chore: change default model to openrouter free llama3.1

app.py

@@ -12,7 +12,7 @@ DEFAULT_API_URL = "https://agents-course-unit4-scoring.hf.space"
 # ----- THIS IS WERE YOU CAN BUILD WHAT YOU WANT ------
 from smolagents import CodeAgent, LiteLLMModel, DuckDuckGoSearchTool
 import os
-import spaces  # 💡 重新引進 spaces 模組
+import spaces 
 
 @spaces.GPU
 def fake_gpu_function():
@@ -20,15 +20,17 @@ def fake_gpu_function():
 
 class BasicAgent:
     def __init__(self):
-        # 這裡只存儲 Token，保持乾淨
-        self.hf_token = os.getenv("HF_TOKEN")
+        self.openrouter_key = os.getenv("OPENROUTER_API_KEY")
+        
+        # 💡 將預設模型改為 OpenRouter 提供的免費 Llama 3.1 模型
+        self.model_id = os.getenv("HF_MODEL_ID", "openrouter/meta-llama/llama-3.1-8b-instruct:free")
 
     def __call__(self, question: str) -> str:
         try:
-            # 💡 真正的 Agent 在這裡臨時建立，且「絕對不要」加 @spaces.GPU 裝飾器
             model = LiteLLMModel(
-                model_id="huggingface/Qwen/Qwen2.5-72B-Instruct",
-                token=self.hf_token
+                model_id=self.model_id,
+                api_key=self.openrouter_key,
+                api_base="https://openrouter.ai/api/v1"
             )
             search_tool = DuckDuckGoSearchTool()
             agent = CodeAgent(tools=[search_tool], model=model)