diff --git a/backend/internal/pkg/antigravity/oauth.go b/backend/internal/pkg/antigravity/oauth.go
index ee2a6c1a..c7d657b9 100644
--- a/backend/internal/pkg/antigravity/oauth.go
+++ b/backend/internal/pkg/antigravity/oauth.go
@@ -33,7 +33,7 @@ const (
 		"https://www.googleapis.com/auth/experimentsandconfigs"
 
 	// User-Agent（与 Antigravity-Manager 保持一致）
-	UserAgent = "antigravity/1.11.9 windows/amd64"
+	UserAgent = "antigravity/1.15.8 windows/amd64"
 
 	// Session 过期时间
 	SessionTTL = 30 * time.Minute