How to integrate Cardly MCP with Claude Agent SDK

This guide walks you through connecting Cardly to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Cardly agent that can create a new contact list named 'vip clients', list all available artwork for our next campaign, generate a preview of a card using latest artwork through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a Cardly account through Composio's Cardly MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Api Key

Cardly is a platform for creating and sending personalized direct mail to customers. It helps businesses break through the digital clutter by getting real engagement via physical mailboxes.

29 Tools

Introduction

This guide walks you through connecting Cardly to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Cardly agent that can create a new contact list named 'vip clients', list all available artwork for our next campaign, generate a preview of a card using latest artwork through natural language commands.

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

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

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

The Cardly MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Cardly account. It provides structured and secure access to your Cardly workspace, so your agent can create contact lists, generate card previews, manage invitations, and access artwork or credit history for seamless customer engagement tasks.

  • Automated contact list creation and management: Easily instruct your agent to set up new contact lists or manage existing ones, streamlining outreach campaigns and personalized mailings.
  • Card preview generation and artwork browsing: Let your agent generate watermarked card previews and browse available artwork to help you select the right designs before sending mailers.
  • Real-time credit and gift history access: Ask your agent to fetch your credit or gift credit history so you always know your account status and can track usage or plan new campaigns.
  • Invitation and webhook management: Direct your agent to handle invitations—listing, deleting, or auditing user invites—or manage webhooks for seamless integration with other systems.
  • Font and design asset exploration: Have your agent list available fonts and artwork, making it easier to choose creative assets for your next customer engagement initiative.

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

Create Contact List

Tool to add a new contact list.

Create Invitation

Tool to send an invitation to use your organisation portal.

Create Webhook

Tool to create a new webhook subscription.

Delete Invitation

Tool to delete an invitation by unique ID, immediately invalidating it for acceptance.

Delete Invitation by Email

Deletes a pending invitation by email address, immediately invalidating it and preventing acceptance.

Delete User

Tool to delete a user by unique ID, immediately revoking their access to your organisation portal.

Delete User by Email

Deletes a user by email address, immediately revoking their access to your organisation portal.

Delete Webhook

Tool to delete a webhook.

Echo Request

Tool to echo all request parameters, body, and headers for debugging purposes.

Generate Preview

Tool to generate a low-quality, watermarked preview document for a card.

Get Artwork

Tool to retrieve information on a specific piece of artwork by its unique ID.

Get Webhook

Tool to get details on an existing webhook.

List Artwork

Tool to retrieve the currently available artwork for your organisation.

List Contact Lists

Tool to retrieve all active contact lists for your organization.

List Credit History

Retrieves the account's credit transaction history showing all credits and debits.

List Doodles

Retrieve your currently available doodles from Cardly.

List Fonts

List available fonts for handwriting and text personalization in Cardly cards.

List Gift Credit History

Lists gift credit history records for your organization with pagination and optional time-based filtering.

List Invitations

Tool to retrieve active invitations for your organisation with optional filters.

List Media

Tool to retrieve the currently available media sizes for product artwork.

List Orders

Retrieves a paginated list of orders placed by your organization.

List Templates

Tool to retrieve your currently available templates from Cardly.

List Users

Tool to retrieve all users associated with your account.

List Webhooks

Retrieves all webhooks configured for your organization, including their status, target URLs, subscribed events, and delivery statistics.

List Writing Styles

Tool to list available writing styles.

Retrieve Account Balance

Tool to retrieve the current account and gift credit balances for your organisation.

Retrieve Order

Retrieves detailed information about a specific order by its ID.

Retrieve User

Retrieves detailed information about a specific user account by ID.

Update Webhook

Tool to update a webhook’s settings, including target URL and events.

FAQ

Frequently asked questions

With a standalone Cardly MCP server, the agents and LLMs can only access a fixed set of Cardly tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Cardly 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 Cardly tools.

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

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