diff --git a/engine/core/session.py b/engine/core/session.py
index 4f19eba..1cfaeac 100644
--- a/engine/core/session.py
+++ b/engine/core/session.py
@@ -71,6 +71,32 @@ class Session:
         "configVersionId",
         "config_version_id",
     }
+    _CLIENT_SERVICE_OVERRIDES = {
+        "llm": {
+            "provider",
+            "model",
+            "apiKey",
+            "baseUrl",
+        },
+        "asr": {
+            "provider",
+            "model",
+            "apiKey",
+            "baseUrl",
+            "interimIntervalMs",
+            "minAudioMs",
+        },
+        "tts": {
+            "enabled",
+            "provider",
+            "model",
+            "apiKey",
+            "baseUrl",
+            "voice",
+            "speed",
+            "mode",
+        },
+    }
 
     def __init__(
         self,
@@ -853,13 +879,52 @@ class Session:
     def _sanitize_client_metadata(self, metadata: Dict[str, Any]) -> Dict[str, Any]:
         """Apply client metadata whitelist and remove forbidden secrets."""
         sanitized = self._sanitize_untrusted_runtime_metadata(metadata)
-        if isinstance(metadata.get("services"), dict):
-            logger.warning(
-                "Session {} provided metadata.services from client; client-side service config is ignored",
-                self.id,
-            )
+        services = metadata.get("services")
+        if isinstance(services, dict):
+            if self._is_debug_metadata_source(metadata):
+                sanitized_services = self._sanitize_client_services(services)
+                if sanitized_services:
+                    sanitized["services"] = sanitized_services
+            else:
+                logger.warning(
+                    "Session {} provided metadata.services from client; client-side service config is ignored",
+                    self.id,
+                )
         return sanitized
 
+    @staticmethod
+    def _is_debug_metadata_source(metadata: Dict[str, Any]) -> bool:
+        source = str(metadata.get("source") or "").strip().lower()
+        if source == "debug":
+            return True
+
+        history = metadata.get("history")
+        if isinstance(history, dict):
+            history_source = str(history.get("source") or "").strip().lower()
+            if history_source == "debug":
+                return True
+        return False
+
+    @classmethod
+    def _sanitize_client_services(cls, services: Dict[str, Any]) -> Dict[str, Any]:
+        if not isinstance(services, dict):
+            return {}
+
+        sanitized_services: Dict[str, Any] = {}
+        for service_name, allowed_keys in cls._CLIENT_SERVICE_OVERRIDES.items():
+            payload = services.get(service_name)
+            if not isinstance(payload, dict):
+                continue
+
+            sanitized_payload = {
+                key: payload[key]
+                for key in allowed_keys
+                if key in payload
+            }
+            if sanitized_payload:
+                sanitized_services[service_name] = sanitized_payload
+        return sanitized_services
+
     def _build_config_resolved(self, metadata: Dict[str, Any]) -> Dict[str, Any]:
         """Build public resolved config payload (secrets removed)."""
         system_prompt = str(metadata.get("systemPrompt") or self.pipeline.conversation.system_prompt or "")
diff --git a/web/pages/Assistants.tsx b/web/pages/Assistants.tsx
index 1da3915..0aaf909 100644
--- a/web/pages/Assistants.tsx
+++ b/web/pages/Assistants.tsx
@@ -2296,10 +2296,10 @@ export const DebugDrawer: React.FC<{
   useEffect(() => {
     if (!isOpen) return;
     if (!wsRef.current || wsRef.current.readyState !== WebSocket.OPEN) return;
-    // If core TTS-related settings changed while drawer stays open,
+    // If core runtime settings changed while drawer stays open,
     // reset the active WS session so the next launch uses new metadata.
     closeWs();
-  }, [isOpen, assistant.id, assistant.voice, assistant.speed]);
+  }, [isOpen, assistant.id, assistant.voice, assistant.speed, assistant.asrModelId]);
 
   useEffect(() => {
     if (!textTtsEnabled) {