Spot REST API

Spot Market Endpoints

Query symbols

GET ${SPOT_ENDPOINT}/markets/symbols

Get trading rules and symbol information for all spot symbols.

curl -X GET ${SPOT_ENDPOINT}/markets/symbols \
  -H 'Accept: application/json'

Query Parameters

Name	Type	Required	Description
symbol	string	false	Symbol name, e.g. vBTC_vUSDC

Response

Field	Type	Description
data	Array<SpotSymbol>	Response data when code is 0. See SpotSymbol in Schema

Query coins

GET ${SPOT_ENDPOINT}/markets/coins

Get information for all coins.

curl -X GET ${SPOT_ENDPOINT}/markets/coins \
  -H 'Accept: application/json'

Query Parameters

Name	Type	Required	Description
coin	string	false	Coin name, e.g. vBTC

Response

Field	Type	Description
data	Array<SpotCoin>	Response data when code is 0. See SpotCoin in Schema

Query tickers

GET ${SPOT_ENDPOINT}/markets/tickers

Get 24hr rolling window price change statistics for all symbols.

curl -X GET ${SPOT_ENDPOINT}/markets/tickers \
  -H 'Accept: application/json'

Query Parameters

Name	Type	Required	Description
symbol	string	false	Symbol name, e.g. vBTC_vUSDC

Response

Field	Type	Description
data	Array<SpotTicker>	Response data when code is 0. See SpotTicker in Schema

Query mini tickers

GET ${SPOT_ENDPOINT}/markets/miniTickers

Get 24hr rolling window price change statistics for all symbols.

curl -X GET ${SPOT_ENDPOINT}/markets/miniTickers \
  -H 'Accept: application/json'

Query Parameters

Name	Type	Required	Description
symbol	string	false	Symbol name, e.g. vBTC_vUSDC

Response

Field	Type	Description
data	Array<MiniTicker>	Response data when code is 0. See MiniTicker in Schema

Query book tickers

GET ${SPOT_ENDPOINT}/markets/bookTickers

Best price/qty on the order book for symbols.

curl -X GET ${SPOT_ENDPOINT}/markets/bookTickers \
  -H 'Accept: application/json'

Query Parameters

Name	Type	Required	Description
symbol	string	false	Symbol name, e.g. vBTC_vUSDC

Response

Field	Type	Description
data	Array<BookTicker>	Response data when code is 0. See BookTicker in Schema

Query order book

GET ${SPOT_ENDPOINT}/markets/{symbol}/orderbook

Get order book depth for a symbol.

curl -X GET "${SPOT_ENDPOINT}/markets/vBTC_vUSDC/orderbook?limit=20" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
symbol	string	true	Symbol name, e.g. vBTC_vUSDC

Query Parameters

Name	Type	Required	Description
limit	uint32	false	Depth limit. Default: 10, Max: 1000

Response

Field	Type	Description
data	OrderBook	Response data when code is 0. See OrderBook in Schema

Query candles/klines

GET ${SPOT_ENDPOINT}/markets/{symbol}/klines

Get candlestick/kline data for a symbol.

curl -X GET "${SPOT_ENDPOINT}/markets/vBTC_vUSDC/klines?interval=1h&limit=100" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
symbol	string	true	Symbol name, e.g. vBTC_vUSDC

Query Parameters

Name	Type	Required	Description
interval	string	true	Kline interval (case-sensitive): 1m, 3m, 5m, 15m, 30m, 1h, 4h, 6h, 8h, 12h, 1d, 3d, 1w, 1M. Note: day/week use lowercase (1d, 3d, 1w); only month is uppercase (1M).
startTime	uint64	false	Start time in milliseconds
endTime	uint64	false	End time in milliseconds
limit	uint32	false	Number of klines to return. Default: 500, Max: 1500

Response

Field	Type	Description
data	Array<RPCKline>	Response data when code is 0. See RPCKline in Schema

Query recent trades

GET ${SPOT_ENDPOINT}/markets/{symbol}/trades

Get recent public trades for a symbol.

curl -X GET "${SPOT_ENDPOINT}/markets/vBTC_vUSDC/trades?limit=50" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
symbol	string	true	Symbol name, e.g. vBTC_vUSDC

Query Parameters

Name	Type	Required	Description
limit	uint32	false	Number of trades to return. Default: 50, Max: 500

Response

Field	Type	Description
data	Array<Trade>	Response data when code is 0. See Trade in Schema

Spot Accounts Endpoints

Query balances

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/balances

Get current account balance.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/balances" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.

Response

Field	Type	Description
data	SpotAccountBalances	Response data when code is 0. See SpotAccountBalances in Schema

Query open orders

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/orders

Get all open orders for an account.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/orders?symbol=vBTC_vUSDC" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
symbol	string	false	Filter by symbol name
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.

Response

Field	Type	Description
data	SpotAccountOpenOrder	Response data when code is 0. See SpotAccountOpenOrder in Schema

Query state for frontend

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/state

Get comprehensive account state for UI initialization. Includes balances, open orders, active TWAP orders, and sync metadata.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/state" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.

Response

Field	Type	Description
data	WsSpotState	Response data when code is 0. See WsSpotState in Schema

Query API Keys

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/api-keys

Get list of API keys.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/api-keys" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.
name	string	false	The name of the API key.

Response

Field	Type	Description
data	Array<APIKey>	Response data when code is 0. See APIKey in Schema

Query TWAP Orders

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/twaps

Get active TWAP orders for an account.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/twaps?symbol=vBTC_vUSDC" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.
symbol	string	false	Symbol name, e.g. vBTC_vUSDC.

Response

Field	Type	Description
data	AccountTwapOrders	Response data when code is 0. See AccountTwapOrders in Schema

Query fee rate

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/fee-rate

Get the current maker/taker fee rates for the account, including fee tier, staking tier, and maker rebate tier. Optionally pass a symbol to include the symbol-level fee discount.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/fee-rate?symbol=vBTC_vUSDC" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.
symbol	string	false	Symbol name, e.g. vBTC_vUSDC. When provided, the symbol-level fee discount is applied.

Response

Field	Type	Description
data	FeeRate	Response data when code is 0. See FeeRate in Schema

Query order history

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/orders/history

Get historical orders (filled, canceled, expired) for an account.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/orders/history?symbol=vBTC_vUSDC" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.
symbol	string	false	Filter by symbol name
startTime	uint64	false	Start time in milliseconds
endTime	uint64	false	End time in milliseconds
limit	uint32	false	Number of orders to return. Default: 50, Max: 500

Response

Field	Type	Description
data	Array<SpotOrder>	Response data when code is 0. See SpotOrder in Schema

Query user trades

GET ${SPOT_ENDPOINT}/accounts/{userAddress}/trades

Get historical trade executions for an account.

curl -X GET "${SPOT_ENDPOINT}/accounts/0x0123456789070ce8f0d6bab722103d12674bc257/trades?symbol=vBTC_vUSDC&limit=100" \
  -H 'Accept: application/json'

Path Parameters

Name	Type	Required	Description
userAddress	HexString	true	User EVM address

Query Parameters

Name	Type	Required	Description
accountID	uint64	false	The sub-account ID of the user. Primary account ID is used by default.
symbol	string	false	Filter by symbol name
orderID	uint64	false	Filter by order ID
startTime	uint64	false	Start time in milliseconds
endTime	uint64	false	End time in milliseconds
limit	uint32	false	Number of trades to return. Default: 100, Max: 1000

Response

Field	Type	Description
data	Array<UserTrade>	Response data when code is 0. See UserTrade in Schema

Transfer asset to EVM or perps

POST ${SPOT_ENDPOINT}/accounts/transfers

Transfer assets between accounts.

• Auth: signed write

curl -X POST ${SPOT_ENDPOINT}/accounts/transfers \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <TransferAssetRequest>

Request Body

See TransferAssetRequest in Schema

Additional Information:

• Number of decimal places of transfer.amount should not exceed coin precision. That is transfer.amount % 10^{-coin.precision} = 0.

• The transfer.amount must be a positive value.

• Transfer asset to EVM chain: transfer.toAccountID=999, transfer.type=EVM_WITHDRAW

• Transfer asset to perps chain: transfer.toAccountID=999, transfer.type=PERPS_WITHDRAW

• Internal transfer between spot chains is not supported yet.

Response

Field	Type	Description
data	ResponseData	Response data when code is 0.

• ResponseData

  Name	Type	Required	Description
  id	uint64	true	Identifier for this transfer request. Same as id in TransferAssetRequest.

Remove API Key

DELETE ${SPOT_ENDPOINT}/accounts/api-keys

• Auth: signed write

curl -X DELETE ${SPOT_ENDPOINT}/accounts/api-keys \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <RevokeAPIKeyRequest>

Request Body

See RevokeAPIKeyRequest in Schema

Additional Information:

• The api.name must match ^[0-9a-zA-Z_-]{1,36}$.

• The api.name cannot be default, which is reserved for user EVM address.

Response

• No endpoint-specific data payload.

Spot Trading Endpoints

Place multiple orders

POST ${SPOT_ENDPOINT}/trade/orders/batch

Submit multiple orders atomically.

• Auth: signed write

curl -X POST ${SPOT_ENDPOINT}/trade/orders/batch \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <BatchNewOrderParams>

Request Body

Find BatchNewOrderRequest and BatchNewOrderItem in Schema

Additional Information:

• The batch cannot be empty.

• The length of batch should less than or equals to 100.

• builder, if provided, attaches a builder fee to every order in the batch. See BuilderParams.

• Basic Validation

  • The order[i].clOrdID must match ^[0-9a-zA-Z_-]{1,36}$.

  • order[i].clOrdID must be unique among open orders. Reuse is allowed only after the previous order is filled.

  • For limit order

    • order[i].timeInForce can be GTC, IOC, GTX.

    • provide both order[i].price and order[i].quantity, do not send order[i].funds.

  • For market order

    • order[i].timeInForce must be IOC.

    • Provide either order[i].quantity or order[i].funds, not both. order[i].funds only available for market buy orders.

    • order[i].price optional for slippage protection.

  • The order will be rejected if basic validation failed.

• Price filter

  • The decimal precision of order price should not exceed symbol.pricePrecision. That is order[i].price % 10^{-symbol.pricePrecision} = 0.

  • The order price must be multiple of symbol.tickSize. That is order[i].price % symbol.tickSize = 0.

  • If symbol.minPrice is not 0, the order price should greater than or equals to symbol.minPrice.

  • If symbol.maxPrice is not 0, the order price should less than or equals to symbol.maxPrice.

  • The order will be rejected if price filter check failed.

• Lot size filter

  • The decimal precision of order quantity should not exceed symbol.quantityPrecision. That is order[i].quantity % 10^{-symbol.quantityPrecision} = 0.

  • The order quantity must be multiple of symbol.stepSize. That is order[i].quantity % symbol.stepSize = 0.

  • If symbol.minQuantity is not 0, the order quantity should greater than or equals to symbol.minQuantity.

  • If symbol.maxQuantity is not 0, the order quantity should less than or equals to symbol.maxQuantity.

  • The order will be rejected if lot size filter check failed.

• Market lot size filter

  • This is an additional check for market order.

  • If symbol.marketMinQuantity is not 0, the order quantity should greater than or equals to symbol.marketMinQuantity.

  • If symbol.marketMaxQuantity is not 0, the order quantity should less than or equals to symbol.marketMaxQuantity.

  • The order will be rejected if market lot filter check failed.

• Notional filter

  • The gateway skips this filter for vault and liquidator accounts.

  • For limit order, the order notional is order[i].price * order[i].quantity.

  • For market order with order[i].funds provided, the order notional is order[i].funds.

  • For market order without order[i].funds, the order notional is estimated as symbol.lastTradePrice * order[i].quantity.

  • If symbol.minNotional is not 0, the order notional should greater than or equals to symbol.minNotional.

  • If symbol.maxNotional is not 0, the order notional should less than or equals to symbol.maxNotional.

  • The order will be rejected if notional filter check failed.

• Other price limitation

  • for limit buy orders, the order price should less than or equal to symbol.lastTradePrice * (1 + symbol.buyLimitUpRatio). Otherwise, the order is rejected.

  • for limit sell orders, the order price should greater than or equal to symbol.lastTradePrice * (1 - symbol.sellLimitDownRatio). Otherwise, the order is rejected.

  • for market buy orders without price, the final execution price is bounded by symbol.lastTradePrice * (1 + symbol.marketDeviationRatio). If price is provided, the final execution price is bounded by min(order[i].price, symbol.lastTradePrice * (1 + symbol.marketDeviationRatio))

  • for market sell orders without price, the final execution price is bounded by symbol.lastTradePrice * (1 - symbol.marketDeviationRatio). If price is provided, the final execution price is bounded by max(order[i].price, symbol.lastTradePrice * (1 - symbol.marketDeviationRatio))

Response

Field	Type	Description
data	Array<ResponseData>	Response data when code is 0.

• ResponseData

  Name	Type	Required	Description
  code	int32	true	Response status code, 0 for success and other code for failure.
  clOrdID	string	true	Client order id; same as clOrdID in BatchNewOrderItem.
  error	string	false	Error description for individual order. Only provided when code is not 0.
  orderID	uint64	false	Order id. Only provided when the code is 0.

The length of the response result array is usually the same as the length of batched request.

Important: Some errors are a deterministic function of the payload itself, and these are instead returned earlier as part of pre-validation. In this case, only one error is returned for the entire payload, as some of these errors do not apply to a specific order.

For API users that use batching, it's recommended to handle the case where a single error is returned for a batch of multiple orders. In this case, the response could be duplicated n times before being sent to the callback function, as the whole batch was rejected for this same reason.

Place a new TWAP order

POST ${SPOT_ENDPOINT}/trade/twaps

Place a new spot TWAP order.

• Auth: signed write

curl -X POST ${SPOT_ENDPOINT}/trade/twaps \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <NewTwapOrderRequest>

Request Body

See NewTwapOrderRequest in Schema

Response

Field	Type	Description
data	TwapOrderResponse	Response data when code is 0. See TwapOrderResponse in Schema

Cancel multiple orders

DELETE ${SPOT_ENDPOINT}/trade/orders/batch

Submit multiple order cancellations atomically.

• Auth: signed write

curl -X DELETE ${SPOT_ENDPOINT}/trade/orders/batch \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <BatchCancelOrderRequest>

Request Body

Find BatchCancelOrderRequest and BatchCancelOrderItem in Schema

Additional Information:

• The batch cannot be empty.

• The length of batch should less than or equals to 100.

Response

Field	Type	Description
data	Array<ResponseData>	Response data when code is 0.

• ResponseData

  Name	Type	Required	Description
  code	int32	true	Response status code, 0 for success and other code for failure.
  clOrdID	string	true	Client order id; same as clOrdID in BatchCancelOrderItem.
  error	string	false	Error description for individual order. Only provided when code is not 0.
  orderID	uint64	false	Order id. Only provided when the code is 0.
  origClOrdID	string	false	Client order id of the canceled order. Only provided when code is 0.

The length of the response result array is usually the same as the length of batched request.

Important: Some errors are a deterministic function of the payload itself, and these are instead returned earlier as part of pre-validation. In this case, only one error is returned for the entire payload, as some of these errors do not apply to a specific order.

For API users that use batching, it's recommended to handle the case where a single error is returned for a batch of multiple orders. In this case, the response could be duplicated n times before being sent to the callback function, as the whole batch was rejected for this same reason.

Cancel a TWAP order

DELETE ${SPOT_ENDPOINT}/trade/twaps

Cancel a spot TWAP order.

• Auth: signed write

curl -X DELETE ${SPOT_ENDPOINT}/trade/twaps \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <CancelTwapOrderRequest>

Request Body

See CancelTwapOrderRequest in Schema

Response

Field	Type	Description
data	TwapOrderResponse	Response data when code is 0. See TwapOrderResponse in Schema

Replace multiple orders

POST ${SPOT_ENDPOINT}/trade/orders/replace

Replace/modify existing orders atomically.

• Auth: signed write

curl -X POST ${SPOT_ENDPOINT}/trade/orders/replace \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <ReplaceOrderRequest>

Request Body

Find ReplaceOrderRequest and ReplaceParams in Schema

Additional Information:

• Basic Validation

  • The batch cannot be empty.

  • The length of batch should less than or equals to 100.

  • Only limit GTC and limit GTX can be replaced.

  • Only order with status NEW and PARTIALLY_FILLED can be replaced.

  • Either replace.origOrderID or replace.origClOrdID should be provided, but not both.

  • At least one of replace.price and replace.quantity should be provided.

• Price filter

  • The decimal precision of replacement price should not exceed symbol.pricePrecision, if provided. That is replace.price % 10^{-symbol.pricePrecision} = 0.

  • The replacement price must be multiple of symbol.tickSize. That is replace.price % symbol.tickSize = 0.

  • If symbol.minPrice is not 0, the replacement price should greater than or equals to symbol.minPrice.

  • If symbol.maxPrice is not 0, the replacement price should less than or equals to symbol.maxPrice.

  • The replacement will be rejected if price filter check failed.

• Lot size filter

  • The decimal precision of replacement quantity should not exceed symbol.quantityPrecision. That is replace.quantity % 10^{-symbol.quantityPrecision} = 0.

  • The replacement quantity must be multiple of symbol.stepSize. That is replace.quantity % symbol.stepSize = 0.

  • If symbol.minQuantity is not 0, the replacement quantity should greater than or equals to symbol.minQuantity.

  • If symbol.maxQuantity is not 0, the replacement quantity should less than or equals to symbol.maxQuantity.

  • The replacement will be rejected if lot size filter check failed.

• Notional filter

  • The gateway skips this filter for vault and liquidator accounts.

  • The replacement notional is replace.price * replace.quantity. If replace.price not provided, order.price is used. If replace.quantity not provided, order.quantity is used.

  • If symbol.minNotional is not 0, the replacement notional should greater than or equals to symbol.minNotional.

  • If symbol.maxNotional is not 0, the replacement notional should less than or equals to symbol.maxNotional.

  • The replacement will be rejected if notional filter check failed.

Response

Field	Type	Description
data	Array<ResponseData>	Response data when code is 0.

• ResponseData

  Name	Type	Required	Description
  code	int32	true	Response status code, 0 for success and other code for failure.
  clOrdID	string	true	Client order id; same as clOrdID in ReplaceParams.
  error	string	false	Error description for individual order. Only provided when code is not 0.
  orderID	uint64	false	Order id of the replaced order. Only provided when the code is 0.

The length of the response result array is usually the same as the length of batched request.

Important: Some errors are a deterministic function of the payload itself, and these are instead returned earlier as part of pre-validation. In this case, only one error is returned for the entire payload, as some of these errors do not apply to a specific order.

For API users that use batching, it's recommended to handle the case where a single error is returned for a batch of multiple orders. In this case, the response could be duplicated n times before being sent to the callback function, as the whole batch was rejected for this same reason.

Schedule cancel orders

POST ${SPOT_ENDPOINT}/trade/orders/schedule-cancel

Schedule a cancel-all operation at a future time. Omitting the time clears the scheduled cancel.

• Auth: signed write

curl -X POST ${SPOT_ENDPOINT}/trade/orders/schedule-cancel \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json' \
  -H 'X-API-Key: <API-Key>' \
  -H 'X-API-Sign: <API-Sign>' \
  -H 'X-API-Nonce: <API-Nonce>' \
  -d <ScheduleCancelRequest>

Request Body

See ScheduleCancelRequest in Schema

Name	Type	Required	Description
accountID	uint64	true	Account identifier.
scheduledTimestamp	uint64	false	Unix timestamp in milliseconds when the cancel-all should be triggered.

Additional Information:

• The scheduled time must be at least 5 seconds after the current time.

• When triggered, all open orders are canceled and a trigger count increments (max 10 per day, resets at 00:00 UTC).

• Omitting scheduledTimestamp removes the scheduled cancel.

Response

• No endpoint-specific data payload.