examples/

README

GoMCP Examples

This directory contains examples for using the GoMCP library.

Server Example

The server example demonstrates how to create and run an MCP server with stdio transport.

Features Demonstrated

• Creating a server with server.NewServer()
• Configuring file-based logging with slog.DefaultConfig() and slog.NewLoggerWithConfig()
• Registering tools, resources, and prompts
• Setting root paths for filesystem access
• Using stdio transport with srv.AsStdio()

Running the Server

# Build the server example
go build -o examples/server/server examples/server/main.go

# Run the server
./examples/server/server

The server will:

• Log messages to the logs directory (created automatically)
• Use text format for better human readability
• Print a brief message to the console to confirm startup

The server exposes:

• A tool called "echo" that echoes back a message
• A resource at "/hello" that returns a simple greeting
• A prompt called "greeting" that formats a greeting with a name
• Root paths set to the examples and server directories

Testing with JSON-RPC Messages

Since this is a stdio-based server, you can interact with it by sending JSON-RPC messages to its standard input. Here are some example messages you can paste into the terminal:

Initialize

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": { "protocolVersion": "draft" }
}

Call the Echo Tool

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": { "name": "echo", "args": { "message": "Hello from JSON-RPC!" } }
}

Get the Hello Resource

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "resources/read",
  "params": { "uri": "/hello" }
}

Render the Greeting Prompt

{
  "jsonrpc": "2.0",
  "id": 4,
  "method": "prompts/get",
  "params": { "name": "greeting", "arguments": { "name": "Example User" } }
}

List Tools

{ "jsonrpc": "2.0", "id": 5, "method": "tools/list" }

Copy and paste these messages one at a time into the terminal where the server is running. The server will process each message and return a JSON-RPC response.

Viewing Logs

The logs will be in the logs directory with filenames like:

mcp-example-2023-08-10-15-30-45.log

You can view the logs with any text editor or using commands like:

cat logs/mcp-example-*.log