net/http

This page details the examples found in the /examples/http directory, demonstrating how to set up an MCP server using the HTTP + Server-Sent Events (SSE) hybrid transport.

This transport uses:

• HTTP POST: For client-to-server messages (requests like tools/call, notifications like initialized).
• Server-Sent Events (SSE): For server-to-client messages (responses like initialize result, notifications like $/progress, server-sent requests).

The transport/sse package provides an sse.Server that handles the transport logic. You typically integrate its handlers into your chosen Go web framework or the standard net/http library.

Standard Library (net/http) Example (examples/http/nethttp)

This example shows how to integrate the sse.Server with Go’s built-in net/http package.

Key parts:

package main

import (
	"log"
	"net/http"
	// ... other imports: server, protocol, types ...
	"github.com/localrivet/gomcp/transport/sse"
)

func main() {
	// 1. Setup MCP Server (like in basic examples)
	serverInfo := types.Implementation{Name: "http-server", Version: "0.1.0"}
	opts := server.NewServerOptions(serverInfo)
	// opts.Capabilities... // Set capabilities
	srv := server.NewServer(opts)
	// srv.RegisterTool(...) // Register tools, resources, etc.

	// 2. Create SSE Transport Server
	sseServer := sse.NewServer(srv, opts.Logger) // Pass the MCP server instance

	// 3. Setup HTTP Handlers
	mux := http.NewServeMux()
	// The SSE handler manages the persistent event stream
	mux.HandleFunc("/events", sseServer.HTTPHandler)
	// The Message handler receives client POST requests
	mux.HandleFunc("/message", srv.HTTPHandler) // Use the MCP server's handler

	// 4. Start HTTP Server
	log.Println("Starting HTTP+SSE MCP server on :8080...")
	if err := http.ListenAndServe(":8080", mux); err != nil {
		log.Fatalf("HTTP server error: %v", err)
	}
}

To Run: Navigate to examples/http/nethttp and run go run main.go. Clients can then connect by establishing an SSE connection to /events and sending POST requests to /message.

Other Frameworks

The /examples/http directory contains similar integrations for popular frameworks like Gin, Echo, Chi, Fiber, etc. The core principle remains the same:

1. Initialize the server.Server.
2. Initialize the sse.Server, passing the server.Server instance.
3. Mount the sseServer.HTTPHandler to an endpoint for the event stream (e.g., /events).
4. Mount the srv.HTTPHandler to an endpoint for receiving client messages (e.g., /message).

Refer to the specific subdirectories for framework-specific integration details.