503 Service UnavailableWait for the exchange
Trading is currently cancel-only. New orders are not accepted, but cancels are allowed.
The exchange is in cancel-only mode. You can cancel existing orders but cannot place new orders.
The exchange is accepting cancels but no new orders. Cancel what you need to and stop opening positions until it lifts.
Retry? Wait for the exchange
The exchange is in a restricted mode. The same order will keep failing until the mode lifts; there is nothing to fix on your side.
Returned by
- POST /order 5,000 req / 10s
Handling it in code
The CLOB API returns errors as {"error": "..."}. It also rewrites status codes by message, so branch on the text: anything containing "not found" becomes 404 and anything containing "unauthorized" becomes 401.
r = session.post(url, json=payload, headers=headers)
if r.status_code >= 400:
msg = r.json().get("error", "")
if "Trading is currently cancel-only. New orders are not accepte" in msg:
pause_trading()Related errors
For errors Polymarket doesn't document, like "order manager not ready" or 403s from the edge, see the full error guide.
Message and status from Polymarket's error reference, synced 2026-10-04.