diff --git a/service/service.go b/service/service.go
index e45b088..9d0456f 100644
--- a/service/service.go
+++ b/service/service.go
@@ -108,7 +108,13 @@ func Router(cfg *Config) *gin.Engine {
 	// Free API endpoint, No Pro Account required
 	r.POST("/translate", authMiddleware(cfg), func(c *gin.Context) {
 		req := PayloadFree{}
-		c.BindJSON(&req)
+		if err := c.BindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"code":    http.StatusBadRequest,
+				"message": "Invalid request payload",
+			})
+			return
+		}
 
 		sourceLang := req.SourceLang
 		targetLang := req.TargetLang
@@ -156,7 +162,13 @@ func Router(cfg *Config) *gin.Engine {
 	// Pro API endpoint, Pro Account required
 	r.POST("/v1/translate", authMiddleware(cfg), func(c *gin.Context) {
 		req := PayloadFree{}
-		c.BindJSON(&req)
+		if err := c.BindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"code":    http.StatusBadRequest,
+				"message": "Invalid request payload",
+			})
+			return
+		}
 
 		sourceLang := req.SourceLang
 		targetLang := req.TargetLang