How to integrate ApexVerify MCP with Claude Agent SDK

This guide walks you through connecting ApexVerify to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working ApexVerify agent that can validate new signup emails before import, normalize phone numbers for crm records, check batch contacts for invalid data through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a ApexVerify account through Composio's ApexVerify MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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ApexVerify is a contact-data validation service for emails and phone numbers. Use it to normalize, verify, and clean leads before they enter your systems.

10 Tools

Introduction

This guide walks you through connecting ApexVerify to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working ApexVerify agent that can validate new signup emails before import, normalize phone numbers for crm records, check batch contacts for invalid data through natural language commands.

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

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

Also integrate ApexVerify 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 ApexVerify
  • Configure an AI agent that can use ApexVerify as a tool
  • Run a live chat session where you can ask the agent to perform ApexVerify 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 ApexVerify MCP server, and what's possible with it?

The ApexVerify MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your ApexVerify account. It provides structured and secure access to contact verification and normalization, so your agent can verify individual contacts, process batches, export results, monitor credits, and manage verification jobs on your behalf.

  • Real-time contact verification: Have your agent verify a single email address or phone number and report whether the contact information is valid.
  • Batch verification management: Let the agent upload contact files, prepare them through parsing and deduplication, estimate verification costs, and launch paid verification.
  • Contact data normalization: Direct your agent to clean and normalize email addresses or phone numbers from line-delimited text files without using verification credits.
  • Batch tracking and exports: Instruct your agent to list batches, review their status and final statistics, and export completed results as structured JSON or an XLSX workbook.
  • Credit and batch cleanup: Have your agent check available email and phone verification credits or permanently delete batches you no longer need.

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 ApexVerify 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 ApexVerify 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 ApexVerify
  const session = await composio.create(USER_ID, {
    toolkits: ['apexverify'],
  });
  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 ApexVerify
  • 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 ApexVerify 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 ApexVerify
  • 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 ApexVerify 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: ['apexverify']
  });
  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 ApexVerify 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 ApexVerify 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 ApexVerify action and event your agent gets out of the box.

Delete Batch

Permanently delete one ApexVerify batch by its exact UUID.

Export Batch Results

Export a completed batch as structured JSON for analysis or as a downloadable XLSX workbook.

Get Account Credits

Return the connected ApexVerify account's available email and phone verification credit balances.

Get Batch Details

Get an ApexVerify batch's status, metadata, parsed-content counts, estimated verification cost, parameters, and final statistics.

Launch Batch Verification

Launch paid verification for a prepared batch.

List Batches

List verification batches, optionally restricted by creation time, one offset-controlled page at a time.

Normalize Data File

Normalize email addresses or phone numbers from a line-delimited TXT file without performing verification or consuming verification credits.

Prepare Batch

Start or repeat asynchronous parsing, deduplication, format cleanup, and verification-cost calculation for an uploaded batch.

Upload Verification Batch

Create an ApexVerify verification batch from a line-delimited TXT file.

Verify Email or Phone

Verify one email address or phone number in real time.

FRAMEWORKS

How to build ApexVerify MCP Agent with another framework

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OpenAI Agents SDK

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Claude Code logo

Claude Code

Use ApexVerify MCP with Claude Code

Claude Cowork logo

Claude Cowork

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Codex logo

Codex

Use ApexVerify MCP with Codex

OpenClaw logo

OpenClaw

Use ApexVerify MCP with OpenClaw

Hermes logo

Hermes

Use ApexVerify MCP with Hermes

CLI logo

CLI

Use ApexVerify MCP with CLI

Google ADK logo

Google ADK

Use ApexVerify MCP with Google ADK

LangChain logo

LangChain

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Vercel AI SDK logo

Vercel AI SDK

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Mastra AI logo

Mastra AI

Use ApexVerify MCP with Mastra AI

LlamaIndex logo

LlamaIndex

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CrewAI logo

CrewAI

Use ApexVerify MCP with CrewAI

FAQ

Frequently asked questions

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

Yes, you can. Claude Agent 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 ApexVerify tools.

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

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