Update app.py

app.py

@@ -64,10 +64,8 @@ GROQ_MODELS = [
 ]
 
 OPENROUTER_MODELS = [
-    "nvidia/nemotron-3.5-content-safety:free",
-    "qwen/qwen3.7-plus",
-    "microsoft/mai-transcribe-1.5",
-    "google/gemini-embedding-2"
+    "nvidia/nemotron-3-ultra-550b-a55b:free",
+    "nvidia/nemotron-3.5-content-safety:free"
 ]
 
 # --- Reactive State Event Handlers ---
@@ -103,12 +101,10 @@ def call_llm(provider, api_key, model_choice, system_prompt, history_messages):
     elif provider == "OpenRouter":
         headers = {"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"}
         openrouter_model_map = {
-            "nvidia/nemotron-3.5-content-safety:free": "nvidia/nemotron-3.5-content-safety:free",
-            "qwen/qwen3.7-plus": "qwen/qwen3.7-plus",
-            "microsoft/mai-transcribe-1.5": "microsoft/mai-transcribe-1.5",
-            "google/gemini-embedding-2": "google/gemini-embedding-2"
+            "nvidia/nemotron-3-ultra-550b-a55b:free": "nvidia/nemotron-3-ultra-550b-a55b:free",
+            "nvidia/nemotron-3.5-content-safety:free": "nvidia/nemotron-3.5-content-safety:free"
         }
-        target_model = openrouter_model_map.get(model_choice, "nvidia/nemotron-3.5-content-safety:free")
+        target_model = openrouter_model_map.get(model_choice, "nvidia/nemotron-3-ultra-550b-a55b:free")
         
         payload = {
             "model": target_model,