How to integrate Rentman MCP with LangChain

This guide walks you through connecting Rentman to LangChain using the Composio tool router. By the end, you'll have a working Rentman agent that can list all crew assignments for this week, show available equipment for project 1234, create new project booking for next month through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Rentman account through Composio's Rentman MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Rentman logoRentman
Api Key

Rentman is a platform for managing crew, equipment, and projects in one place. It streamlines scheduling, resource allocation, and project coordination for event professionals.

130 Tools

Introduction

This guide walks you through connecting Rentman to LangChain using the Composio tool router. By the end, you'll have a working Rentman agent that can list all crew assignments for this week, show available equipment for project 1234, create new project booking for next month through natural language commands.

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

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

Also integrate Rentman with

TL;DR

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

The Rentman MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Rentman account. It provides structured and secure access so your agent can perform Rentman 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 Rentman 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 Rentman 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: ['rentman']
    }
);

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

Configure the agent with the MCP URL

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

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

Delete Appointment

Tool to delete an appointment by its unique ID.

Delete Appointmentcrew Item

Tool to delete an appointmentcrew item by its numeric ID.

Delete Contact

Tool to delete a contact by its ID.

Delete contact person

Tool to delete a contact person from Rentman by their numeric ID.

Delete Cost Item

Tool to delete a cost item in Rentman by its numeric ID.

Delete Crew Availability

Tool to delete a crew availability item by its ID.

Delete Project Request

Tool to delete a project request by its ID.

Delete Project Request Equipment Item

Tool to delete a project request equipment item by its ID.

Delete Time Registration

Tool to delete a time registration item in Rentman by its numeric ID.

Get Accessories Collection

Tool to retrieve a collection of accessories from Rentman.

Get Appointment Crew

Tool to retrieve the linked crew members for a specific appointment.

Get Appointmentcrew Collection

Tool to retrieve appointmentcrew collection from Rentman.

Get Appointments Collection

Tool to retrieve a collection of appointments from Rentman.

Get Contact Contactpersons

Tool to retrieve all contactpersons linked to a specific contact in Rentman.

Get Contact File Folders

Tool to get file folders linked to a contact.

Get Contact Files

Tool to get files linked to a contact.

Get Contact Person File Folders

Tool to retrieve file folders linked to a contact person in Rentman.

Get Contact Person Files

Tool to retrieve files linked to a contact person in Rentman.

Get Contact Persons

Tool to retrieve the collection of contact persons from Rentman.

Get Contacts Collection

Tool to retrieve a collection of contacts from Rentman.

Get contract invoicelines

Retrieves invoicelines linked to a specific contract.

Get Contract Files

Tool to retrieve files linked to a specific contract.

Get Contracts Collection

Tool to retrieve a collection of contracts from Rentman.

Get Costs Collection

Tool to retrieve costs collection from Rentman.

Get Crew Member Appointments

Tool to retrieve appointments for a specific crew member.

Get Crew Availability

Tool to retrieve crew availability records for a specific crew member in Rentman.

Get Crew Availability Collection

Tool to retrieve crew availability collection from Rentman.

Get Crew Collection

Tool to retrieve crew collection from Rentman.

Get Crew File Folders

Tool to retrieve file folders linked to a crew member.

Get Crew Files

Tool to retrieve files linked to a crew member.

Get Crew Member

Tool to retrieve a crew member item by ID from Rentman.

Get Crewrates Collection

Tool to retrieve crewrates collection from Rentman.

Get Crew Rates

Tool to get crew rates linked collection for a specific crew member.

Get Equipment Accessories

Tool to get accessories linked to a specific equipment item.

Get equipment collection

Tool to get the equipment collection from Rentman.

Get Equipment File Folders

Tool to get file folders linked to equipment.

Get Equipment Files

Tool to get files linked to equipment.

Get Equipment Repairs

Tool to retrieve repairs linked to a specific equipment item.

Get Equipment Serial Numbers

Tool to retrieve serial numbers linked to a specific equipment item.

Get Equipment Sets Content Collection

Tool to retrieve the equipment sets content collection from Rentman.

Get Equipment Sets Content

Tool to get equipment sets content linked collection for a specific equipment item.

Get Equipment Stockmovements

Tool to get stockmovements linked collection for a specific equipment item.

Get Files Collection

Tool to retrieve files collection from Rentman.

Get Folder Item

Tool to retrieve a folder item by ID from Rentman.

Get Folders Collection

Tool to retrieve folders collection from Rentman.

Get Invoice Files

Tool to retrieve files linked to an invoice in Rentman.

Get Invoice Invoicelines

Tool to retrieve invoicelines linked to a specific invoice.

Get Invoice Lines

Tool to retrieve invoicelines collection from Rentman.

Get Invoice Payments

Tool to retrieve payments linked to a specific invoice.

Get Invoices Collection

Tool to retrieve a collection of invoices from Rentman.

Get Ledgercodes Collection

Tool to retrieve ledger codes collection from Rentman.

Get Payments Collection

Tool to retrieve a collection of payments from Rentman.

Get Project Contracts

Tool to retrieve contracts linked to a specific project from Rentman.

Get Project Costs

Tool to retrieve costs linked to a specific project from Rentman.

Get Projectcrew Collection

Tool to retrieve projectcrew collection from Rentman.

Get Project Equipment Collection

Tool to retrieve a collection of project equipment from Rentman.

Get Projectequipmentgroup Collection

Tool to retrieve projectequipmentgroup collection from Rentman.

Get project equipment group project equipment

Tool to get projectequipment linked collection for a specific projectequipmentgroup.

Get Project File Folders

Tool to retrieve file folders linked to a specific project.

Get Project Files

Tool to retrieve files linked to a project.

Get Project Function Group Project Functions

Tool to get project functions linked to a specific project function group in Rentman.

Get Project Function Groups Collection

Tool to retrieve a collection of project function groups from Rentman.

Get Project Function Crew

Tool to get project crew linked to a specific project function.

Get Projectfunction Projectvehicles

Tool to retrieve project vehicles linked to a project function.

Get Projectfunctions Collection

Tool to retrieve a collection of projectfunctions from Rentman.

Get Project Crew

Tool to get project crew custom linked collection for a specific project.

Get Project Equipment

Tool to retrieve all equipment items linked to a specific project in Rentman.

Get project projectequipmentgroup

Tool to get projectequipmentgroup linked collection for a specific project.

Get Project Function Groups For Project

Tool to retrieve project function groups linked to a specific project in Rentman.

Get Project Projectfunctions

Tool to retrieve projectfunctions linked to a specific project.

Get Project Projectvehicles

Tool to retrieve project vehicles linked to a project.

Get Project Quotes

Tool to retrieve quotes linked to a project.

Get Project Request Equipment

Tool to retrieve projectrequestequipment linked to a specific project request in Rentman.

Get Project Request Equipment Collection

Tool to retrieve project request equipment collection from Rentman.

Get Project Requests Collection

Tool to retrieve a collection of project requests from Rentman.

Get Projects Collection

Tool to retrieve a collection of projects from Rentman.

Get Project Subprojects

Tool to retrieve subprojects linked to a specific project from Rentman.

Get Projecttypes Collection

Tool to retrieve a collection of project types from Rentman.

Get Projectvehicles Collection

Tool to retrieve projectvehicles collection from Rentman.

Get Quote Files

Tool to get files linked to a quote.

Get quote invoicelines

Retrieves invoicelines linked to a specific quote.

Get Quotes Collection

Tool to retrieve a collection of quotes from Rentman.

Get Ratefactors Collection

Tool to retrieve a collection of ratefactors from Rentman.

Get Rate Ratefactors

Tool to retrieve the ratefactors custom linked collection for a specific rate.

Get Rates Collection

Tool to retrieve rates collection from Rentman.

Get Repair File Folders

Tool to get file folders linked to a repair.

Get Repair Files

Tool to get files linked to a repair.

Get Repairs Collection

Tool to retrieve a collection of repairs from Rentman.

Get Serial Number File Folders

Tool to get file folders linked to a serial number.

Get Serial Number Files

Tool to get files linked to a serial number.

Get Serialnumbers Collection

Tool to retrieve a collection of serialnumbers from Rentman.

Get Statuses Collection

Tool to retrieve a collection of statuses from Rentman.

Get Stocklocations Collection

Tool to retrieve stock locations collection from Rentman.

Get Stockmovements Collection

Tool to retrieve the stock movements collection from Rentman.

Get Subproject File Folders

Tool to get file folders linked to a subproject.

Get Subproject Project Crew

Tool to get project crew custom linked collection for a specific subproject.

Get Subproject Project Equipment

Tool to retrieve project equipment collection from a specific subproject in Rentman.

Get subproject projectequipmentgroup

Tool to get projectequipmentgroup linked collection for a specific subproject.

Get Project Function Groups For Subproject

Tool to retrieve project function groups linked to a specific subproject in Rentman.

Get Subproject Projectvehicles

Tool to retrieve project vehicles linked to a subproject.

Get Subprojects Collection

Tool to retrieve subprojects collection from Rentman.

Get Subrental Equipment Collection

Tool to retrieve a collection of subrental equipment items from Rentman.

Get Subrental Equipment Group

Tool to get subrental equipment group custom linked collection from Rentman.

Get Subrental Equipment Group Collection

Tool to retrieve the complete collection of subrental equipment groups from Rentman.

Get subrental equipment group subrental equipment

Tool to get subrentalequipment custom linked collection for a specific subrentalequipmentgroup.

Get Subrental File Folders

Tool to get file folders linked to a subrental.

Get Subrental Files

Tool to get files linked to a subrental.

Get Subrentals Collection

Tool to get subrentals collection from Rentman.

Get Subrental Subrentalequipment

Tool to retrieve subrentalequipment linked to a specific subrental in Rentman.

Get Tax Classes Collection

Tool to retrieve a collection of tax classes from Rentman.

Get Timeregistration Activities

Tool to retrieve all timeregistrationactivities linked to a specific timeregistration in Rentman.

Get Timeregistration Activities Collection

Tool to retrieve a collection of timeregistration activities from Rentman.

Get Timeregistration Collection

Tool to retrieve a collection of timeregistrations from Rentman.

Get Time Registration Files

Tool to get files linked to a time registration.

Get Vehicle File Folders

Tool to get file folders linked to a vehicle.

Get Vehicle Files

Tool to get files linked to a vehicle.

Get Vehicles Collection

Tool to retrieve a collection of vehicles from Rentman.

List Actualcontent

Tool to get actualcontent collection from Rentman.

List Equipmentassignedserials Collection

Tool to retrieve serial numbers assigned to serialized physical combinations from Rentman.

List Factorgroups

Tool to retrieve factorgroups collection from Rentman.

List Factorgroups Factors

Tool to retrieve the factors collection for a specific factorgroup.

List Factors

Tool to retrieve a collection of factors from Rentman.

List File Folders

Tool to retrieve file folders collection from Rentman.

List Leave Mutations

Tool to retrieve leave mutations collection from Rentman.

List Leave Requests

Tool to retrieve leave requests collection from Rentman.

List Leave Request Timeregistration

Tool to get timeregistration collection for a specific leave request.

List Leave Types

Tool to retrieve leave types collection from Rentman.

List Serialnumber Actualcontent

Tool to retrieve the actualcontent collection for a specific serialnumber item.

List Serialnumber Equipment Assigned Serials

Tool to retrieve equipmentassignedserials collection for a specific serialnumber item.

List Stocklocations Vehicles

Tool to retrieve vehicles collection for a stocklocation.

FAQ

Frequently asked questions

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

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

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