Update app.py

app.py

@@ -14,7 +14,7 @@ app = FastAPI(title="Agent Sandbox API")
 class IncommingMail(BaseModel):
     data: List[Dict[str, Any]]   # requires a "data" field in JSON
     timestamp: str = datetime.utcnow().strftime("%Y%m%dT%H%M%SZ")
-    id: str = uuid.uuid4())[:5]
+    id: str = uuid.uuid4().hex[:5]
     
     @property 
     def file_path(self):