How to integrate Documenso MCP with LangChain

This guide walks you through connecting Documenso to LangChain using the Composio tool router. By the end, you'll have a working Documenso agent that can send a contract to client for signature, download the latest signed nda document, list all templates for onboarding paperwork through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Documenso account through Composio's Documenso MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Get started for freeGet a demo
Documenso logoDocumenso
Api Key

Documenso is an open-source platform for digital document signing and management. It streamlines sending, tracking, and signing paperwork online—no more manual signatures or printing.

77 Tools

Introduction

This guide walks you through connecting Documenso to LangChain using the Composio tool router. By the end, you'll have a working Documenso agent that can send a contract to client for signature, download the latest signed nda document, list all templates for onboarding paperwork through natural language commands.

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

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

Also integrate Documenso 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 Documenso project to Composio
  • Create a Tool Router MCP session for Documenso
  • Initialize an MCP client and retrieve Documenso tools
  • Build a LangChain agent that can interact with Documenso
  • 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 Documenso MCP server, and what's possible with it?

The Documenso MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Documenso account. It provides structured and secure access to your electronic signature workflows, so your agent can create documents, distribute them for signing, manage templates, and download signed files automatically on your behalf.

  • Automated document creation and duplication: Prompt your agent to generate new documents or make exact copies of existing ones for rapid workflow setup.
  • Seamless document distribution for signatures: Let your agent send documents to one or more recipients, kicking off secure e-signature flows without manual intervention.
  • Template management and retrieval: Ask your agent to list, fetch, or delete document templates, keeping your signing processes organized and up-to-date.
  • Download and access signed documents: Have your agent retrieve finalized, signed PDFs automatically for seamless archiving or sharing.
  • Streamlined document organization: Direct your agent to move documents between personal and team spaces, or remove unnecessary fields to keep everything tidy and current.

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 Documenso 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 Documenso 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: ['documenso']
    }
);

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

Configure the agent with the MCP URL

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

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

Create Document Beta

Tool to create a new document using the beta endpoint that returns a presigned URL for file upload.

Create Document Field

Tool to create a single field for a document.

Create Document Fields (Bulk)

Tool to create multiple fields on a document in a single operation.

Create Document Recipient

Tool to create a single recipient for a document.

Create Document Recipients Bulk

Tool to create multiple recipients for a document at once.

Create Embedding Presign Token V2 Beta

Create a presign token for Documenso embedded authoring sessions.

Create Envelope

Tool to create a new envelope in Documenso.

Create Envelope Attachment

Create a new attachment for an envelope in Documenso.

Create Envelope Items Bulk

Tool to create multiple items for an envelope with optional file attachments.

Create Envelope Recipients Bulk

Tool to create multiple recipients for an envelope in bulk.

Create Folder

Create a new folder in Documenso to organize documents or templates.

Create Template Beta

Tool to create a new template using the beta endpoint that returns a presigned URL for file upload.

Create Template Field

Tool to create a single field for a template.

Create Template Fields (Bulk)

Tool to create multiple fields on a template in a single operation.

Create Template Recipient

Tool to create a single recipient for a template.

Create Template Recipients Bulk

Tool to create multiple recipients for a template at once.

Delete Document

Tool to delete a document.

Delete Document Attachment

Tool to delete an attachment from a document.

Delete Document Field

Tool to delete a single document field by ID.

Delete Document Fields

Tool to delete one or more fields from a document.

Delete Document Recipient

Tool to delete a recipient from a document.

Delete Envelope

Tool to permanently delete an envelope.

Delete Envelope Attachment

Tool to delete an attachment from an envelope.

Delete Envelope Field

Tool to delete a field from an envelope.

Delete Envelope Item

Tool to delete an item from an envelope.

Delete Envelope Recipient

Tool to delete a recipient from an envelope.

Delete Folder

Tool to permanently delete a folder.

Delete Template

Permanently delete a template by its ID.

Delete Template Direct Link

Delete a direct link for a template.

Delete Template Recipient

Tool to delete a recipient from a template.

Delete Template V2

Tool to permanently delete a template using the v2 API.

Distribute Document V2

Tool to distribute a document for signing.

Distribute Envelope

Tool to distribute an envelope to recipients for signing.

Download Envelope Item

Download an envelope item as PDF.

Download Signed Document

Download a completed/signed document as PDF.

Duplicate Document V2

Tool to duplicate a document.

Duplicate Envelope V2

Tool to duplicate an envelope with all its settings.

Duplicate Template

Tool to duplicate a template with all its settings.

Find Documents

Find documents based on search criteria with filtering and pagination.

Find Documents V2

Retrieve a paginated list of documents with optional filtering and sorting.

Find Envelopes

Tool to find envelopes based on search criteria, filters, and pagination.

Find Folders

Tool to find folders based on search criteria and filters.

Find Templates

Retrieve a paginated list of templates with optional filtering and search.

Get Document By ID

Retrieve complete information about a document by its ID.

Get Document Field

Tool to retrieve a document field by its ID.

Get Document Recipient

Tool to retrieve detailed information about a document recipient by their ID.

Get Documents By IDs

Retrieve multiple documents by their IDs in a single request.

Get Envelope Attachment

Tool to find all attachments for a specific envelope.

Get Envelope Audit Log

Tool to retrieve audit logs for an envelope.

Get Envelope By ID

Retrieve complete information about an envelope by its ID.

Get Envelope Field

Tool to fetch an envelope field by ID.

Get Envelope Recipient

Tool to retrieve detailed information about an envelope recipient by their ID.

Get Envelopes By IDs

Tool to retrieve multiple envelopes by their IDs.

Get Template By ID

Retrieve complete information about a template by its ID.

Get Template Field

Tool to fetch a template field by ID.

Get Template Recipient

Tool to retrieve detailed information about a template recipient by their ID.

Get Templates By IDs

Retrieve multiple templates by their IDs in a single request.

List Templates

Tool to list templates.

Move Document V2

Tool to move a document to a team.

Redistribute Document V2

Re-send signing request emails to specified recipients of a document.

Redistribute Envelope

Tool to redistribute an envelope to recipients who have not actioned it.

Remove Team Member V1

Remove a member from a Documenso team.

Update Document Attachment

Tool to update an existing document attachment.

Update Document Field

Tool to update a single document field's properties in Documenso v2 API.

Update Document Fields Bulk

Tool to update multiple document fields in a single operation.

Update Document Recipient V2

Tool to update a document recipient using the v2 API.

Update Document V2

Update document properties like title, visibility, and signing settings.

Update Envelope

Update envelope properties like title, visibility, and signing settings.

Update Envelope Attachment

Tool to update an existing envelope attachment.

Update Envelope Fields Bulk

Tool to update multiple envelope fields in a single request.

Update Envelope Items Bulk

Tool to update multiple envelope items in a single request.

Update Folder

Update properties of an existing folder including name, pinned status, parent folder, and visibility.

Update Template

Update template properties like title, visibility, and signing settings.

Update Template Fields Bulk

Tool to update multiple template fields in a single operation.

Update Template Recipient

Tool to update a template recipient.

Update Template Recipients Bulk

Tool to update multiple template recipients in a single API call.

Use Template (v2-beta)

Tool to create a document from a template.

FRAMEWORKS

How to build Documenso MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Documenso MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Documenso MCP with Claude Agent SDK

Claude Code logo

Claude Code

Use Documenso MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Documenso MCP with Claude Cowork

Codex logo

Codex

Use Documenso MCP with Codex

OpenClaw logo

OpenClaw

Use Documenso MCP with OpenClaw

Hermes logo

Hermes

Use Documenso MCP with Hermes

CLI logo

CLI

Use Documenso MCP with CLI

Google ADK logo

Google ADK

Use Documenso MCP with Google ADK

Vercel AI SDK logo

Vercel AI SDK

Use Documenso MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Documenso MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Documenso MCP with LlamaIndex

CrewAI logo

CrewAI

Use Documenso MCP with CrewAI

FAQ

Frequently asked questions

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

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

Start with Documenso.It takes 30 seconds.

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

Start building
Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREEBOOK A DEMO
agent.aiZoomLettaGleanHubSpotAWSWabi

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
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
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
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
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
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
Jerome Leclanche
Co-Founder, Ingram Technologies