Gate Announcement on USDT Perpetual Contract Order Quantity Field Type Changes and Feature Rollout Plan

Changes to Futures Size-Related Field Types
To enhance the flexibility of future trading and fully support fractional quantity orders, Gate will implement a phased upgrade for the USDT perpetual contract APIs. This upgrade will affect the parsing logic of order quantity (size) related fields in both REST API and WebSocket. Please assess and adjust your strategy logic in advance according to the phased plan to ensure your trading remains unaffected.

1.1 Upgrade Plan Overview (Divided into 3 Phases)

1. Phase 1: Field Type Compatibility Upgrade (Launched on December 9, 2025)

• Completed underlying data structure adjustments.
• Modified the data type of contract quantity-related fields from Integer to String.
• The system is currently in compatibility mode. By including the X-Gate-Size-Decimal field in the request header, compatibility processing for the contract lot quantity field is achieved.

Header Parameter	Description	Remarks
X-Gate-Size-Decimal = 1	size-related field types change from Integer to String	1. Supports receiving decimal data.
X-Gate-Size-Decimal = 0 Or, not using this header field By default, this field is unused.	size-related field types remain Integer	1. Does not support receiving decimal data. 2. Precision handling - Truncates towards zero (downwards).

• If the X-Gate-Size-Decimal header is not set, the size field will continue to accept and return the Integer type by default.

2. Phase 2: Fractional Quantity Ordering Capability Launch

1. The system capability for fractional lot ordering on USDT perpetual contracts is scheduled to launch on December 30, 2025. During this phase, only the underlying system capabilities and API support will be enabled. No contracts will be practically opened for fractional lot ordering at this time, and the actual order placement rules for users will remain unchanged.

2. Starting from late January 2026, the fractional lot ordering functionality will be gradually rolled out to contracts. Specific contracts and timelines for the rollout will be announced by the platform in subsequent notices.

3. For users still using the old field type without adaptation, the following issues may arise:

• Abnormal precision parsing in contract depth data.
• Inconsistent order precision.
• Abnormal precision in filled orders.

Therefore, all API users are reminded to complete field type adaptation as much as possible by the end of January 2026.

3. Phase 3: Full Enablement for All USDT-Margined Perpetual Contracts and Mandatory Migration to String Field Types

1. All contract trading pairs will fully support fractional lot order placement.
2. At a specified time, the system will default to returning String type and adjust the default value of the header (X-Gate-Size-Decimal), switching the default parsing behavior from 0 to 1 to provide a short transition period for users who have not yet completed adaptation.
3. After the transition period, the X-Gate-Size-Decimal header field will be officially deprecated, and its configuration will no longer take effect.
4. All order quantity-related fields will uniformly use the String type to ensure precision and compatibility. The legacy Integer type will no longer be supported.
5. The specific effective date will be announced in advance via official notice. Please ensure all adaptations are completed beforehand.

1.2 Detailed Explanation of Phase 1 Upgrade

1.Both REST and WebSocket APIs have introduced a new header field, X-Gate-Size-Decimal , to control the precision of quantity-related fields.

Header Parameter	Description	Remarks
X-Gate-Size-Decimal = 1	size-related field types change from Integer to String	1. Supports receiving decimal data.
X-Gate-Size-Decimal = 0 Or, not using this header field By default, this field is unused.	size-related field types remain Integer	1. Does not support receiving decimal data. 2. Precision handling - Truncates towards zero (downwards).

Recommendation: Clients should promptly adapt to the change in contract quantity field types. Once the contract officially supports fractional quantity ordering, they can quickly experience and utilize this functionality.

2.Reference Example for Setting Header

Rest

# Set request headers 
headers = 
{ 
'KEY': API_KEY,
'Timestamp': timestamp,
'SIGN': signature,
# Enable decimal size
'X-Gate-Size-Decimal': '1',
'Content-Type': 'application/json',
'Accept': 'application/json'
}

Websocket

# Set request headers
# Enable decimal size
headers['X-Gate-Size-Decimal'] = '1'

1.3 Future Size Field Type Changes

1. Rest Related Fields

Interface Type	Endpoint	Field	Remarks
Public	1. Query All Futures Info GET /futures/settle/contracts 2. Query Single Future Info GET /futures/settle/contracts/contract	Minimum order size allowed by the contract 'order_size_min' Maximum order size allowed by the contract 'order_size_max' Historical cumulative trading volume 'trade_size' Current total long position size 'position_size'	1. Using header field X-Gate-Size-Decimal=1 , the type of the above fields will change from Integer to String . 2. Clients need to adjust the acceptance type for these fields.
Public	1. Query futures market depth information GET /futures/settle/order_book	Size 's'
Public	1. Futures market transaction records GET /futures/settle/trades	Trading Size 'size'
Public	1. Futures market K-line chart GET /futures/settle/candlesticks	size volume (contract size) 'v'
Public	1. Futures statistics GET /futures/settle/contract_stats	Long liquidation size (contracts) 'long_liq_size' Short liquidation size (contracts) 'short_liq_size' Total open interest size (contracts) 'open_interest' Top trader long/short position ratio 'top_lsr_size' Top trader long size 'top_long_size' Top trader short size 'top_short_size' Top taker long size 'long_taker_size' Top taker short size 'short_taker_size'
Public	1. Query liquidation order history GET /futures/settle/liq_orders	Position size 'size' Liquidation order price 'order_size' System liquidation order maker size 'left'
Private	1. Get user position list GET /futures/settle/positions 2. Get single position information GET /futures/settle/positions/contract 3. Update position margin POST /futures/settle/positions/contract/margin 4. Update position leverage POST /futures/settle/positions/contract/leverage 5. Switch Position Margin Mode POST /futures/settle/positions/cross_mode 6. Switch Between Cross and Isolated Margin Modes Under Hedge Mode POST /futures/settle/dual_comp/positions/cross_mode 7. Update position risk limit POST /futures/settle/positions/contract/risk_limit 8. Set position mode POST /futures/settle/dual_mode 9. Get position information in Hedge Mode GET /futures/settle/dual_comp/positions/contract 10. Update position margin in Hedge Mode POST /futures/settle/dual_comp/positions/contract/margin 11. Update position leverage in Hedge Mode POST /futures/settle/dual_comp/positions/contract/leverage 12. Update position risk limit in Hedge Mode POST /futures/settle/dual_comp/positions/contract/risk_limit	Position Size 'size'
Private	1. Place futures order POST /futures/settle/orders 2. Query futures order list GET /futures/settle/orders 1. Cancel all orders with 'open' status DELETE /futures/settle/orders 2. Query futures order list by time range GET /futures/settle/orders_timerange 3. Place batch futures orders POST /futures/settle/batch_orders 4. Query single order details GET /futures/settle/orders/order_id 5. Cancel single order DELETE /futures/settle/orders/order_id 6. Amend single order PUT /futures/settle/orders/order_id 7. Level-based BBO Contract Order Placement POST /futures/settle/bbo_orders	Trading quantity. 'size' Display size for iceberg orders 'iceberg' Unfilled quantity 'left'
Private	1. Query personal trading records GET /futures/settle/my_trades 2. Query personal trading records by time range GET /futures/settle/my_trades_timerange	Trading Size 'size' Size of closed positions: 'close_size'
Private	1. Query position close history GET /futures/settle/position_close	Max Trade Size 'max_size' Cumulative closed position volume 'accum_size'
Private	1. Query liquidation history GET /futures/settle/liquidates	Position Size 'size' Liquidation Order Pending Size 'left'
Private	1. Query ADL auto-deleveraging order information GET /futures/settle/auto_deleverages	Trade Size 'trade_size' Position Size After ADL 'position_size'
Private	1. Query auto order list GET /futures/settle/price_orders 2. Cancel all auto orders DELETE /futures/settle/price_orders 3. Query single auto order details GET /futures/settle/price_orders/order_id 4. Cancel single auto order DELETE /futures/settle/price_orders/order_id 5. Modify a Single Auto Order PUT /futures/settle/price_orders/order_id	New field: 'amount' (string type).	1. New field: amount (string type). 2. The original field size (int ) and the new field amount (string) will be compatible.

2. Websocket Related Fields

Channel Type	Channel	Fields	Remarks
Public	1. Public Trades Channel futures.trades	Filled Size 'size'	1. Using header field X-Gate-Size-Decimal=1 , the type of the above fields will change from Integer to String . 2. Clients need to adjust the acceptance type for these fields.
Public	1. Ticker Channel futures.tickers	Total Size 'total_size'
Public	1. BBO Channel futures.book_ticker	Best Bid Size 'A' Best Ask Size 'B'
Public	1. Depth Update Channel futures.order_book_update	Ask Side Pending Size 'a.s' Bid Side Pending Size 'b.s'
Public	1. Full Depth Channel futures.order_book	Ask Side Pending Size a.s Bid Side Pending Size b.s
Public	1. Depth V2 Channel futures.obu	[price,size] 'size' May push decimal size
Public	1. Candlestick Channel futures.candlesticks	Volume 'v'
Public	1. Public Liquidations Channel futures.public_liquidates	Liquidation Order Size 'size'
Public	1. Contract Statistics Channel futures.contract_stats	Long Liquidation Size 'long_liq_size' Short Liquidation Size 'short_liq_size' Total Open Interest 'open_interest'
Private	1. Private Orders Channel futures.orders	Iceberg Display Size 'iceberg' Remaining Tradeable Size 'left' Order Size 'size'
Private	1. Private Trades Channel futures.usertrades	Filled Size 'size'
Private	1. Private ADL Channel futures.auto_deleverages	Position Size 'position_size' Trade Size 'trade_size'
Private	1. Positions Channel futures.positions	Position Size 'size'
Private	1. Price Trigger Orders Channel futures.autoorders	New field: 'amount' (string type).	1. New field: amount (string type). 2. The original field size ( Integer type) and the new field amount (String) will be compatible.
Private	1. Liquidation Orders Channel futures.liquidates	Remaining Tradeable Size 'left' Position Size 'size'	1. Using header field X-Gate-Size-Decimal=1 , the type of the above fields will change from Integer to String . 2. Clients need to adjust the acceptance type for these fields.
Private	1. Order Placement futures.order_place 2. Batch Order Placement futures.order_batch_place 3. Order Cancellation futures.order_cancel 4. Batch Cancel by ID futures.order_cancel_cp 5. Order Amendment futures.order_amend 6. Query Order List futures.order_list 7. Query Order Details futures.order_status	Order Size 'size' Remaining Tradeable Size 'left' Iceberg Display Quantity 'iceberg'

1.4 Querying Future Information Supporting Decimal Order Placement

1.Set Header X-Gate-Size-Decimal=1
2.Request the Contract Information endpoint

curl --location 'https://api.gateio.ws/api/v4/futures/usdt/contracts' \ 
--header 'X-Gate-Size-Decimal: 1'

3.Return Field order_size_min: If the value is a decimal, it indicates that the corresponding futures support decimal order placement.

1.5 Additional Information

API Update Log: https://www.gate.com/docs/developers/apiv4/en/#changelog
For any questions, please contact API technical support or refer to the API documentation. Thank you for your support and understanding

Gate Team December 18, 2025 **Gateway to Crypto** Trade over 4,400 cryptocurrencies safely, quickly, and easily on Gate **Take Action Now** Sign up and claim up to $10,000 in welcome rewards Invite friends and earn a 40% commission **Stay Connected** Visit Gate's official website Download the Gate App | Desktop Follow us on X (Twitter) to get more bonuses Join our Telegram community to discuss trending topics Engage with our global community for the latest insights **Transparency & Security** Check our 100% Proof of Reserves