Polymarket - Scheduled Maintenance - CLOB – Maintenance details

All systems operational

Scheduled Maintenance - CLOB

Completed
Scheduled for July 24, 2026 at 4:00 AM – 5:04 AMUTC

Affects

Predictions

Under maintenance from 4:00 AM to 5:04 AM

Predictions Trading API (CLOB)

Under maintenance from 4:00 AM to 5:04 AM

Updates
  • Completed
    July 24, 2026 at 5:04 AMUTC
    Completed
    July 24, 2026 at 5:04 AMUTC

    Maintenance has completed successfully.

    Quick heads up: the txnHash change isn’t live yet. We held off enabling it in prod while we sort out an extra dependency first.
    No action needed on your end - you’re still getting transactionHashes in the response as usual, and there’s no latency impact from this.

    We’ll follow up with prod release timing once it’s confirmed.”

  • In progress
    July 24, 2026 at 4:00 AMUTC
    In progress
    July 24, 2026 at 4:00 AMUTC
    Maintenance is now in progress
  • Planned
    July 23, 2026 at 6:52 PMUTC
    Planned
    July 23, 2026 at 6:52 PMUTC

    Latency-focused release, with the introduction of our async-db pipeline.
    This cuts latency on the core matching engine, but it changes how you get transaction hashes after posting an order.

    What to expect:

    • Trading intermittent during maintenance, for up to 1.5h.

    • Brief post-only window after restart (2 min) before normal matching resumes. Cancels accepted.

    • There may be 503 errors during the maintenance, where trades would not be accepted

    Post-only: only orders explicitly set with postOnly: true are accepted. Regular limit orders without the flag, market orders, and any taking liquidity will be rejected. Cancels for existing orders will still go through.

    See POST /order API reference for the post-only flag.



    What's changing for developers

    Today, POST /order and POST /orders return transactionHashes inline on successful FAK/FOK matches. After this rollout, those endpoints won't return transactionHashes at all — you'll get tradeIDs instead.

    • tradeIDs behavior itself isn't changing: on a match you get tradeIDs back, on no match or failure you don't.

    • Websocket updates are unchanged. If you're already reading fills off the websocket, nothing to do here.


    What you need to do On CLOB client (TS / Python / Rust): it handles this for you — resolves transactions after posting and returns hashes, successful trades, and any failures. Just bump to the latest version. Custom API integration: if you depend on transactionHashes from the REST response, you'll need to resolve them yourself off tradeIDs — poll trades until each has a hash or comes back FAILED. Reference PRs: