# How to integrate Castingwords MCP with Vercel AI SDK v6

```json
{
  "title": "How to integrate Castingwords MCP with Vercel AI SDK v6",
  "toolkit": "Castingwords",
  "toolkit_slug": "castingwords",
  "framework": "Vercel AI SDK",
  "framework_slug": "ai-sdk",
  "url": "https://composio.dev/toolkits/castingwords/framework/ai-sdk",
  "markdown_url": "https://composio.dev/toolkits/castingwords/framework/ai-sdk.md",
  "updated_at": "2026-05-12T10:05:47.733Z"
}
```

## Introduction

This guide walks you through connecting Castingwords to Vercel AI SDK v6 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 Vercel AI SDK 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)
- [LangChain](https://composio.dev/toolkits/castingwords/framework/langchain)
- [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:
- How to set up and configure a Vercel AI SDK agent with Castingwords integration
- Using Composio's Tool Router to dynamically load and access Castingwords tools
- Creating an MCP client connection using HTTP transport
- Building an interactive CLI chat interface with conversation history management
- Handling tool calls and results within the Vercel AI SDK framework

## What is Vercel AI SDK?

The Vercel AI SDK is a TypeScript library for building AI-powered applications. It provides tools for creating agents that can use external services and maintain conversation state.
Key features include:
- streamText: Core function for streaming responses with real-time tool support
- MCP Client: Built-in support for Model Context Protocol via @ai-sdk/mcp
- Step Counting: Control multi-step tool execution with stopWhen: stepCountIs()
- OpenAI Provider: Native integration with OpenAI models

## 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

Before you begin, make sure you have:
- Node.js and npm installed
- A Composio account with API key
- An OpenAI API key

### 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 required dependencies

First, install the necessary packages for your project.
What you're installing:
- @ai-sdk/openai: Vercel AI SDK's OpenAI provider
- @ai-sdk/mcp: MCP client for Vercel AI SDK
- @composio/core: Composio SDK for tool integration
- ai: Core Vercel AI SDK
- dotenv: Environment variable management
```bash
npm install @ai-sdk/openai @ai-sdk/mcp @composio/core ai dotenv
```

### 3. Set up environment variables

Create a .env file in your project root.
What's needed:
- OPENAI_API_KEY: Your OpenAI API key for GPT model access
- COMPOSIO_API_KEY: Your Composio API key for tool access
- COMPOSIO_USER_ID: A unique identifier for the user session
```bash
OPENAI_API_KEY=your_openai_api_key_here
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_user_id_here
```

### 4. Import required modules and validate environment

What's happening:
- We're importing all necessary libraries including Vercel AI SDK's OpenAI provider and Composio
- The dotenv/config import automatically loads environment variables
- The MCP client import enables connection to Composio's tool server
```typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Composio } from "@composio/core";
import * as readline from "readline";
import { streamText, type ModelMessage, stepCountIs } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!process.env.OPENAI_API_KEY) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({
  apiKey: composioAPIKey,
});
```

### 5. Create Tool Router session and initialize MCP client

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 mcp object contains the URL and authentication headers needed to connect to the MCP server
- This session provides access to all Castingwords-related tools through the MCP protocol
```typescript
async function main() {
  // Create a tool router session for the user
  const session = await composio.create(composioUserID!, {
    toolkits: ["castingwords"],
  });

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

### 6. Connect to MCP server and retrieve tools

What's happening:
- We're creating an MCP client that connects to our Composio Tool Router session via HTTP
- The mcp.url provides the endpoint, and mcp.headers contains authentication credentials
- The type: "http" is important - Composio requires HTTP transport
- tools() retrieves all available Castingwords tools that the agent can use
```typescript
const mcpClient = await createMCPClient({
  transport: {
    type: "http",
    url: mcpUrl,
    headers: session.mcp.headers, // Authentication headers for the Composio MCP server
  },
});

const tools = await mcpClient.tools();
```

### 7. Initialize conversation and CLI interface

What's happening:
- We initialize an empty messages array to maintain conversation history
- A readline interface is created to accept user input from the command line
- Instructions are displayed to guide the user on how to interact with the agent
```typescript
let messages: ModelMessage[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log(
  "Ask any questions related to castingwords, like summarize my last 5 emails, send an email, etc... :)))\n",
);

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  prompt: "> ",
});

rl.prompt();
```

### 8. Handle user input and stream responses with real-time tool feedback

What's happening:
- We use streamText instead of generateText to stream responses in real-time
- toolChoice: "auto" allows the model to decide when to use Castingwords tools
- stopWhen: stepCountIs(10) allows up to 10 steps for complex multi-tool operations
- onStepFinish callback displays which tools are being used in real-time
- We iterate through the text stream to create a typewriter effect as the agent responds
- The complete response is added to conversation history to maintain context
- Errors are caught and displayed with helpful retry suggestions
```typescript
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;
  }

  messages.push({ role: "user", content: trimmedInput });
  console.log("\nAgent is thinking...\n");

  try {
    const stream = streamText({
      model: openai("gpt-5"),
      messages,
      tools,
      toolChoice: "auto",
      stopWhen: stepCountIs(10),
      onStepFinish: (step) => {
        for (const toolCall of step.toolCalls) {
          console.log(`[Using tool: ${toolCall.toolName}]`);
          }
          if (step.toolCalls.length > 0) {
            console.log(""); // Add space after tool calls
          }
        },
      });

      for await (const chunk of stream.textStream) {
        process.stdout.write(chunk);
      }

      console.log("\n\n---\n");

      // Get final result for message history
      const response = await stream.response;
      if (response?.messages?.length) {
        messages.push(...response.messages);
      }
    } catch (error) {
      console.error("\nAn error occurred while talking to the agent:");
      console.error(error);
      console.log(
        "\nYou can try again or restart the app if it keeps happening.\n",
      );
    } finally {
      rl.prompt();
    }
  });

  rl.on("close", async () => {
    await mcpClient.close();
    console.log("\n👋 Session ended.");
    process.exit(0);
  });
}

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

## Complete Code

```typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Composio } from "@composio/core";
import * as readline from "readline";
import { streamText, type ModelMessage, stepCountIs } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!process.env.OPENAI_API_KEY) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({
  apiKey: composioAPIKey,
});

async function main() {
  // Create a tool router session for the user
  const session = await composio.create(composioUserID!, {
    toolkits: ["castingwords"],
  });

  const mcpUrl = session.mcp.url;

  const mcpClient = await createMCPClient({
    transport: {
      type: "http",
      url: mcpUrl,
      headers: session.mcp.headers, // Authentication headers for the Composio MCP server
    },
  });

  const tools = await mcpClient.tools();

  let messages: ModelMessage[] = [];

  console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
  console.log(
    "Ask any questions related to castingwords, like summarize my last 5 emails, send an email, etc... :)))\n",
  );

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: "> ",
  });

  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;
    }

    messages.push({ role: "user", content: trimmedInput });
    console.log("\nAgent is thinking...\n");

    try {
      const stream = streamText({
        model: openai("gpt-5"),
        messages,
        tools,
        toolChoice: "auto",
        stopWhen: stepCountIs(10),
        onStepFinish: (step) => {
          for (const toolCall of step.toolCalls) {
            console.log(`[Using tool: ${toolCall.toolName}]`);
          }
          if (step.toolCalls.length > 0) {
            console.log(""); // Add space after tool calls
          }
        },
      });

      for await (const chunk of stream.textStream) {
        process.stdout.write(chunk);
      }

      console.log("\n\n---\n");

      // Get final result for message history
      const response = await stream.response;
      if (response?.messages?.length) {
        messages.push(...response.messages);
      }
    } catch (error) {
      console.error("\nAn error occurred while talking to the agent:");
      console.error(error);
      console.log(
        "\nYou can try again or restart the app if it keeps happening.\n",
      );
    } finally {
      rl.prompt();
    }
  });

  rl.on("close", async () => {
    await mcpClient.close();
    console.log("\n👋 Session ended.");
    process.exit(0);
  });
}

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

## Conclusion

You've successfully built a Castingwords agent using the Vercel AI SDK with streaming capabilities! This implementation provides a powerful foundation for building AI applications with natural language interfaces and real-time feedback.
Key features of this implementation:
- Real-time streaming responses for a better user experience with typewriter effect
- Live tool execution feedback showing which tools are being used as the agent works
- Dynamic tool loading through Composio's Tool Router with secure authentication
- Multi-step tool execution with configurable step limits (up to 10 steps)
- Comprehensive error handling for robust agent execution
- Conversation history maintenance for context-aware responses
You can extend this further by adding custom 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)
- [LangChain](https://composio.dev/toolkits/castingwords/framework/langchain)
- [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

- [Google Drive](https://composio.dev/toolkits/googledrive) - Google Drive is a cloud storage platform for uploading, sharing, and collaborating on files. It's perfect for keeping your documents accessible and organized across devices.
- [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 Vercel AI SDK v6?

Yes, you can. Vercel AI SDK v6 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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