MCP Tools Overview

MCP (Model Context Protocol) tools allow AI assistants like ChatGPT to interact with your application's data and functionality. These tools act as bridges between AI models and your backend systems.

What are MCP Tools?

MCP tools are functions that AI models can call to:

• Query data from your database (users, organizations, payments)
• Execute operations (send emails, update records, trigger workflows)
• Access real-time information that isn't in the model's training data
• Perform actions on behalf of authenticated users

How MCP Works

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   ChatGPT   │────▶│  MCP Server │────▶│  Your API   │
│   Client    │◄────│  (Route)    │◄────│  (Tools)    │
└─────────────┘     └─────────────┘     └─────────────┘

1. User asks ChatGPT a question that requires data from your app
2. ChatGPT decides which MCP tool to call based on the tool's description
3. MCP Server receives the request and validates authentication
4. Your Tool executes the logic and returns data
5. ChatGPT formats the response for the user

Built-in Admin Tools

The starter kit includes a set of admin tools available at /api/adminx/mcp:

Tool Structure

Each MCP tool follows a consistent pattern:

server.tool(
  "tool_name",           // Unique identifier
  "Tool description",    // Description for the AI model
  {                      // Zod schema for parameters
    param1: z.string(),
    param2: z.number().optional(),
  },
  async ({ param1, param2 }) => {
    // Tool implementation
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(result, null, 2),
        },
      ],
    };
  },
);

Authentication

MCP tools can be protected using your existing auth system:

import { auth } from "@repo/auth/server";
import { headers } from "next/headers";

async function requireAuth() {
  const session = await auth.api.getSession({
    headers: await headers(),
  });

  if (!session?.user?.id) {
    throw new Error("Unauthorized");
  }

  return session;
}

Next Steps

• Registering Custom Tools - Learn how to add your own MCP tools
• ChatGPT SDK Overview - Overview of the ChatGPT SDK integration