How to integrate Ynab MCP with LangChain

This guide walks you through connecting Ynab to LangChain 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 LangChain 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 LangChain 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 LangChain 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.

Also integrate Ynab with

OpenAI Agents SDKClaude Agent SDKClaude CodeClaude CoworkCodexOpenClawHermesCLIGoogle ADKVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Connect your Ynab project to Composio
  • Create a Tool Router MCP session for Ynab
  • Initialize an MCP client and retrieve Ynab tools
  • Build a LangChain agent that can interact with Ynab
  • Set up an interactive chat interface for testing

What is LangChain?

LangChain is a framework for developing applications powered by language models. It provides tools and abstractions for building agents that can reason, use tools, and maintain conversation context.

Key features include:

  • Agent Framework: Build agents that can use tools and make decisions
  • MCP Integration: Connect to external services through Model Context Protocol adapters
  • Memory Management: Maintain conversation history across interactions
  • Multi-Provider Support: Works with OpenAI, Anthropic, and other LLM providers

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 step10 STEPS
1

Prerequisites

Before starting this tutorial, make sure you have:
  • Python 3.10 or higher installed on your system
  • A Composio account with an API key
  • An OpenAI API key
  • Basic familiarity with Python and async programming
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • 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 @composio/langchain @langchain/core @langchain/openai @langchain/mcp-adapters dotenv

Install the required packages for LangChain with MCP support.

What's happening:

  • @composio/langchain provides Composio integration for LangChain
  • @langchain/mcp-adapters enables MCP client connections
  • @langchain/core is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_composio_user_id_here
OPENAI_API_KEY=your_openai_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates your requests to Composio's API
  • COMPOSIO_USER_ID identifies the user for session management
  • OPENAI_API_KEY enables access to OpenAI's language models
5

Import dependencies

import { Composio } from '@composio/core';
import { LangchainProvider } from '@composio/langchain';
import { MultiServerMCPClient } from "@langchain/mcp-adapters";
import { createAgent } from "langchain";
import * as readline from 'readline';
import 'dotenv/config';

dotenv.config();
What's happening:
  • We're importing LangChain's MCP adapter and Composio SDK
  • The dotenv/config import loads environment variables from your .env file
  • This setup prepares the foundation for connecting LangChain with Ynab functionality through MCP
6

Initialize Composio client

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.COMPOSIO_USER_ID;

if (!composioApiKey) throw new Error('COMPOSIO_API_KEY is not set');
if (!userId) throw new Error('COMPOSIO_USER_ID is not set');

async function main() {
    const composio = new Composio({
        apiKey: composioApiKey as string,
        provider: new LangchainProvider()
    });
What's happening:
  • We're loading the COMPOSIO_API_KEY from environment variables and validating it exists
  • Creating a Composio instance that will manage our connection to Ynab tools
  • Validating that COMPOSIO_USER_ID is also set before proceeding
7

Create a Tool Router session

const session = await composio.create(
    userId as string,
    {
        toolkits: ['ynab']
    }
);

const url = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Ynab tools
  • The create method takes the user ID and specifies which toolkits should be available
  • The returned session.mcp.url is the MCP server URL that your agent will use
  • This approach allows the agent to dynamically load and use Ynab tools as needed
8

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "ynab-agent": {
        transport: "http",
        url: url,
        headers: {
            "x-api-key": process.env.COMPOSIO_API_KEY
        }
    }
});

const tools = await client.getTools();

const agent = createAgent({ model: "gpt-5", tools });
What's happening:
  • We're creating a MultiServerMCPClient that connects to our Ynab MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • getTools() retrieves all available Ynab tools that the agent can use
  • We're creating a LangChain agent using the GPT-5 model
9

Set up interactive chat interface

let conversationHistory: any[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log("Ask any Ynab related question or task to the agent.\n");

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
});

rl.prompt();

rl.on('line', async (userInput: string) => {
    const trimmedInput = userInput.trim();

    if (['exit', 'quit', 'bye'].includes(trimmedInput.toLowerCase())) {
        console.log("\nGoodbye!");
        rl.close();
        process.exit(0);
    }

    if (!trimmedInput) {
        rl.prompt();
        return;
    }

    conversationHistory.push({ role: "user", content: trimmedInput });
    console.log("\nAgent is thinking...\n");

    const response = await agent.invoke({ messages: conversationHistory });
    conversationHistory = response.messages;

    const finalResponse = response.messages[response.messages.length - 1]?.content;
    console.log(`Agent: ${finalResponse}\n`);
        
        rl.prompt();
    });

    rl.on('close', () => {
        console.log('\n👋 Session ended.');
        process.exit(0);
    });
What's happening:
  • We initialize an empty conversationHistory list to maintain context across interactions
  • A readline interface is used to continuously accept user input from the command line
  • When a user types a message, it's added to the conversation history and sent to the agent
  • The agent processes the request using the invoke() method with the full conversation history
  • Users can type 'exit', 'quit', or 'bye' to end the chat session gracefully
10

Run the application

main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});
What's happening:
  • We call the main() function to start the application

Complete Code

Here's the complete code to get you started with Ynab and LangChain:

import { Composio } from '@composio/core';
import { LangchainProvider } from '@composio/langchain';
import { MultiServerMCPClient } from "@langchain/mcp-adapters";  
import { createAgent } from "langchain";
import * as readline from 'readline';
import 'dotenv/config';

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.COMPOSIO_USER_ID;

if (!composioApiKey) throw new Error('COMPOSIO_API_KEY is not set');
if (!userId) throw new Error('COMPOSIO_USER_ID is not set');

async function main() {
    const composio = new Composio({
        apiKey: composioApiKey as string,
        provider: new LangchainProvider()
    });

    const session = await composio.create(
        userId as string,
        {
            toolkits: ['ynab']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "ynab-agent": {
            transport: "http",
            url: url,
            headers: {
                "x-api-key": process.env.COMPOSIO_API_KEY
            }
        }
    });
    
    const tools = await client.getTools();
  
    const agent = createAgent({ model: "gpt-5", tools });
    
    let conversationHistory: any[] = [];
    
    console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
    console.log("Ask any Ynab related question or task to the agent.\n");
    
    const rl = readline.createInterface({
        input: process.stdin,
        output: process.stdout,
        prompt: 'You: '
    });

    rl.prompt();

    rl.on('line', async (userInput: string) => {
        const trimmedInput = userInput.trim();
        
        if (['exit', 'quit', 'bye'].includes(trimmedInput.toLowerCase())) {
            console.log("\nGoodbye!");
            rl.close();
            process.exit(0);
        }
        
        if (!trimmedInput) {
            rl.prompt();
            return;
        }
        
        conversationHistory.push({ role: "user", content: trimmedInput });
        console.log("\nAgent is thinking...\n");
        
        const response = await agent.invoke({ messages: conversationHistory });
        conversationHistory = response.messages;
        
        const finalResponse = response.messages[response.messages.length - 1]?.content;
        console.log(`Agent: ${finalResponse}\n`);
        
        rl.prompt();
    });

    rl.on('close', () => {
        console.log('\nSession ended.');
        process.exit(0);
    });
}

main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});

Conclusion

You've successfully built a LangChain agent that can interact with Ynab through Composio's Tool Router.

Key features of this implementation:

  • Dynamic tool loading through Composio's Tool Router
  • Conversation history maintenance for context-aware responses
  • Async Python provides clean, efficient execution of agent workflows
You can extend this further by adding error handling, implementing specific business logic, or integrating additional Composio toolkits to create multi-app workflows.
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.

FRAMEWORKS

How to build Ynab MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Ynab MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Ynab MCP with Claude Agent SDK

Claude Code logo

Claude Code

Use Ynab MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Ynab MCP with Claude Cowork

Codex logo

Codex

Use Ynab MCP with Codex

OpenClaw logo

OpenClaw

Use Ynab MCP with OpenClaw

Hermes logo

Hermes

Use Ynab MCP with Hermes

CLI logo

CLI

Use Ynab MCP with CLI

Google ADK logo

Google ADK

Use Ynab MCP with Google ADK

Vercel AI SDK logo

Vercel AI SDK

Use Ynab MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Ynab MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Ynab MCP with LlamaIndex

CrewAI logo

CrewAI

Use Ynab MCP with CrewAI

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. LangChain 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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