How to integrate Square MCP with Claude Agent SDK

This guide walks you through connecting Square to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Square agent that can create and send an invoice to a customer, list all recent payments from last week, update item prices in your product catalog through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a Square account through Composio's Square MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Introduction

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

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

Also integrate Square with

OpenAI Agents SDK Claude Code Claude Cowork Codex OpenClaw Hermes CLI Google ADK LangChain Vercel AI SDK Mastra AI LlamaIndex CrewAI

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

The Square MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Square account. It provides structured and secure access to your Square business tools, so your agent can perform actions like processing payments, managing invoices, tracking orders, handling customers, and managing inventory on your behalf.

Seamless payment processing: Let your agent accept card payments, issue refunds, and manage transactions across your business locations.
Automated invoice creation and management: Ask your agent to generate, send, and monitor invoices for your customers, streamlining your billing process.
Order and fulfillment tracking: Enable your agent to view, update, and manage orders, helping you keep tabs on fulfillment and delivery status with ease.
Customer profile management: Have your agent create, update, or search customer profiles, making it easier to personalize service and maintain up-to-date records.
Inventory and item catalog control: Allow your agent to track stock levels, update item details, and organize your catalog for smooth retail operations.

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:

Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS

Prerequisites

Before starting, make sure you have:

Composio API Key and Claude/Anthropic API Key
Primary know-how of Claude Agents SDK
A Square account
Some knowledge of Python

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.

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

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

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 Square functionality

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 Square
  const session = await composio.create(USER_ID, {
    toolkits: ['square'],
  });
  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 Square
The returned url is the MCP server URL that your agent will use

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 Square 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 Square
maxTurns: 10 limits the conversation length to prevent excessive API usage

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'

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 Square 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: ['square']
  });
  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 Square 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 Square 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 Square action and event your agent gets out of the box.

Accept Dispute

Accept a dispute and acknowledge liability, returning funds to the cardholder.

Add Group to Customer

Tool to add a customer to a customer group.

Calculate Order

Tool to preview order pricing without creating an order.

Cancel Invoice

Cancels a Square invoice, preventing further payments from being collected.

Cancel Payment

Cancels (voids) a payment that is in APPROVED status.

Create Bulk Customers

Tool to create multiple customer profiles in a single request.

Create Card

Tool to create a card on file.

Create Customer

Tool to create a new customer profile in Square.

Create Customer Custom Attribute Definition

Tool to create a customer-related custom attribute definition.

Create Customer Group

Tool to create a new customer group for a business.

Create Dispute Evidence File

Tool to upload a file as dispute evidence.

Create Dispute Evidence Text

Upload text evidence for a dispute challenge.

Create Invoice Attachment

Upload and attach a file to a Square invoice.

Create Location

Tool to create a new business location in a Square account.

Create Location Custom Attribute Definition

Tool to create a location-related custom attribute definition.

Delete Customer

Tool to delete a Square customer profile.

Delete Customer Custom Attribute

Tool to delete a custom attribute from a customer profile.

Delete Customer Custom Attribute Definition

Tool to delete a customer-related custom attribute definition.

Delete Customer Group

Tool to delete a customer group by its ID.

Bulk Delete Customers

Tool to bulk delete customer profiles from Square.

Delete Dispute Evidence

Removes a specific piece of evidence from a dispute.

Delete Invoice

Tool to delete a Square invoice (only DRAFT invoices can be deleted).

Delete Invoice Attachment

Tool to delete an attachment from a Square invoice.

Delete Location Custom Attribute

Tool to delete a custom attribute from a location.

Delete Location Custom Attribute Definition

Tool to delete a location-related custom attribute definition.

Delete Locations Custom Attributes (Batch)

Tool to delete custom attributes from multiple locations in a single batch request.

Delete Merchant Custom Attribute

Tool to delete a custom attribute from a merchant profile.

Delete Merchant Custom Attribute Definition

Tool to delete a merchant-related custom attribute definition.

Delete Merchants Custom Attributes (Batch)

Tool to delete custom attributes from multiple merchants in a single batch request.

Delete Webhook Subscription

Permanently deletes a webhook subscription by its ID.

Get Business Booking Profile

Tool to retrieve the business booking profile for a Square merchant via GraphQL.

Get Current Merchant

Tool to retrieve merchant information associated with the access token using Square's GraphQL API.

Get Customer Custom Attribute

Retrieves a custom attribute from a customer profile in Square.

Get Customer Custom Attribute Definition

Tool to retrieve a customer-related custom attribute definition from Square.

Get Customers via GraphQL

Tool to retrieve customer profiles from Square Customer Directory using GraphQL API.

Get Dispute Evidence

Retrieves detailed information about a specific piece of evidence that was uploaded for a dispute.

Get Invoice

Retrieves detailed information about a specific Square invoice by its ID.

Get Merchant

Tool to retrieve detailed information about a specific Square merchant by ID.

Get Online Checkout Location Settings

Tool to retrieve location-level settings for Square online checkout.

List Channels

Tool to list requested channels from Square.

List Customer Custom Attribute Definitions

Tool to list customer-related custom attribute definitions from Square.

List Customer Custom Attribute Definitions (GraphQL)

Tool to retrieve customer custom attribute definitions via Square's GraphQL API.

List Customer Custom Attributes

Tool to list custom attributes for a customer profile.

List Customer Groups

Tool to retrieve the list of customer groups of a business.

List Customers

Tool to retrieve customer profiles associated with a Square account.

List Customer Segments

Tool to retrieve the list of customer segments of a business.

List Dispute Evidence

Tool to list evidence items associated with a given dispute.

List Invoices

Tool to list invoices for a Square location.

List Location Custom Attribute Definitions

Tool to list location-related custom attribute definitions from Square.

List Locations

Tool to retrieve all business locations from a Square account.

List Locations Custom Attributes

Tool to list custom attributes for a specific location in Square.

List Merchant Custom Attribute Definitions

Tool to list merchant-related custom attribute definitions from Square.

List Merchants

Tool to retrieve merchant account information associated with the access token.

List Merchants Custom Attributes

Tool to list custom attributes for a specific merchant in Square.

List Payments

Tool to list payments by location and time range to enable reconciliation and net sales reporting from Square POS.

List Webhook Event Types

Tool to list available webhook event types.

List Webhook Subscriptions

List all webhook subscriptions owned by your application.

Remove Group From Customer

Removes a customer from a customer group.

Retrieve Bulk Customers

Tool to retrieve multiple customer profiles in a single request.

Retrieve Channel

Retrieve a Square channel by its ID.

Bulk Retrieve Channels

Tool to bulk retrieve multiple Square channels by their IDs in a single request.

Retrieve Customer

Tool to retrieve detailed information about a specific Square customer by ID.

Retrieve Customer Group

Tool to retrieve a specific Square customer group by ID.

Retrieve Customer Segment

Tool to retrieve a specific customer segment by its ID.

Retrieve Dispute

Tool to retrieve a Square dispute by ID.

Retrieve Location

Tool to retrieve detailed information about a specific Square location by ID.

Retrieve Location Custom Attribute

Retrieves a custom attribute associated with a location in Square.

Retrieve Location Custom Attribute Definition

Tool to retrieve a location-related custom attribute definition.

Retrieve Merchant Custom Attribute

Retrieves a custom attribute associated with a merchant in Square.

Retrieve Merchant Custom Attribute Definition

Tool to retrieve a merchant-related custom attribute definition from Square.

Retrieve Merchants

Tool to retrieve merchant information including status, main location details, and capabilities using Square's GraphQL API.

Retrieve Order

Retrieves detailed information about a specific Square order by its ID.

Retrieve Payment Link

Retrieves a Square-hosted payment link by ID.

Retrieve Token Status

Tool to retrieve information about an OAuth access token or personal access token.

Retrieve Webhook Subscription

Retrieve a Square webhook subscription by its ID.

Search Customers

Tool to search customer profiles in Square Customer Directory.

Search Orders

Tool to search orders across one or more Square locations with filters.

Submit Dispute Evidence

Submits evidence for a dispute to the cardholder's bank.

Test Webhook Subscription

Tests a webhook subscription by sending a test event to the configured notification URL.

Update Customer

Tool to update an existing Square customer profile.

Update Customer Custom Attribute Definition

Tool to update a customer-related custom attribute definition in Square.

Update Customer Group

Tool to update a customer group's information by its ID.

Bulk Update Customers

Tool to update multiple customer profiles in a single batch operation.

Update Location

Tool to update an existing business location in a Square account.

Update Location Custom Attribute Definition

Tool to update a location-related custom attribute definition in Square.

Update Merchant Custom Attribute Definition

Tool to update a merchant-related custom attribute definition in Square.

Update Online Checkout Location Settings

Tool to update location-level settings for Square online checkout.

Update Order

Updates an existing Square order by adding, modifying, or removing fields.

Update Webhook Subscription

Tool to update a Square webhook subscription.

Update Webhook Subscription Signature Key

Tool to rotate the signature key for a webhook subscription.

Upsert Customer Custom Attribute

Tool to create or update a custom attribute for a customer profile.

Batch Upsert Customer Custom Attributes

Tool to create or update custom attributes for multiple customers in a single batch request.

Upsert Location Custom Attribute

Tool to create or update a custom attribute for a location.

Batch Upsert Locations Custom Attributes

Tool to create or update custom attributes for multiple locations in a single batch request.

Upsert Merchant Custom Attribute

Tool to create or update a custom attribute for a merchant profile.

Batch Upsert Merchants Custom Attributes

Tool to create or update custom attributes for multiple merchants in a single batch request.

FRAMEWORKS

How to build Square MCP Agent with another framework

OpenAI Agents SDK

Use Square MCP with OpenAI Agents SDK

Claude Code

Use Square MCP with Claude Code

Claude Cowork

Use Square MCP with Claude Cowork

Codex

Use Square MCP with Codex

OpenClaw

Use Square MCP with OpenClaw

Hermes

Use Square MCP with Hermes

CLI

Use Square MCP with CLI

Google ADK

Use Square MCP with Google ADK

LangChain

Use Square MCP with LangChain

Vercel AI SDK

Use Square MCP with Vercel AI SDK

Mastra AI

Use Square MCP with Mastra AI

LlamaIndex

Use Square MCP with LlamaIndex

CrewAI

Use Square MCP with CrewAI

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Addresszen

Api Key

Addresszen is a real-time address autocomplete and verification service. It helps capture accurate, deliverable addresses with instant suggestions and validation.

Asin data api

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Asin data api gives you detailed, real-time product data from Amazon, including price, rank, and reviews. Perfect for e-commerce pros and data-driven marketers who need instant marketplace insights.

Baselinker

Api Key

BaseLinker is an all-in-one e-commerce management platform connecting stores, marketplaces, carriers, and more. It streamlines order processing, inventory control, and automates your sales operations.

Bestbuy

Api Key

Best Buy is a leading retailer offering APIs for product, store, and recommendation data. Instantly access up-to-date retail insights for smarter shopping and decision-making.

FAQ

Frequently asked questions

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

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

Start with Square.It takes 30 seconds.

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

Start building

Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREE BOOK A DEMO

Karan skipped his own birthday party to fix our critical issue. It was 10pm and he diverted his Waymo to help us instead. This really sets the bar — it shows the commitment you need when users rely on your software.

Harsha Gaddipati

Co-founder, Slashy

A lot of students tell us that the moment their connected tools start talking to each other inside Opennote feels almost magical. The agent just knows them, and it's immensely helped keep new users on the platform.

Abhi Arya

Co-founder, Opennote

We chose Composio over Pipedream because it delivered depth where it mattered — niche tools and tricky edge cases other platforms simply ignored. That gave us confidence to scale without compromising.

Nirman Dave

CEO, Zams

As a solo builder, shipping fast is life or death. The only way I can outcompete incumbents is by outmanoeuvring them. Getting bogged down managing agent auth would have been a death sentence.

Ryan Yu

Founder, Extra Thursday

Before Composio, adding tool integrations was slow and resource-intensive. Each one could take weeks of engineering time, and maintaining them meant constantly keeping up with API changes.

Tomisin Jenrola

Founder & CEO, SwarmZero

With hands-on help from their founder, we integrated Gmail and Google Drive in just 30 minutes. This level of personal support and commitment is exactly what startups should strive for.

Jerome Leclanche

Co-Founder, Ingram Technologies

How to integrate Square MCP with Claude Agent SDK

Connect Square without auth hassles

Introduction

Also integrate Square with

TL;DR

What is Claude Agent SDK?

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

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

How the Composio SDK works

Step-by-step Guide

Prerequisites

Getting API Keys for Claude/Anthropic and Composio

Install dependencies

Set up environment variables

Import dependencies

Create a Composio instance and Tool Router session

Configure Claude Agent with MCP

Create client and start chat loop

Run the application

Complete Code

Conclusion

Supported Tools

How to build Square MCP Agent with another framework

OpenAI Agents SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

LangChain

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Explore Other Toolkits

Addresszen

Asin data api

Baselinker

Bestbuy

Frequently asked questions

What are the differences in Tool Router MCP and Square MCP?+

Can I use Tool Router MCP with Claude Agent SDK?+

Can I manage the permissions and scopes for Square while using Tool Router?+

How safe is my data with Composio Tool Router?+

Start with Square.It takes 30 seconds.

Teams ship real agents on Composio