Fix environment variable name from MODEL_ID to MODEL for Hugging Face Spaces

app.py

@@ -9,9 +9,15 @@ app = FastAPI(title="ImageGen API")
 
 # Choose a model that supports text->image via Inference API.
 # Using a model that works well with InferenceClient
-MODEL_ID = os.getenv("MODEL_ID", "stabilityai/stable-diffusion-xl-base-1.0")
+MODEL_ID = os.getenv("MODEL", "stabilityai/stable-diffusion-xl-base-1.0")
 HF_TOKEN = os.getenv("HF_TOKEN")  # set in Space Secrets
-client = InferenceClient(model=MODEL_ID, token=HF_TOKEN)
+
+# Initialize client with or without token
+if HF_TOKEN:
+    client = InferenceClient(model=MODEL_ID, token=HF_TOKEN)
+else:
+    # Use public inference API (may have rate limits)
+    client = InferenceClient(model=MODEL_ID)
 
 class GenReq(BaseModel):
     prompt: str