New Order

Type: TRADE · Weight: 1 · counted against the order buckets

Status: Implemented.

POST /api/v3/order

Place a LIMIT (good-till-cancelled) or MARKET (immediate-or-cancel) spot order. The response is an acknowledgement, not a fill report: executedQty is always 0 even when the order fills immediately. Read fills from myTrades and final state from allOrders.

Request — all parameters in the query string, signature last, empty body (see Request conventions)

POST /api/v3/order?symbol=CBTC-USDCB&side=BUY&type=LIMIT&quantity=0.001&price=50000&timestamp=1756600000000&signature=...

Parameters

Name	Type	Required	Notes
`symbol`	string	yes	e.g. `CBTC-USDCB`.
`side`	string	yes	`BUY` or `SELL`.
`type`	string	yes	`LIMIT` or `MARKET`.
`quantity`	string	yes	Base-asset quantity, a positive decimal. `stepSize` / `minQty` are not validated at order entry; round client-side.
`price`	string	LIMIT only	Limit price, a positive decimal (`tickSize` is not validated at order entry). Must be absent for `MARKET` (`-1100` otherwise).
`newClientOrderId`	string	no	Idempotency key; a random UUID is generated if omitted. Echoed as `clientOrderId`. A repeat with the same value within 15 minutes returns the original `orderId` instead of placing a new order.
`timestamp`, `recvWindow`, `signature`			See Authentication.

timeInForce, quoteOrderQty, icebergQty, stopPrice, newOrderRespType, selfTradePreventionMode are ignored.

Execution semantics

LIMIT rests as GTC. Spot is always 1x: a BUY locks price × quantity of the quote asset, a SELL locks quantity of the base asset, at order entry.
MARKET is IOC with a 5 % protective band: a BUY may take asks up to bestAsk × 1.05, a SELL may hit bids down to bestBid × 0.95; the unfilled remainder is cancelled. The band price is also the amount locked for a BUY. An empty opposite side is rejected with -2010 Market order rejected: no counterparty liquidity.
Self-trade prevention is always on: the matcher skips your own resting orders and continues to the next counterparty; the resting order is neither filled nor cancelled.
Wallet-funded accounts (see On-chain Settlement): price × quantity (for MARKET, band price × quantity) must be at least the symbol's minNotional (-1013); the account must have completed MemberAuth (-2012) and must not be frozen (-2010). These gates run before anything else is validated.

Response — 200 (values illustrative)

{
  "symbol": "CBTC-USDCB",
  "orderId": "019910a4-9f21-7b34-8c56-1d2e3f4a5b6c",
  "orderListId": -1,
  "clientOrderId": "mm-quote-1756600000-17",
  "transactTime": 1756600000123,
  "price": "50000",
  "origQty": "0.001",
  "executedQty": "0.00000000",
  "cummulativeQuoteQty": "0.00000000",
  "status": "NEW",
  "timeInForce": "GTC",
  "type": "LIMIT",
  "side": "BUY"
}

Field	Notes
`orderId`	UUID string. Use it for `GET` / `DELETE /api/v3/order`.
`orderListId`	Always `-1` (no OCO).
`clientOrderId`	Your `newClientOrderId`, or the generated UUID. Not stored for later lookup — see Query Order.
`price`	Echo of `price` for LIMIT; `"0"` for MARKET in this acknowledgement (`GET /api/v3/order` and `allOrders` report the band price as `price`).
`origQty`	Echo of `quantity`, unnormalized.
`executedQty`, `cummulativeQuoteQty`	Always `"0.00000000"` in this acknowledgement.
`status`	Always `"NEW"`.
`timeInForce`	`"GTC"` for LIMIT, `"IOC"` for MARKET.

Errors

HTTP	code	msg / cause
`400`	`-1100`	Bad `side` or `type`; `price` sent with MARKET; the trading service rejected a parameter (unknown symbol, non-numeric or non-positive `price` / `quantity`).
`400`	`-1102`	`symbol`, `quantity`, or (LIMIT) `price` missing or empty.
`400`	`-1013`	`Filter failure: NOTIONAL` — below `minNotional` (wallet-funded accounts).
`422`	`-2010`	Insufficient balance to lock (same `msg` when the market is inactive or order entry is paused by the risk gate); or MARKET with no liquidity; or account frozen. Distinguish by `msg`.
`422`	`-2012`	Wallet enrollment (MemberAuth) required.
`429`	`-1003`	Weight or order-count bucket exhausted.
`500`	`-1000`	Trading service unavailable.

Authentication errors (-1021, -1022, -2014, -2015) as in Error codes.

Differences from Binance

Only LIMIT/GTC and MARKET/IOC. No LIMIT_MAKER, stop orders, quoteOrderQty, or newOrderRespType=FULL (the response never carries fills).
orderId is a UUID string; clientOrderId is not queryable.
Parameters must be in the query string.