diff --git a/client/transport/stdio_test.go b/client/transport/stdio_test.go
index 445ba07ea..e6cdb30db 100644
--- a/client/transport/stdio_test.go
+++ b/client/transport/stdio_test.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"sync"
 	"testing"
 	"time"
@@ -31,6 +32,10 @@ func compileTestServer(outputPath string) error {
 func TestStdio(t *testing.T) {
 	// Compile mock server
 	mockServerPath := filepath.Join(os.TempDir(), "mockstdio_server")
+		// Add .exe suffix on Windows
+		if runtime.GOOS == "windows" {
+			mockServerPath += ".exe"
+		}
 	if err := compileTestServer(mockServerPath); err != nil {
 		t.Fatalf("Failed to compile mock server: %v", err)
 	}
@@ -302,8 +307,11 @@ func TestStdioErrors(t *testing.T) {
 	})
 
 	t.Run("RequestBeforeStart", func(t *testing.T) {
-		// 创建一个新的 Stdio 实例但不调用 Start 方法
 		mockServerPath := filepath.Join(os.TempDir(), "mockstdio_server")
+		// Add .exe suffix on Windows
+		if runtime.GOOS == "windows" {
+			mockServerPath += ".exe"
+		}
 		if err := compileTestServer(mockServerPath); err != nil {
 			t.Fatalf("Failed to compile mock server: %v", err)
 		}
@@ -311,7 +319,7 @@ func TestStdioErrors(t *testing.T) {
 
 		uninitiatedStdio := NewStdio(mockServerPath, nil)
 
-		// 准备一个请求
+		// Prepare a request
 		request := JSONRPCRequest{
 			JSONRPC: "2.0",
 			ID:      99,
@@ -331,6 +339,10 @@ func TestStdioErrors(t *testing.T) {
 	t.Run("RequestAfterClose", func(t *testing.T) {
 		// Compile mock server
 		mockServerPath := filepath.Join(os.TempDir(), "mockstdio_server")
+		// Add .exe suffix on Windows
+		if runtime.GOOS == "windows" {
+			mockServerPath += ".exe"
+		}
 		if err := compileTestServer(mockServerPath); err != nil {
 			t.Fatalf("Failed to compile mock server: %v", err)
 		}
diff --git a/server/sse.go b/server/sse.go
index f69451c6d..5dc9adaf1 100644
--- a/server/sse.go
+++ b/server/sse.go
@@ -65,6 +65,8 @@ type SSEServer struct {
 
 	keepAlive         bool
 	keepAliveInterval time.Duration
+	
+	mu               sync.RWMutex
 }
 
 // SSEOption defines a function type for configuring SSEServer
@@ -189,10 +191,12 @@ func NewTestServer(server *MCPServer, opts ...SSEOption) *httptest.Server {
 // Start begins serving SSE connections on the specified address.
 // It sets up HTTP handlers for SSE and message endpoints.
 func (s *SSEServer) Start(addr string) error {
+	s.mu.Lock()
 	s.srv = &http.Server{
 		Addr:    addr,
 		Handler: s,
 	}
+	s.mu.Unlock()
 
 	return s.srv.ListenAndServe()
 }
@@ -200,7 +204,11 @@ func (s *SSEServer) Start(addr string) error {
 // Shutdown gracefully stops the SSE server, closing all active sessions
 // and shutting down the HTTP server.
 func (s *SSEServer) Shutdown(ctx context.Context) error {
-	if s.srv != nil {
+	s.mu.RLock()
+	srv := s.srv
+	s.mu.RUnlock()
+
+	if srv != nil {
 		s.sessions.Range(func(key, value interface{}) bool {
 			if session, ok := value.(*sseSession); ok {
 				close(session.done)
@@ -209,7 +217,7 @@ func (s *SSEServer) Shutdown(ctx context.Context) error {
 			return true
 		})
 
-		return s.srv.Shutdown(ctx)
+		return srv.Shutdown(ctx)
 	}
 	return nil
 }
@@ -335,7 +343,6 @@ func (s *SSEServer) handleMessage(w http.ResponseWriter, r *http.Request) {
 		s.writeJSONRPCError(w, nil, mcp.INVALID_PARAMS, "Missing sessionId")
 		return
 	}
-
 	sessionI, ok := s.sessions.Load(sessionID)
 	if !ok {
 		s.writeJSONRPCError(w, nil, mcp.INVALID_PARAMS, "Invalid session ID")