instruments Channel

Subscribe to real-time updates when the list of available trading instruments changes (new expirations added, instruments expired and removed).

Parameter	Required	Description
`market`	No	Base token filter: `"BTC"`, `"ETH"`, or `"ARB"`. If omitted, subscribes to all markets.

Single market:

{
  "type": "subscribe",
  "subscriptions": [
    {
      "channel": "instruments",
      "query": {
        "market": "BTC"
      }
    }
  ]
}

All markets:

{
  "type": "subscribe",
  "subscriptions": [
    {
      "channel": "instruments",
      "query": {}
    }
  ]
}

Event: instruments

Emitted when the list of available trading instruments is updated.

{
  "kind": "event",
  "type": "instruments",
  "timestamp_ms": 1777829658433,
  "data": {
    "updated_at": 1777829658433,
    "instruments": [
      "BTC_USDC-08MAY26-76000-C",
      "BTC_USDC-08MAY26-76000-P",
      "BTC_USDC-15MAY26-75000-C",
      "BTC_USDC-15MAY26-75000-P",
      "BTC_USDC-26JUN26-100000-C",
      "BTC_USDC-26JUN26-100000-P"
    ]
  },
  "subscription": {
    "channel": "instruments",
    "query": {
      "market": "BTC"
    }
  }
}

Field	Type	Description
`data.updated_at`	number	Unix timestamp in milliseconds of when the instrument list was last updated
`data.instruments`	string[]	Array of instrument names currently available for trading

Example: snapshot before vs after an expiry

Options expire at 08:00 UTC on their maturity date. The two events below show the same BTC subscription before and after the 04MAY26 expiry — the expired contract simply disappears from the array (no separate "removed" event).

Before — updated_at: 1777881540000 (2026-05-04T07:59:00Z):

{
  "data": {
    "updated_at": 1777881540000,
    "instruments": [
      "BTC_USDC-04MAY26-80500-C",
      "BTC_USDC-08MAY26-76000-C",
      "BTC_USDC-08MAY26-76000-P",
      "BTC_USDC-15MAY26-75000-C",
      "BTC_USDC-15MAY26-75000-P",
      "BTC_USDC-26JUN26-100000-C",
      "BTC_USDC-26JUN26-100000-P"
    ]
  }
}

After — updated_at: 1777881605000 (2026-05-04T08:00:05Z):

{
  "data": {
    "updated_at": 1777881605000,
    "instruments": [
      "BTC_USDC-08MAY26-76000-C",
      "BTC_USDC-08MAY26-76000-P",
      "BTC_USDC-15MAY26-75000-C",
      "BTC_USDC-15MAY26-75000-P",
      "BTC_USDC-26JUN26-100000-C",
      "BTC_USDC-26JUN26-100000-P"
    ]
  }
}

BTC_USDC-04MAY26-80500-C is gone from the second array — clients detect the removal by diffing against the previous snapshot.

Notes

Each event is a full snapshot, not a delta. The instruments array always contains the complete current list of active instruments for the market — there is no separate "added" or "removed" field.
Initial subscription provides a snapshot of all current instruments for the specified market(s)
Subsequent events are sent only when the instrument list changes — both when new instruments are added and when expired instruments are removed
To detect removals (e.g., expired contracts), diff the new instruments array against the previously received one — anything missing was removed
The instruments array contains options only (perpetuals are not published on this channel)
If no market is specified in the query, you'll receive separate events for each market (BTC, ETH, ARB)

Use Cases

Monitor when new option expirations become available
Track when instruments expire and are removed
Keep your trading application's instrument list synchronized with the exchange
Receive immediate notification when new trading instruments become available