API Update: Introducing origClOrdID and changing clOrdID in executions
At BitMEX, we are committed to continually improving our platform and its infrastructure to support advanced trading capabilities for our users. As part of this ongoing effort, we are announcing an update to our REST and WebSocket APIs.
From 26 January 2026, a new field, origClOrdId, will be added to the BitMEX Execution response.
Effective Date and Time: 26 January 2026 at 06:00 – 09:00 UTC
What is changing?
A new field, origClOrdID, will be added to the Execution response (available via the /execution and /order REST API endpoint and WebSocket API). origClOrdID will hold the previous clOrdID when the order is replaced, otherwise the currently effective clOrdID.
Cancellation responses will also include origClOrdID which will always be the currently effective clOrdID value.
Please refer to a snippet example in the REST API or WebSocket API below:
/execution
"execID":"2e8f42c4-1b86-291b-c371-87a2c503b1a8",
"orderID": "2e8f42c4-1b86-291b-c371-899999999998",
"origClOrdID": "id1",
"clOrdID": "id2",
"account": 1234567,
"symbol":"XBTUSDT",
Additionally the content of clOrdID will change in some cases. clOrdID will reflect the value of the amend request when rejecting, whereas before it was the current value. In all other cases it stays as it is today, which is the current effective value for the order.
Why are we making this change?
We are aligning with common standards, such as FIX, to make it easier to track chains of amends.
This is an additive change, meaning it introduces a new field without removing any existing data. Most integrations should be unaffected.
If you have any questions about these upcoming changes, please contact Support.
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