diff --git a/agent/assistant/sandbox_integration_test.go b/agent/assistant/sandbox_integration_test.go
index d9276b57..024c5869 100644
--- a/agent/assistant/sandbox_integration_test.go
+++ b/agent/assistant/sandbox_integration_test.go
@@ -181,8 +181,8 @@ func TestHasSandboxMethod(t *testing.T) {
 	require.NoError(t, err)
 	assert.True(t, astWithSandbox.HasSandbox(), "Assistant with sandbox config should return true")
 
-	// Test assistant without sandbox (fullfields doesn't have sandbox)
-	astWithoutSandbox, err := assistant.LoadPath("/assistants/tests/fullfields")
+	// Test assistant without sandbox
+	astWithoutSandbox, err := assistant.LoadPath("/assistants/tests/simple-greeting")
 	require.NoError(t, err)
 	assert.False(t, astWithoutSandbox.HasSandbox(), "Assistant without sandbox config should return false")
 }
diff --git a/agent/store/xun/xun.go b/agent/store/xun/xun.go
index dc3d8559..e04a4131 100644
--- a/agent/store/xun/xun.go
+++ b/agent/store/xun/xun.go
@@ -168,9 +168,18 @@ func (store *Xun) getAssistantTable() string {
 func (store *Xun) parseJSONFields(data map[string]interface{}, fields []string) {
 	for _, field := range fields {
 		if val := data[field]; val != nil {
-			if strVal, ok := val.(string); ok && strVal != "" {
+			var jsonStr string
+			switch v := val.(type) {
+			case string:
+				jsonStr = v
+			case []byte:
+				jsonStr = string(v)
+			default:
+				continue
+			}
+			if jsonStr != "" {
 				var parsed interface{}
-				if err := jsoniter.UnmarshalFromString(strVal, &parsed); err == nil {
+				if err := jsoniter.UnmarshalFromString(jsonStr, &parsed); err == nil {
 					data[field] = parsed
 				}
 			}