OKX Lists AEON/USDT and AEON/USD and Separately Changes WebSocket Order Events

Key facts

• For AEON/USDT, deposits opened at 03:00 UTC on July 27, 2026, the call auction ran from 10:00 to 11:00, spot trading opened at 11:00, and withdrawals opened at 13:00.
• Market orders were unsupported for five minutes after the AEON/USDT call auction; when no stable index price exists, OKX uses closing-price-based limits.
• AEON/USD is a separate listing notice that states only a 12:00 UTC spot opening on July 27 and does not carry over the AEON/USDT auction or funding schedule.
• OKX may change N, H, X, Y, and Z or switch limit-price methods according to market conditions and directs users to the live market-rules page.
• The affected state: live event is pushed only after an order successfully enters the order book, with an approximately 1 ms delay.
• When a post_only placement fails because its price crosses the BBO, only state: canceled is pushed and state: live is omitted.
• The rpi change, including elp orders that will be deprecated, took effect in Demo Trading on July 21 and Live Trading on July 28; post_only and mmp_and_post_only changes were scheduled for mid-August in both environments.
• Other types such as limit, market, ioc, and fok retain their existing push behavior.

Key timeline

Who may be affected

• OKX users checking AEON/USDT deposit, auction, trading, or withdrawal status
• OKX users checking whether AEON/USD is available in their region
• API maintainers parsing post_only, mmp_and_post_only, rpi, or elp events from the order WebSocket channel

Impact analysis

The conditions in the three sources cannot be carried across one another. The AEON/USDT notice contains a funding and auction schedule plus initial listing price controls; the AEON/USD notice gives only a 12:00 UTC opening and a regional-availability reminder, so it does not establish the same auction, funding, or price-limit schedule. The WebSocket update has no causal connection to the AEON listings and instead changes an order-state machine: live arrives later for successful orders, while some failed orders terminate with canceled as their first event. Clients that require every canceled event to follow live must accept a terminal state without a prior live event while continuing to handle partially_filled, filled, and amendment sequences. Other order types are outside the announced change.

Risk notes

• AEON/USDT's initial price-limit method and market-order restriction affect order acceptance, and OKX may change related parameters without prior notice.
• The AEON/USD notice contains fewer conditions, so the AEON/USDT auction, funding times, and price-limit rules must not be assumed to apply.
• An API client that requires live before every canceled event may misclassify or miss the terminal state of a failed order under the new behavior.
• No exact post_only or mmp_and_post_only rollout date is stated, so official documentation and observed events should be monitored around deployment.
• This article covers official service and API changes and is not investment or trading advice.

This article is for information only and is not investment, legal, or tax advice. Digital assets are volatile and may result in loss of principal.

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