yasel-scf/assistender-mcp-server

Assistender MCP Server

A scaffold project for deploying a Model Context Protocol (MCP) server compatible with the OpenAI Apps SDK. This server provides a basic implementation using the official @modelcontextprotocol/sdk library with TypeScript and Node.js.

Overview

The Model Context Protocol (MCP) is an open specification for connecting large language model clients to external tools, data, and user interfaces. This scaffold provides a minimal MCP server that:

1. Lists tools – Advertises available tools with their JSON Schema contracts
2. Calls tools – Executes tool requests from the model
3. Returns structured content – Sends back formatted responses

Prerequisites

• Node.js 18+
• npm, yarn, or pnpm for dependency management

Installation

Clone the repository and install dependencies:

npm install

Or using pnpm:

pnpm install

Usage

Start the MCP server:

npm start

The server will start on port 8000 (or the port specified in the PORT environment variable) and expose:

• SSE stream: GET http://localhost:8000/mcp
• Message endpoint: POST http://localhost:8000/mcp/messages?sessionId=...

Project Structure

assistender-mcp-server/
├── src/
│   └── server.ts          # Main MCP server implementation
├── package.json           # Dependencies and scripts
├── tsconfig.json          # TypeScript configuration
├── .gitignore             # Git ignore rules
└── README.md              # This file

Adding Custom Tools

To add your own tools, modify src/server.ts:

1. Define your tool schema in the tools array
2. Add a handler in the CallToolRequestSchema request handler
3. Return structured content that matches your tool's output schema

Example:

const tools: Tool[] = [
  {
    name: "my-custom-tool",
    description: "Description of what this tool does",
    inputSchema: {
      type: "object",
      properties: {
        param1: {
          type: "string",
          description: "Parameter description",
        },
      },
      required: ["param1"],
    },
  },
];

OpenAI Apps SDK Integration

This MCP server follows the OpenAI Apps SDK specifications and can be integrated with ChatGPT developer mode. The server uses Server-Sent Events (SSE) transport, making it compatible with MCP inspectors and ChatGPT connectors.

For more information, see:

• OpenAI Apps SDK Documentation
• OpenAI Apps SDK Examples
• Model Context Protocol

Development

The project uses:

• TypeScript for type safety
• tsx for running TypeScript directly
• Zod for runtime schema validation
• @modelcontextprotocol/sdk for MCP implementation

License

MIT