How to integrate Proabono MCP with LangChain

This guide walks you through connecting Proabono to LangChain using the Composio tool router. By the end, you'll have a working Proabono agent that can list all active subscriptions for a customer, create a new subscription for acme corp, show overdue invoices for a specific customer through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Proabono account through Composio's Proabono MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Basic

Proabono is a smart subscription management platform that automates billing and recurring payments. It streamlines your subscription operations and customer lifecycle.

67 Tools

Introduction

This guide walks you through connecting Proabono to LangChain using the Composio tool router. By the end, you'll have a working Proabono agent that can list all active subscriptions for a customer, create a new subscription for acme corp, show overdue invoices for a specific customer through natural language commands.

This guide will help you understand how to give your LangChain agent real control over a Proabono account through Composio's Proabono MCP server.

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

Also integrate Proabono with

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Connect your Proabono project to Composio
  • Create a Tool Router MCP session for Proabono
  • Initialize an MCP client and retrieve Proabono tools
  • Build a LangChain agent that can interact with Proabono
  • 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 Proabono MCP server, and what's possible with it?

The Proabono MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Proabono account. It provides structured and secure access so your agent can perform Proabono operations on your behalf.

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 Proabono 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 Proabono 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: ['proabono']
    }
);

const url = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Proabono 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 Proabono tools as needed
8

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "proabono-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 Proabono MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • getTools() retrieves all available Proabono 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 Proabono 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 Proabono 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: ['proabono']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "proabono-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 Proabono 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 Proabono 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 Proabono action and event your agent gets out of the box.

Anonymize Customer

Tool to anonymize a customer for GDPR compliance.

Bill Customer

Tool to trigger billing for a customer.

Create Customer

Tool to create or declare a customer in ProAbono via the Backoffice API.

Create Feature

Tool to create a new feature in ProAbono via the Backoffice API.

Delete Customer

Tool to delete a customer from ProAbono by ID.

Delete Offer

Tool to delete an offer from ProAbono by ID.

Delete Pricing Table

Tool to delete a pricing table from ProAbono by its ID.

Delete Pricing Table Offer

Tool to delete a pricing table offer via the ProAbono Backoffice API.

Delete Subscription Discount

Tool to delete a subscription discount via the Backoffice API.

Enable Webhook

Tool to enable a webhook in ProAbono via the Notification API.

Get Customer by ID

Tool to retrieve a single customer by ID from ProAbono Backoffice API.

Get Customer Billing Address

Tool to retrieve a customer's billing address via the Backoffice API.

Get Customer Billing Address by Reference

Tool to retrieve the billing address for a customer by reference from ProAbono API.

Get Customer by Reference

Tool to retrieve a customer by their reference identifier from ProAbono API.

Get Customer Payment Settings

Tool to retrieve customer payment settings via the Backoffice API.

Get Discount

Tool to retrieve a discount by ID via the Backoffice API.

Get Feature by ID

Tool to retrieve a feature by ID from ProAbono Backoffice API.

Get Feature by Reference

Tool to retrieve a single feature by its reference from ProAbono API.

Get Invoice

Tool to retrieve a specific invoice or credit note by ID from ProAbono.

Get Offer by ID

Tool to retrieve a single offer by its ID from ProAbono Backoffice API.

Get Subscription by Customer Reference

Tool to retrieve a subscription by customer reference from ProAbono.

Get Subscription Creation Quote

Tool to get a pricing quote for creating a new subscription without actually creating it.

Get Usage Record

Tool to retrieve a single usage record for a specific feature and customer combination from ProAbono.

Get Usages for Customer

Tool to retrieve usage data for customers from ProAbono.

Invalidate Customer

Tool to invalidate a customer by their reference.

Invalidate Customer by ID

Tool to invalidate a customer by their ProAbono internal ID.

List Balance Lines

Tool to list all balance lines from ProAbono.

List Businesses

Tool to list all businesses from ProAbono via the Backoffice API.

List Business Localization

Tool to list localization entries by business from ProAbono via the HostedPages API.

List Customer Moves

Tool to list all customer balance moves via the ProAbono Backoffice API.

List Customers

Tool to list all customers from ProAbono via the Backoffice API.

List Customers by Feature

Tool to list customers that have access to a specific feature via the ProAbono API.

List Discounts

Tool to list all discounts from ProAbono's Backoffice API.

List Features

Tool to list all features via the ProAbono Backoffice API.

List Features (V1)

Tool to retrieve all features from ProAbono API using the /v1/Features endpoint.

List Gateway Accounts

Tool to list payment gateway accounts from ProAbono Backoffice API.

List Gateway Permissions

Tool to list gateway permissions from ProAbono API.

List Gateway Requests

Tool to list gateway requests from ProAbono.

List Gateway Transactions

Tool to list gateway transactions from ProAbono.

List Invoice Lines

Tool to list all invoice lines from ProAbono via the Backoffice API.

List Invoices and Credit Notes

Tool to list all invoices and credit notes from ProAbono Backoffice API.

List Invoices by Customer Reference

Tool to list invoices for a specific customer by their reference identifier from ProAbono API.

List Offers

Tool to list all subscription offers (plans) from ProAbono Backoffice API.

List Payments

Tool to list all payments from ProAbono Backoffice API.

List Pricing Table Offers

Tool to list all pricing table offers via the ProAbono Backoffice API.

List Pricing Tables

Tool to list all pricing tables from ProAbono Backoffice API.

List Segment Localizations

Tool to list localization entries by segment from ProAbono Backoffice API.

List Segments

Tool to list all segments from ProAbono via the Backoffice API.

List Subscription Discounts

Tool to list all subscription discounts via the ProAbono Backoffice API.

List Subscription Features

Tool to list all subscription features via the ProAbono Backoffice API.

List Subscription Periods

Tool to list all subscription periods (billing cycles) from ProAbono Backoffice API.

List Subscriptions

Tool to list all subscriptions from ProAbono via the Backoffice API.

List Subscriptions (V1)

Tool to retrieve all subscriptions from ProAbono API using the /v1/Subscriptions endpoint.

List Tax Profile Exceptions

Tool to list tax profile exceptions from ProAbono Organization API.

List Tax Profiles

Tool to list all tax profiles from ProAbono via the Backoffice API.

List Upgrade Offers

Tool to retrieve offers available to upgrade an existing customer subscription.

List Webhook Notifications

Tool to list webhook notifications from ProAbono via the Notification API.

List Webhooks

Tool to list webhooks from ProAbono Notification API.

Quote Balance Line Creation

Tool to get a pricing quote for creating a balance line (one-time charge or credit).

Revoke Customer Portal Links

Tool to revoke encrypted customer portal links and generate new ones in ProAbono.

Update Business Billing Address

Tool to update business billing address via the Backoffice API.

Update Customer

Tool to update an existing customer in ProAbono via the Backoffice API.

Update Customer Billing Address

Tool to update the billing address for a customer in ProAbono via the API.

Update Customer Payment Settings

Tool to update payment settings for a specific customer in ProAbono.

Update Customer Shipping Address

Tool to update customer shipping address via the Backoffice API.

Update Feature

Tool to update an existing feature in ProAbono via the Backoffice API.

Update Tax Profiles

Tool to update an existing tax profile in ProAbono via the Backoffice API.

FAQ

Frequently asked questions

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

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

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