chore: import upstream snapshot with attribution

gateway/mcp/example_test.go

@@ -0,0 +1,135 @@
+package mcp
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+
+	"go-micro.dev/v6"
+	"go-micro.dev/v6/auth/jwt"
+	"go-micro.dev/v6/registry"
+)
+
+// Example_withMCP shows the simplest way to add MCP to a service using WithMCP
+func Example_withMCP() {
+	// One line to make your service AI-accessible
+	service := micro.NewService("myservice", WithMCP(":3000"))
+	service.Init()
+	service.Run()
+}
+
+// Example_inlineGateway shows how to add MCP gateway to an existing service
+// with full control over options
+func Example_inlineGateway() {
+	service := micro.NewService("myservice")
+	service.Init()
+
+	// Add MCP gateway alongside your service
+	go func() {
+		if err := Serve(Options{
+			Registry: service.Options().Registry,
+			Address:  ":3000",
+		}); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	// Run your service normally
+	service.Run()
+}
+
+// Example_standaloneGateway shows how to run MCP gateway as a separate service
+func Example_standaloneGateway() {
+	// Standalone MCP gateway
+	// Discovers all services via registry
+	if err := ListenAndServe(":3000", Options{
+		Registry: registry.NewMDNSRegistry(),
+	}); err != nil {
+		log.Fatal(err)
+	}
+}
+
+// Example_withAuthentication shows how to add authentication
+func Example_withAuthentication() {
+	service := micro.NewService("myservice")
+	service.Init()
+
+	go func() {
+		if err := Serve(Options{
+			Registry: service.Options().Registry,
+			Address:  ":3000",
+			AuthFunc: func(r *http.Request) error {
+				token := r.Header.Get("Authorization")
+				if token == "" {
+					return fmt.Errorf("missing authorization header")
+				}
+				// Validate token here
+				return nil
+			},
+		}); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	service.Run()
+}
+
+// Example_customContext shows how to use a custom context for graceful shutdown
+func Example_customContext() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	service := micro.NewService("myservice")
+	service.Init()
+
+	go func() {
+		if err := Serve(Options{
+			Registry: service.Options().Registry,
+			Address:  ":3000",
+			Context:  ctx,
+		}); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	service.Run()
+	// cancel() will stop the MCP gateway
+}
+
+// Example_withScopesAndTracing shows how to add per-tool scopes, tracing, rate
+// limiting and audit logging to the MCP gateway. Services register scope
+// requirements via endpoint metadata ("scopes" key, comma-separated).
+func Example_withScopesAndTracing() {
+	service := micro.NewService("blog")
+	service.Init()
+
+	// Use JWT auth provider
+	authProvider := jwt.NewAuth()
+
+	go func() {
+		if err := Serve(Options{
+			Registry: service.Options().Registry,
+			Address:  ":3000",
+
+			// Auth inspects Bearer tokens and enforces per-tool scopes
+			Auth: authProvider,
+
+			// Rate limit all tools to 10 req/s with burst of 20
+			RateLimit: &RateLimitConfig{
+				RequestsPerSecond: 10,
+				Burst:             20,
+			},
+
+			// Audit every tool call for compliance
+			AuditFunc: func(r AuditRecord) {
+				log.Printf("[audit] trace=%s tool=%s account=%s allowed=%v reason=%s",
+					r.TraceID, r.Tool, r.AccountID, r.Allowed, r.DeniedReason)
+			},
+		}); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	service.Run()
+}