diff --git a/dsh/app.py b/dsh/app.py
index 0f545a7..8bbb454 100644
--- a/dsh/app.py
+++ b/dsh/app.py
@@ -34,7 +34,7 @@ BASE_DIR = Path(__file__).resolve().parent
 USER_NAME = os.getenv("DSH_USER", "user")
 DEFAULT_SLOT = os.getenv("DSH_SLOT", "Welcome to DeepSeek Harness")
 LLM_BASE = os.getenv("DSH_LLM_BASE", "http://192.168.20.13:20129/v1")
-LLM_MODEL = os.getenv("DSH_LLM_MODEL", "auto/best-chat")
+LLM_MODEL = os.getenv("DSH_LLM_MODEL", "auto/best-fast")
 LLM_KEY = os.getenv("DSH_LLM_KEY", "")
 SYSTEM_PROMPT = os.getenv(
     "DSH_SYSTEM_PROMPT",
@@ -248,8 +248,11 @@ async def chat(message: Annotated[str, Form()],
         else:
             base = LLM_BASE
             key = LLM_KEY
+            active_model = session.get("model") or LLM_MODEL
+            if active_model not in MODEL_CHOICES:
+                active_model = LLM_MODEL
             payload = {
-                "model": session.get("model") or LLM_MODEL,
+                "model": active_model,
                 "messages": [{"role": "system", "content": SYSTEM_PROMPT}] + hist,
                 "stream": True,
                 "temperature": 0.7,
@@ -283,6 +286,8 @@ async def chat(message: Annotated[str, Form()],
             return
         if full:
             hist.append({"role": "assistant", "content": "".join(full)})
+        else:
+            yield f"data: {json.dumps({'e': 'Model returned no response — try auto/best-chat or auto/best-fast.'})}\n\n"
         save_session(sid, hist, session.get("model"))  # always persist user turn + chosen model
 
     return StreamingResponse(
@@ -322,7 +327,7 @@ async def generate_image(prompt: Annotated[str, Form()]) -> dict:
 
 
 
-MODEL_CHOICES = ["auto/best-chat", "auto/best-fast", "auto/best-reasoning",
+MODEL_CHOICES = ["auto/best-chat", "auto/best-fast",
                  "auto/best-coding", "auto/best-vision"]
 
 
diff --git a/dsh/docker-compose.yml b/dsh/docker-compose.yml
index 17a2e7f..a145195 100644
--- a/dsh/docker-compose.yml
+++ b/dsh/docker-compose.yml
@@ -22,7 +22,7 @@ x-dsh-common: &common
     - /tmp
   environment: &env-base
     DSH_LLM_BASE: http://192.168.20.13:20129/v1
-    DSH_LLM_MODEL: auto/best-chat
+    DSH_LLM_MODEL: auto/best-fast
     DSH_HISTORY_DIR: /data
     DSH_VISION_KEY: ${DSH_VISION_KEY:-}
     DSH_VISION_MODEL: openai/gpt-5