
  console.log(`Assistant: ${first.finalOutput}\n`);
} catch (e) {
  console.error('Error:', e instanceof Error ? e.message : e, '\n');
}

rl.prompt();

rl.on('line', async (userInput) => {
  const text = userInput.trim();

  if (['exit', 'quit', 'q'].includes(text.toLowerCase())) {
    console.log('Goodbye!');
    rl.close();
    process.exit(0);
  }

  if (!text) {
    rl.prompt();
    return;
  }

  try {
    const result = await run(agent, text, { session: conversationSession });
    console.log(`\nAssistant: ${result.finalOutput}\n`);
  } catch (e) {
    console.error('Error:', e instanceof Error ? e.message : e, '\n');
  }

  rl.prompt();
});

rl.on('close', () => {
  console.log('\n👋 Session ended.');
  process.exit(0);
});
What's happening:
  • The program prints a session URL that you visit to authorize Sendfox.
  • After authorization, the chat begins.
  • Each message you type is processed by the agent using run().
  • The responses are printed to the console.
  • Typing exit, quit, or q cleanly ends the chat.

Complete Code

Here's the complete code to get you started with Sendfox and OpenAI Agents SDK:

import 'dotenv/config';
import { Composio } from '@composio/core';
import { OpenAIAgentsProvider } from '@composio/openai-agents';
import { Agent, hostedMcpTool, run, OpenAIConversationsSession } from '@openai/agents';
import * as readline from 'readline';

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.USER_ID;

if (!composioApiKey) {
  throw new Error('COMPOSIO_API_KEY is not set. Create a .env file with COMPOSIO_API_KEY=your_key');
}
if (!userId) {
  throw new Error('USER_ID is not set');
}

// Initialize Composio
const composio = new Composio({
  apiKey: composioApiKey,
  provider: new OpenAIAgentsProvider(),
});

async function main() {
  // Create Tool Router session
  const session = await composio.create(userId as string, {
    toolkits: ['sendfox'],
  });
  const mcpUrl = session.mcp.url;

  // Configure agent with MCP tool
  const agent = new Agent({
    name: 'Assistant',
    model: 'gpt-5',
    instructions:
      'You are a helpful assistant that can access Sendfox. Help users perform Sendfox operations through natural language.',
    tools: [
      hostedMcpTool({
        serverLabel: 'tool_router',
        serverUrl: mcpUrl,
        headers: { 'x-api-key': composioApiKey },
        requireApproval: 'never',
      }),
    ],
  });

  // Keep conversation state across turns
  const conversationSession = new OpenAIConversationsSession();

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

  console.log('\nComposio Tool Router session created.');
  console.log('\nChat started. Type your requests below.');
  console.log("Commands: 'exit', 'quit', or 'q' to end\n");

  try {
    const first = await run(agent, 'What can you help me with?', { session: conversationSession });
    console.log(`Assistant: ${first.finalOutput}\n`);
  } catch (e) {
    console.error('Error:', e instanceof Error ? e.message : e, '\n');
  }

  rl.prompt();

  rl.on('line', async (userInput) => {
    const text = userInput.trim();

    if (['exit', 'quit', 'q'].includes(text.toLowerCase())) {
      console.log('Goodbye!');
      rl.close();
      process.exit(0);
    }

    if (!text) {
      rl.prompt();
      return;
    }

    try {
      const result = await run(agent, text, { session: conversationSession });
      console.log(`\nAssistant: ${result.finalOutput}\n`);
    } catch (e) {
      console.error('Error:', e instanceof Error ? e.message : e, '\n');
    }

    rl.prompt();
  });

  rl.on('close', () => {
    console.log('\nSession ended.');
    process.exit(0);
  });
}

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

Conclusion

This was a starter code for integrating Sendfox MCP with OpenAI Agents SDK to build a functional AI agent that can interact with Sendfox.

Key features:

  • Hosted MCP tool integration through Composio's Tool Router
  • SQLite session persistence for conversation history
  • Simple async chat loop for interactive testing
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS

Supported Tools

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

Delete Contact from List

Tool to remove a contact from a specific list in SendFox.

Get Automations

Tool to retrieve a list of automations.

Get Campaign by ID

Retrieve details for a specific campaign by its ID from SendFox.

Get Campaigns

Retrieve a paginated list of email campaigns from SendFox.

Get Contact by ID

Retrieves a contact's details by their unique ID from SendFox.

Get Contact Fields

Retrieves all contact fields available in the SendFox account.

Get Contacts

Tool to retrieve a paginated list of contacts.

Get Contacts in List

Tool to retrieve contacts in a specific list.

Get Current User

Tool to retrieve information about the authenticated user from SendFox.

Get Forms

Tool to retrieve a paginated list of forms from SendFox.

Get List by ID

Retrieves details of a specific contact list by its ID from SendFox.

Get Lists

Retrieve all contact lists from your SendFox account with pagination support.

List Contact Fields

Tool to list all custom contact fields defined by the user.

List Unsubscribed Contacts

Tool to retrieve a paginated list of contacts who have unsubscribed.

Unsubscribe Contact

Unsubscribe a contact from all email communications in your SendFox account.

Create Contact

Create a new contact (subscriber) in your SendFox account.

Create List

Create a new contact list in your SendFox account.

FAQ

Frequently asked questions

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

Yes, you can. OpenAI Agents 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 Sendfox tools.

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

Start with Sendfox.It takes 30 seconds.

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

Start building