Allow empty POST body on reset

server/app.py

@@ -4,7 +4,7 @@ from threading import Lock
 from uuid import uuid4
 from typing import Any
 
-from fastapi import FastAPI, HTTPException, WebSocket, WebSocketDisconnect
+from fastapi import Body, FastAPI, HTTPException, WebSocket, WebSocketDisconnect
 from fastapi.responses import HTMLResponse, RedirectResponse
 from pydantic import BaseModel, ConfigDict
 
@@ -75,9 +75,10 @@ def root() -> RedirectResponse:
 
 
 @app.post("/reset")
-def reset(request: ResetRequest) -> dict[str, Any]:
-    session_id, env = manager.create_or_reuse(request.session_id, request.task_id)
-    result = env.reset(request.task_id)
+def reset(request: ResetRequest | None = Body(default=None)) -> dict[str, Any]:
+    request = request or ResetRequest()
+    session_id, env = manager.create_or_reuse(request.session_id, request.task_id)
+    result = env.reset(request.task_id)
     return _step_payload(result, session_id)