400 Bad RequestDon't retry
Could not create api key
The Polymarket CLOB API returns this with HTTP 400. Polymarket doesn't document a cause beyond the message.
Retry? Don't retry
Sending the same request again returns the same error. Change the request first.
Returned by
- POST /auth/api-key 9,000 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 "Could not create api key" in msg:
raise ValueError(msg) # fix the request, don't retryRelated 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.