How to integrate Heygen MCP with LangChain

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Introduction

This guide walks you through connecting Heygen to LangChain using the Composio tool router. By the end, you'll have a working Heygen agent that can create a talking photo from my selfie, add new contacts to my video project, list all available streaming avatars for today, fetch details of my latest personalized video project through natural language commands.

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

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

TL;DR

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

The Heygen MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Heygen account. It provides structured and secure access to your Heygen video platform, so your agent can perform actions like creating talking photos, managing video assets, personalizing video projects, and controlling streaming avatars on your behalf.

  • AI-powered video asset creation: Add new avatars, backgrounds, or other content elements directly into your Heygen library for use in video generation workflows.
  • Personalized video project management: Let your agent add contacts to personalized video projects and fetch detailed project information to streamline large-scale video personalization efforts.
  • Dynamic talking photo generation: Instantly create engaging talking photos from uploaded images, transforming static pictures into interactive, speaking content for marketing or educational use.
  • Real-time avatar streaming control: Retrieve a list of streaming avatars, generate streaming tokens, and manage live avatar sessions—including interrupting or monitoring ongoing streams for responsive, interactive experiences.
  • Audience insights and analytics: Fetch detailed audience engagement and preference data for personalized video campaigns, helping you optimize your content and targeting strategies.

Supported Tools & Triggers

Tools
Add new assetCreates a new asset in the heygen platform.
Add contact to personalized video projectThis endpoint allows you to add one or more contacts to a specific personalized video project in the heygen platform.
Retrieve audience video detailsRetrieves detailed information about the audience for personalized videos.
Fetch personalized video project detailRetrieves detailed information about a specific personalized video project in the heygen platform.
Post talking photo binary imageCreates a talking photo by processing an uploaded image file.
List streaming avatarsRetrieves a list of available avatars for streaming purposes in the heygen platform.
Create streaming token with expiryCreates a new streaming token for use with heygen's real-time avatar and voice chat services.
Post streaming ice candidatesThis endpoint is used to submit ice (interactive connectivity establishment) candidate information for a specific streaming session in the heygen platform.
Interrupt streaming sessionInterrupts an ongoing streaming session with an interactive avatar.
Retrieve streaming listRetrieves a list of active or available streaming sessions or content within the heygen platform.
Set streaming quality endpointInitiates a new streaming session with heygen, allowing users to start an avatar-based stream with specified quality settings.
Start streaming sessionInitiates a new streaming session for real-time communication in the heygen platform.
Stop streaming sessionThe streaming.
Post streaming task sessionThe streamingtask endpoint initiates a real-time speaking task for an ai-driven avatar within an active streaming session.
List avatars endpointRetrieves a list of available avatars from the heygen platform.
List talking photo entriesRetrieves a list of talking photos created using the heygen platform.
Delete videoThe video.
List videosRetrieves a list of videos associated with the user's account on the heygen platform.
Retrieve video statusRetrieves the current status of a video in the heygen platform.
List voice endpointsRetrieves a comprehensive list of all available voices in the heygen platform.
Add webhook endpointAdds a new webhook endpoint to receive real-time notifications for specified heygen events.
Delete webhook endpointDeletes a specific webhook endpoint from the heygen system.
List webhook endpointsRetrieves a list of all webhook endpoints configured for your heygen account.
List webhooksRetrieves a list of all webhooks configured for your heygen account.
Retrieve avatars collectionRetrieves a list of available avatars from the heygen platform.
Delete talking photo by idDeletes a specific talking photo from the heygen platform using its unique identifier.
Generate video template with variablesThis endpoint generates a customized video based on a pre-existing template using heygen's ai-driven platform.
Get template by idRetrieves a specific template from the heygen platform using its unique identifier.
Retrieve all templatesRetrieves a list of available avatar templates from the heygen platform.
Retrieve user remaining quotaRetrieves the current remaining quota for the authenticated user on the heygen platform.
Generate video with inputsGenerates a customized video using heygen's ai-driven platform.
Post video translate requestThe translatevideo endpoint enables the translation of video content from one language to another.
Retrieve video translation by idRetrieves the current status of a video translation job in the heygen platform.
Retrieve video translation target languagesRetrieves a list of all available target languages supported by heygen's video translation feature.
List available voicesRetrieves a list of available voice models and options that can be used with heygen's ai-driven video creation platform.

What is the Composio tool router, and how does it fit here?

What is Tool Router?

Composio's Tool Router 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 Tool Router

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Tool Router works

The Tool Router 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

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

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.

Install dependencies

pip install composio-langchain langchain-mcp-adapters langchain python-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 is the core agent framework
  • python-dotenv loads environment variables

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

Import dependencies

from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain.agents import create_agent
from dotenv import load_dotenv
from composio import Composio
import asyncio
import os

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

Initialize Composio client

async def main():
    composio = Composio(api_key=os.getenv("COMPOSIO_API_KEY"))

    if not os.getenv("COMPOSIO_API_KEY"):
        raise ValueError("COMPOSIO_API_KEY is not set")
    if not os.getenv("COMPOSIO_USER_ID"):
        raise ValueError("COMPOSIO_USER_ID is not set")
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 Heygen tools
  • Validating that COMPOSIO_USER_ID is also set before proceeding

Create a Tool Router session

# Create Tool Router session for Heygen
session = composio.create(
    user_id=os.getenv("COMPOSIO_USER_ID"),
    toolkits=['heygen']
)

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

Configure the agent with the MCP URL

client = MultiServerMCPClient({
    "heygen-agent": {
        "transport": "streamable_http",
        "url": session.mcp.url,
        "headers": {
            "x-api-key": os.getenv("COMPOSIO_API_KEY")
        }
    }
})

tools = await client.get_tools()

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

Set up interactive chat interface

conversation_history = []

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

while True:
    user_input = input("You: ").strip()

    if user_input.lower() in ['exit', 'quit', 'bye']:
        print("\nGoodbye!")
        break

    if not user_input:
        continue

    conversation_history.append({"role": "user", "content": user_input})
    print("\nAgent is thinking...\n")

    response = await agent.ainvoke({"messages": conversation_history})
    conversation_history = response['messages']
    final_response = response['messages'][-1].content
    print(f"Agent: {final_response}\n")
What's happening:
  • We initialize an empty conversation_history list to maintain context across interactions
  • A while loop continuously accepts 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 ainvoke() method with the full conversation history
  • Users can type 'exit', 'quit', or 'bye' to end the chat session gracefully

Run the application

if __name__ == "__main__":
    asyncio.run(main())
What's happening:
  • We call the main() function using asyncio.run() to start the application

Complete Code

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

from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain.agents import create_agent
from dotenv import load_dotenv
from composio import Composio
import asyncio
import os

load_dotenv()

async def main():
    composio = Composio(api_key=os.getenv("COMPOSIO_API_KEY"))
    
    if not os.getenv("COMPOSIO_API_KEY"):
        raise ValueError("COMPOSIO_API_KEY is not set")
    if not os.getenv("COMPOSIO_USER_ID"):
        raise ValueError("COMPOSIO_USER_ID is not set")
    
    session = composio.create(
        user_id=os.getenv("COMPOSIO_USER_ID"),
        toolkits=['heygen']
    )

    url = session.mcp.url
    
    client = MultiServerMCPClient({
        "heygen-agent": {
            "transport": "streamable_http",
            "url": url,
            "headers": {
                "x-api-key": os.getenv("COMPOSIO_API_KEY")
            }
        }
    })
    
    tools = await client.get_tools()
  
    agent = create_agent("gpt-5", tools)
    
    conversation_history = []
    
    print("Chat started! Type 'exit' or 'quit' to end the conversation.\n")
    print("Ask any Heygen related question or task to the agent.\n")
    
    while True:
        user_input = input("You: ").strip()
        
        if user_input.lower() in ['exit', 'quit', 'bye']:
            print("\nGoodbye!")
            break
        
        if not user_input:
            continue
        
        conversation_history.append({"role": "user", "content": user_input})
        print("\nAgent is thinking...\n")
        
        response = await agent.ainvoke({"messages": conversation_history})
        conversation_history = response['messages']
        final_response = response['messages'][-1].content
        print(f"Agent: {final_response}\n")

if __name__ == "__main__":
    asyncio.run(main())

Conclusion

You've successfully built a LangChain agent that can interact with Heygen 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.

How to build Heygen MCP Agent with another framework

FAQ

What are the differences in Tool Router MCP and Heygen MCP?

With a standalone Heygen MCP server, the agents and LLMs can only access a fixed set of Heygen tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Heygen and many other apps based on the task at hand, all through a single MCP endpoint.

Can I use Tool Router MCP with LangChain?

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 Heygen tools.

Can I manage the permissions and scopes for Heygen while using Tool Router?

Yes, absolutely. You can configure which Heygen 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.

How safe is my data with Composio Tool Router?

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 Heygen data and credentials are handled as safely as possible.

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