examples/

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/render",
  "params": { "name": "greeting", "args": { "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