diff --git a/backend/internal/server/middleware/api_key_auth_google.go b/backend/internal/server/middleware/api_key_auth_google.go
index e37b389e..199aca82 100644
--- a/backend/internal/server/middleware/api_key_auth_google.go
+++ b/backend/internal/server/middleware/api_key_auth_google.go
@@ -8,7 +8,6 @@ import (
 	"github.com/Wei-Shaw/sub2api/internal/service"
 
 	"github.com/gin-gonic/gin"
-	"gorm.io/gorm"
 )
 
 // ApiKeyAuthGoogle is a Google-style error wrapper for API key auth.
@@ -30,7 +29,7 @@ func ApiKeyAuthWithSubscriptionGoogle(apiKeyService *service.ApiKeyService, subs
 
 		apiKey, err := apiKeyService.GetByKey(c.Request.Context(), apiKeyString)
 		if err != nil {
-			if errors.Is(err, gorm.ErrRecordNotFound) {
+			if errors.Is(err, service.ErrApiKeyNotFound) {
 				abortWithGoogleError(c, 401, "Invalid API key")
 				return
 			}
diff --git a/frontend/src/api/usage.ts b/frontend/src/api/usage.ts
index f0aec5fb..6efd7657 100644
--- a/frontend/src/api/usage.ts
+++ b/frontend/src/api/usage.ts
@@ -152,8 +152,8 @@ export async function getStatsByDateRange(
 
 /**
  * Get usage by date range
- * @param startDate - Start date (ISO format)
- * @param endDate - End date (ISO format)
+ * @param startDate - Start date (YYYY-MM-DD format)
+ * @param endDate - End date (YYYY-MM-DD format)
  * @param apiKeyId - Optional API key ID filter
  * @returns Usage logs within date range
  */