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How to integrate Sendfox MCP with Claude Agent SDK

Connect Claude Agent SDK to Sendfox MCP. List all active campaigns this week, unsubscribe a contact by email address, and more using natural language, with authentication handled for you.

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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 Claude Agent SDK using the Composio tool router. By the end, you'll have a working Sendfox agent that can create contacts and lists, unsubscribe contacts, review campaigns and automations, browse forms, and manage contact fields through natural language commands.

This guide will help you understand how to give your Claude Agent 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

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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 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 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 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 Claude/Anthropic API Key
  • Primary know-how of Claude Agents SDK
  • A Sendfox 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 Sendfox 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 Sendfox
  const session = await composio.create(USER_ID, {
    toolkits: ['sendfox'],
  });
  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 Sendfox
  • 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 Sendfox 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 Sendfox
  • 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 Sendfox 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: ['sendfox']
  });
  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 Sendfox 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 Sendfox 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 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

Retrieve automations from the SendFox account.

Get Campaign by ID

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

Get Campaigns

Retrieve a page of SendFox email campaigns, with subject and timestamps when provided.

Get Contact by ID

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

Get Contact Fields

Retrieve contact fields from SendFox.

Get Contacts

Tool to retrieve a paginated list of contacts.

Get Contacts in List

Retrieve a page of contacts belonging to a specific list, optionally filtering by search query.

Get Current User

Retrieve information about the authenticated SendFox user, including name and email.

Get Forms

Retrieve a page of SendFox forms, optionally searching by query.

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

Retrieve a page of the user's custom contact fields, including their IDs, labels, names, and types.

List Unsubscribed Contacts

Retrieve a paginated list of unsubscribed contacts, optionally filtered by search query.

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.

FRAMEWORKS

How to build Sendfox MCP Agent with another framework

Claude Code logo

Claude Code

Use Sendfox MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Sendfox MCP with Claude Cowork

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Sendfox MCP with OpenAI Agents SDK

Codex logo

Codex

Use Sendfox MCP with Codex

OpenClaw logo

OpenClaw

Use Sendfox MCP with OpenClaw

Hermes logo

Hermes

Use Sendfox MCP with Hermes

Atomic Agent logo

Atomic Agent

Use Sendfox MCP with Atomic Agent

Google ADK logo

Google ADK

Use Sendfox MCP with Google ADK

LangChain logo

LangChain

Use Sendfox MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Sendfox MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Sendfox MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Sendfox MCP with LlamaIndex

CrewAI logo

CrewAI

Use Sendfox MCP with CrewAI

Pydantic AI logo

Pydantic AI

Use Sendfox MCP with Pydantic AI

AutoGen logo

AutoGen

Use Sendfox MCP with AutoGen

FAQ

Frequently asked questions

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