Add ZeroGPU startup probe for HF free tier

app.py

@@ -28,6 +28,19 @@ from pr_review_agent.tools import (
     parse_pr_ref,
 )
 
+# Hugging Face's free Gradio Spaces run on ZeroGPU, which refuses to start unless a
+# @spaces.GPU function exists. Review Pilot only does network I/O (it calls a hosted
+# model), so it needs no GPU — this tiny no-op just satisfies that startup check.
+# Wrapped in try/except so local dev (where `spaces` isn't installed) is unaffected.
+try:  # pragma: no cover - only runs on Hugging Face Spaces
+    import spaces
+
+    @spaces.GPU(duration=15)
+    def _zerogpu_startup_probe() -> bool:
+        return True
+except Exception:
+    pass
+
 # Build the agent once at startup and reuse it across requests.
 _agent = build_agent()
 

requirements.txt

@@ -13,3 +13,4 @@ ollama==0.6.2          # ollama backend (local dev)
 
 mcp==1.29.1
 python-dotenv==1.2.3
+spaces