# How to integrate Castingwords MCP with LangChain

```json
{
  "title": "How to integrate Castingwords MCP with LangChain",
  "toolkit": "Castingwords",
  "toolkit_slug": "castingwords",
  "framework": "LangChain",
  "framework_slug": "langchain",
  "url": "https://composio.dev/toolkits/castingwords/framework/langchain",
  "markdown_url": "https://composio.dev/toolkits/castingwords/framework/langchain.md",
  "updated_at": "2026-05-12T10:05:47.733Z"
}
```

## Introduction

This guide walks you through connecting Castingwords to LangChain using the Composio tool router. By the end, you'll have a working Castingwords agent that can transcribe this podcast episode from its url, check your available transcription balance now, order timestamps upgrade for file 12345 through natural language commands.
This guide will help you understand how to give your LangChain agent real control over a Castingwords account through Composio's Castingwords MCP server.
Before we dive in, let's take a quick look at the key ideas and tools involved.

## Also integrate Castingwords with

- [OpenAI Agents SDK](https://composio.dev/toolkits/castingwords/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/castingwords/framework/claude-agents-sdk)
- [Claude Code](https://composio.dev/toolkits/castingwords/framework/claude-code)
- [Claude Cowork](https://composio.dev/toolkits/castingwords/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/castingwords/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/castingwords/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/castingwords/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/castingwords/framework/cli)
- [Google ADK](https://composio.dev/toolkits/castingwords/framework/google-adk)
- [Vercel AI SDK](https://composio.dev/toolkits/castingwords/framework/ai-sdk)
- [Mastra AI](https://composio.dev/toolkits/castingwords/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/castingwords/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/castingwords/framework/crew-ai)

## TL;DR

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

The Castingwords MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Castingwords account. It provides structured and secure access to transcription services, so your agent can place new orders, check account balances, manage webhooks, and upgrade or refund audio files on your behalf.
- Seamless transcription ordering: Let your agent initiate new audio or video transcription jobs using just a media URL—no manual uploads needed.
- Account balance and SKU checks: Effortlessly retrieve your prepay balance or list available transcription services and pricing before placing orders.
- Webhook management and testing: Register, verify, and test webhooks to automatically receive transcript completion notifications in your own systems.
- Transcription order management: Upgrade completed jobs (for example, to add timestamps), or cancel and refund audio files before work begins if needed.

## Supported Tools

| Tool slug | Name | Description |
|---|---|---|
| `CASTINGWORDS_CANCEL_AUDIOFILE` | Cancel and Refund Audio File | Tool to cancel an ordered audio file and issue a refund if applicable. Use when no transcription work has been done on the file (Pre-Processing, Audio Processing, Error states). |
| `CASTINGWORDS_GET_PREPAY_BALANCE` | Get Prepay Balance | Tool to retrieve the current prepay balance for the account. Use when you need to check available funds before placing new transcription orders. |
| `CASTINGWORDS_GET_TRANSCRIPT` | Get Transcript | Tool to retrieve the transcript for a given audiofile in the requested format (txt, doc, rtf, or html). Use after a transcription order has been completed. |
| `CASTINGWORDS_GET_WEBHOOK` | Get registered webhook URL | Tool to retrieve the currently registered webhook URL for account notifications. Use when you need to verify your webhook setup. |
| `CASTINGWORDS_ORDER_TRANSCRIPT` | Order Transcript | Create a transcription order for audio/video files at publicly accessible URLs. Returns order ID and audiofile IDs for tracking. Requires prepaid balance for non-test orders. Use test=true to validate URLs without charges. |
| `CASTINGWORDS_ORDER_UPGRADES` | Order Upgrades | Tool to order an upgrade for a specific audio file. Use after transcription is complete to add items like timestamps or extra editing. Example: 'Order timestamps for file 12345'. |
| `CASTINGWORDS_REGISTER_WEBHOOK` | Register Webhook | Registers a webhook URL to receive CastingWords event notifications. When events occur (e.g., transcript completion, refund issued, difficult audio), CastingWords will POST to your registered URL with event details. Use CASTINGWORDS_GET_WEBHOOK to verify the current webhook, and CASTINGWORDS_TEST_WEBHOOK to test notifications. |
| `CASTINGWORDS_SKU_LIST` | List Available SKUs | Retrieves all available CastingWords transcription service SKUs with pricing. Use this tool to discover available services (transcription, captions, etc.) and their per-minute prices before placing an order. Returns SKU codes needed for order placement. |
| `CASTINGWORDS_TEST_WEBHOOK` | Test Webhook Call | Tool to request a test webhook call for a specific event type. Use after registering a webhook URL to ensure webhook notifications are functioning properly. |

## Supported Triggers

None listed.

## Creating MCP Server - Stand-alone vs Composio SDK

The Castingwords MCP server is an implementation of the Model Context Protocol that connects your AI agent to Castingwords. It provides structured and secure access so your agent can perform Castingwords operations on your behalf through a secure, permission-based interface.
With Composio's managed implementation, you don't have to create your own developer app. For production, if you're building an end product, we recommend using your own credentials. The managed server helps you prototype fast and go from 0-1 faster.

## Step-by-step Guide

### 1. Prerequisites

No description provided.

### 1. Getting API Keys for OpenAI and Composio

OpenAI API Key
- Go to the [OpenAI dashboard](https://platform.openai.com/settings/organization/api-keys) 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](https://dashboard.composio.dev?utm_source=toolkits&utm_medium=framework_docs).
- Navigate to your API settings and generate a new API key.
- Store this key securely as you'll need it for authentication.

### 2. Install dependencies

No description provided.
```python
pip install composio-langchain langchain-mcp-adapters langchain python-dotenv
```

```typescript
npm install @composio/langchain @langchain/core @langchain/openai @langchain/mcp-adapters dotenv
```

### 3. Set up environment variables

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
```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
```

### 4. Import dependencies

No description provided.
```python
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()
```

```typescript
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();
```

### 5. Initialize Composio client

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 Castingwords tools
- Validating that COMPOSIO_USER_ID is also set before proceeding
```python
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")
```

```typescript
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()
    });
```

### 6. Create a Tool Router session

What's happening:
- We're creating a Tool Router session that gives your agent access to Castingwords 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 Castingwords tools as needed
```python
# Create Tool Router session for Castingwords
session = composio.create(
    user_id=os.getenv("COMPOSIO_USER_ID"),
    toolkits=['castingwords']
)

url = session.mcp.url
```

```typescript
const session = await composio.create(
    userId as string,
    {
        toolkits: ['castingwords']
    }
);

const url = session.mcp.url;
```

### 7. Configure the agent with the MCP URL

No description provided.
```python
client = MultiServerMCPClient({
    "castingwords-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)
```

```typescript
const client = new MultiServerMCPClient({
    "castingwords-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 });
```

### 8. Set up interactive chat interface

No description provided.
```python
conversation_history = []

print("Chat started! Type 'exit' or 'quit' to end the conversation.\n")
print("Ask any Castingwords 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")
```

```typescript
let conversationHistory: any[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log("Ask any Castingwords 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);
    });
```

### 9. Run the application

No description provided.
```python
if __name__ == "__main__":
    asyncio.run(main())
```

```typescript
main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});
```

## Complete Code

```python
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=['castingwords']
    )

    url = session.mcp.url
    
    client = MultiServerMCPClient({
        "castingwords-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 Castingwords 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())
```

```typescript
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: ['castingwords']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "castingwords-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 Castingwords 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 Castingwords 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 Castingwords MCP Agent with another framework

- [OpenAI Agents SDK](https://composio.dev/toolkits/castingwords/framework/open-ai-agents-sdk)
- [Claude Agent SDK](https://composio.dev/toolkits/castingwords/framework/claude-agents-sdk)
- [Claude Code](https://composio.dev/toolkits/castingwords/framework/claude-code)
- [Claude Cowork](https://composio.dev/toolkits/castingwords/framework/claude-cowork)
- [Codex](https://composio.dev/toolkits/castingwords/framework/codex)
- [OpenClaw](https://composio.dev/toolkits/castingwords/framework/openclaw)
- [Hermes](https://composio.dev/toolkits/castingwords/framework/hermes-agent)
- [CLI](https://composio.dev/toolkits/castingwords/framework/cli)
- [Google ADK](https://composio.dev/toolkits/castingwords/framework/google-adk)
- [Vercel AI SDK](https://composio.dev/toolkits/castingwords/framework/ai-sdk)
- [Mastra AI](https://composio.dev/toolkits/castingwords/framework/mastra-ai)
- [LlamaIndex](https://composio.dev/toolkits/castingwords/framework/llama-index)
- [CrewAI](https://composio.dev/toolkits/castingwords/framework/crew-ai)

## Related Toolkits

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- [Google Docs](https://composio.dev/toolkits/googledocs) - Google Docs is a cloud-based word processor that enables document creation and real-time collaboration. Its seamless sharing and version history make team editing and content management a breeze.
- [Google Super](https://composio.dev/toolkits/googlesuper) - Google Super is an all-in-one suite combining Gmail, Drive, Calendar, Sheets, Analytics, and more. It gives you a unified platform to manage your digital life, boosting productivity and organization.
- [Affinda](https://composio.dev/toolkits/affinda) - Affinda is an AI-powered document processing platform that automates data extraction from resumes, invoices, and more. It streamlines document-heavy workflows by turning files into structured, actionable data.
- [Agility cms](https://composio.dev/toolkits/agility_cms) - Agility CMS is a headless content management system for building and managing digital experiences across platforms. It lets teams update content quickly and deliver omnichannel experiences with ease.
- [Algodocs](https://composio.dev/toolkits/algodocs) - Algodocs is an AI-powered platform that automates data extraction from business documents. It delivers fast, secure, and accurate processing without templates or manual training.
- [Api2pdf](https://composio.dev/toolkits/api2pdf) - Api2Pdf is a REST API for generating PDFs from HTML, URLs, and documents using powerful engines like wkhtmltopdf and Headless Chrome. It streamlines document conversion and automation for developers and businesses.
- [Aryn](https://composio.dev/toolkits/aryn) - Aryn is an AI-powered platform for parsing, extracting, and analyzing data from unstructured documents. Use it to automate document processing and unlock actionable insights from your files.
- [Boldsign](https://composio.dev/toolkits/boldsign) - Boldsign is a digital eSignature platform for sending, signing, and tracking documents online. Organizations use it to automate agreements and manage legally binding workflows efficiently.
- [Boloforms](https://composio.dev/toolkits/boloforms) - BoloForms is an eSignature platform built for small businesses, offering unlimited signatures, templates, and forms. It simplifies digital document signing and team collaboration at a predictable, fixed price.
- [Box](https://composio.dev/toolkits/box) - Box is a cloud content management and file sharing platform for businesses. It helps teams securely store, organize, and collaborate on files from anywhere.
- [Carbone](https://composio.dev/toolkits/carbone) - Carbone is a blazing-fast report generator that turns JSON data into PDFs, Word docs, spreadsheets, and more using flexible templates. It lets you automate document creation at scale with minimal code.
- [Cloudconvert](https://composio.dev/toolkits/cloudconvert) - CloudConvert is a powerful file conversion service supporting over 200 file formats. It streamlines converting, compressing, and managing documents, media, and more, all in one place.
- [Cloudlayer](https://composio.dev/toolkits/cloudlayer) - Cloudlayer is a document and asset generation service for creating PDFs and images via API or SDKs. It lets you automate high-quality doc creation, saving dev time and reducing manual work.
- [Cloudpress](https://composio.dev/toolkits/cloudpress) - Cloudpress is a content export tool for Google Docs and Notion. It automates publishing to your favorite Content Management Systems.
- [Contentful graphql](https://composio.dev/toolkits/contentful_graphql) - Contentful graphql is a content delivery API that lets you access Contentful data using GraphQL queries. It gives you efficient, flexible ways to fetch and manage structured content for any digital project.
- [Conversion tools](https://composio.dev/toolkits/conversion_tools) - Conversion Tools is an online service for converting documents between formats such as PDF, Word, Excel, XML, and CSV. It lets you automate complex document workflows with just a few clicks.
- [Convertapi](https://composio.dev/toolkits/convertapi) - ConvertAPI is a robust file conversion service for documents, images, and spreadsheets. It streamlines programmatic format changes and lets developers automate complex workflows with a single API.
- [Craftmypdf](https://composio.dev/toolkits/craftmypdf) - CraftMyPDF is a web-based service for designing and generating PDFs with templates and live data. It streamlines document creation by automating personalized PDFs at scale.
- [Docmosis](https://composio.dev/toolkits/docmosis) - Docmosis generates PDF and Word documents from user-defined templates. It's perfect for merging data fields to quickly produce reports, invoices, and business letters.

## Frequently Asked Questions

### What are the differences in Tool Router MCP and Castingwords MCP?

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

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

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

---
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