How to integrate Ynab MCP with Claude Agent SDK

This guide walks you through connecting Ynab to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Ynab agent that can show your spending by category this week, add a new expense to groceries, list upcoming scheduled transactions through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a Ynab account through Composio's Ynab MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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YNAB (You Need A Budget) is a personal finance and budgeting platform that helps users track spending, plan budgets, and reach savings goals. It's designed to give you more control over your money and reduce financial stress.

27 Tools

Introduction

This guide walks you through connecting Ynab to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Ynab agent that can show your spending by category this week, add a new expense to groceries, list upcoming scheduled transactions through natural language commands.

This guide will help you understand how to give your Claude Agent SDK agent real control over a Ynab account through Composio's Ynab 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 Ynab
  • Configure an AI agent that can use Ynab as a tool
  • Run a live chat session where you can ask the agent to perform Ynab 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 Ynab MCP server, and what's possible with it?

The Ynab MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Ynab account. It provides structured and secure access to your budgeting data, so your agent can perform actions like tracking expenses, creating and adjusting budgets, fetching transaction history, and analyzing spending patterns on your behalf.

  • Automated transaction tracking: Let your agent fetch, categorize, or summarize recent transactions to keep your spending up to date.
  • Budget creation and adjustment: Instruct your agent to set up new budgets, update existing categories, or reallocate funds between envelopes as your needs change.
  • Spending analysis and reporting: Have your agent analyze your expenses, highlight trends, or generate summaries to help you understand where your money goes.
  • Goal monitoring and progress updates: Ask your agent to track progress toward savings or debt payoff goals, and notify you of milestones or needed adjustments.
  • Account and balance synchronization: Enable your agent to pull up-to-date balances from multiple accounts, ensuring your budget always reflects the latest financial picture.

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

Create a new account in a budget

Tool to create a new account in a budget.

Create Scheduled Transaction

Creates a scheduled (recurring) transaction in a YNAB budget.

Delete Scheduled Transaction

Permanently deletes a scheduled transaction from a YNAB budget.

Get Account by ID

Tool to retrieve a single account resource.

Get Budget By ID

Retrieve a complete budget export by ID, including all accounts, categories, payees, and transactions.

Get Budget Month

Tool to retrieve a specific budget month.

Get Budget Settings

Tool to retrieve budget-level settings.

Get Category by ID

Retrieve a single YNAB budget category by its ID.

Get Month Category By ID

Tool to retrieve a single category for a specific budget month.

Get Payee by ID

Tool to retrieve a single payee by its ID.

Get Scheduled Transaction by ID

Tool to retrieve a single scheduled transaction.

Get Transaction by ID

Tool to retrieve a single transaction by its ID.

Get Authorized User

Tool to retrieve the authorized user's information.

List Accounts

Retrieves all accounts for a specified YNAB budget.

List Budgets

Retrieves all budgets accessible to the authenticated YNAB user.

List Categories

Tool to list all category groups and their categories for a budget.

List Budget Months

Tool to list months for a budget with summary information.

List Payee Locations

Retrieves all GPS locations associated with payees in a budget.

List Payee Locations by Payee

Retrieves all GPS locations associated with a specific payee in a budget.

List payees in a budget

Tool to list payees in a budget.

List Scheduled Transactions

List all scheduled (recurring) transactions for a YNAB budget.

List Transactions

Tool to list transactions in a budget.

List Transactions by Account

Tool to list transactions for a specific account.

List Transactions by Category

Tool to list transactions for a specific category (excludes pending).

List Transactions by Payee

Tool to list transactions for a specific payee in a budget.

Update Payee

Tool to update a payee.

Update Scheduled Transaction

Update an existing scheduled transaction in YNAB.

FAQ

Frequently asked questions

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

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

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