MCP (Model Context Protocol) Server

Let's experiment with creating our own MCP server to learn how this technology works in depth.

Here is a settled GitHub Copilot Space for this repository: https://github.com/copilot/spaces/linnienaryshkin/1

Goal

I want to build an MCP server that can be connected from MCP clients such as Cursor or VS Code GitHub Copilot, then send a message to my MS Teams chat through Agent mode.

Theory | The basics

MCP is a protocol for communication between AI agents and tools. It defines a standard way for agents to interact with tools, and for tools to provide information back to agents. MCP is designed to be flexible and extensible, allowing for a wide range of use cases.

Key Terminology

MCP Client: An application that implements the MCP protocol to communicate with an MCP server. Examples include Cursor, VS Code GitHub Copilot, Cloud Desktop, and more.
- Contains or orchestrates access to the model
- Sends prompts to the LLM
- Sends tool requests to the MCP server
LLM (Large Language Model): The model that processes prompts and generates responses.
MCP Server: The server that implements the MCP protocol to handle requests from MCP clients and interact with tools.
- Hosts and executes tools
- Hosts resources
- Hosts reusable prompts
- Validates input

Tools, Resources, Prompts

Tools: Functions or APIs that the MCP server can execute on behalf of the MCP client. Tools can perform various tasks, such as fetching data, performing calculations, or interacting with external services.
- Name
- Description
- Input schema
- Output schema
Resources: Data or information that the MCP server can provide to the MCP client.
Prompts: Predefined prompts that the MCP server can provide to the MCP client.

Communication | JSON-RPC

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "send_message_to_teams",
    "arguments": {
      "message": "Hello, MS Teams!"
    }
  },
  "id": 1
}

Transport Layer (HTTP, SSE, Streamable HTTP)

Standard HTTP

Request-response model
Best for quick and simple interactions
Limited by latency and connection overhead

Server-Sent Events (SSE)

Unidirectional communication from server to client
Best for real-time updates and notifications

Streamable HTTP

Allows continuous data streaming between client and server
Best for long-running tasks and large data transfers
Currently considered to be the future of MCP communication

Setup

Install dependencies from the root of the repository:

npm install

Teams MCP Server