Fix: add missing StepResponse class

app.py

@@ -27,6 +27,13 @@ class ResetRequest(BaseModel):
     task: Optional[str] = None  # Support both task_id and task
 
 
+class StepResponse(BaseModel):
+    observation: MLOpsObservation
+    reward: float
+    done: bool
+    info: Dict[str, Any]
+
+
 @app.post("/reset", response_model=MLOpsObservation)
 async def reset(req: ResetRequest):
     global _http_env