API Update: Introducing the 'instrumentID' and 'assetID' Fields to the Instrument and Wallet Assets Endpoints

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 2 Mar 2026, new fields, instrumentID and assetID, will be added to the BitMEX Instruments and Wallet Assets endpoints respectively.

Effective Date and Time: 2 March 2026 at 06:00 - 09:00 UTC

What is changing?

A new field, instrumentID, will be added to the response of the Instrument (available via the /instrument REST API endpoint and WebSocket API). This field contains a unique numeric identifier for each instrument.

Please refer to a snippet example of instrument in REST API or WebSocket API below:

"symbol": "XBTUSD",

"instrumentID": 1,

"maxOrderQty": 10000000,

"minPrice": 0.1,

"maxPrice": 1000000.0,

"lotSize": 100,

"tickSize": 0.1

A new field, assetID, will be added to the response of the Wallet Assets (available via the /wallet/assets REST API endpoint and WebSocket API). This field contains a unique numeric identifier for each asset.

Ple"symbol": "XBTUSD",

"instrumentID": 1,

"maxOrderQty": 10000000,

"minPrice": 0.1,

"maxPrice": 1000000.0,

"lotSize": 100,

"tickSize": 0.1ase refer to a snippet example of Wallet Assets response below:

"asset": "XBt",

"assetID": 1,

"currency": "XBt",

"name": "Bitcoin"

Why are we making this change?

The instrumentID and assetID fields are being introduced to support upcoming platform enhancements. They provide stable, unique numeric identifiers for instruments and assets respectively.

These are additive changes, meaning they introduce new fields 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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