How to integrate Happy scribe MCP with LangChain

This guide walks you through connecting Happy scribe to LangChain using the Composio tool router. By the end, you'll have a working Happy scribe agent that can transcribe this podcast episode to text, generate subtitles for uploaded video file, export subtitles in srt format for review through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Happy scribe account through Composio's Happy scribe MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Happy scribe logoHappy scribe
Api Key

Happy Scribe is an automatic transcription service that converts audio and video files into accurate text. It lets you quickly generate transcripts and subtitles, saving you hours of manual work.

19 Tools

Introduction

This guide walks you through connecting Happy scribe to LangChain using the Composio tool router. By the end, you'll have a working Happy scribe agent that can transcribe this podcast episode to text, generate subtitles for uploaded video file, export subtitles in srt format for review through natural language commands.

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

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

Also integrate Happy scribe with

TL;DR

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

The Happy Scribe MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Happy Scribe account. It provides structured and secure access to your transcription and subtitle services, so your agent can perform actions like starting new transcriptions, generating subtitles, exporting files, and managing your transcription jobs on your behalf.

  • Automated transcription creation: Instantly start new transcription jobs from audio or video files using a simple agent command.
  • Subtitle generation for videos: Have your agent generate accurate subtitles for your video content for accessibility and localization.
  • Export and download transcripts or subtitles: Let your agent export completed transcriptions or subtitles in various formats for easy distribution.
  • Account and usage monitoring: Retrieve account details, subscription status, and API usage statistics to keep tabs on your service limits.
  • Transcription management and cleanup: Direct your agent to delete completed or unwanted transcription jobs, keeping your workspace organized.

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 Happy scribe 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 Happy scribe 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: ['happy_scribe']
    }
);

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

Configure the agent with the MCP URL

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

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

Create Subtitle

Create subtitles for a video file using Happy Scribe's automatic transcription service.

Create Translation Task

Creates an AI-powered translation task to translate an existing transcription into another language.

Delete Transcription

Tool to delete a transcription job.

Delete Webhook

Deletes a webhook by its ID.

Get Account Details

Tool to retrieve details about your account, including subscription status and usage statistics.

Get Supported Languages

Retrieve the list of supported language codes for Happy Scribe transcription services.

Get API Rate Limit

Get Happy Scribe API rate limit information.

Get Signed Upload URL

Tool to get a signed URL for uploading a file to Happy Scribe's S3 storage.

Confirm Order

Tool to confirm a pending order.

Create Translation Order

Tool to create a translation order from an existing transcription.

Export Transcription

Creates an export job to download transcription content in various formats.

Get API Version

Tool to retrieve current API version and check for updates.

Get Error Codes

Returns a list of HTTP error codes used by the Happy Scribe API along with their descriptions.

Get Supported Formats

Tool to retrieve supported file formats.

Get Transcription Details

Tool to retrieve details and status of a specific transcription job.

Get Webhooks

Tool to retrieve webhooks configured for your account.

Retrieve Export

Tool to retrieve information about a specific export.

List Transcriptions

Retrieves a paginated list of transcription jobs for a Happy Scribe organization.

Retrieve Order

Retrieve details of a Happy Scribe order by its ID.

FAQ

Frequently asked questions

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

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

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