Order Types

The eight order types, the four time-in-force policies, and which fields each one requires.

OrderRequest is the body of every order-placing operation — POST /orders, POST /orders/batch (as array elements) and POST /orders/preview, plus their /api/v1 twins.

This page is the cross-operation context the generated endpoint pages deliberately do not carry. Those pages state what the contract declares for one operation; the requirement matrix below is what you need to construct a valid order at all, and it is identical across all of them.

For the trader-facing view of what each type is for, see Order Types in the Exchange section.

Order placement schema

OrderRequest is the body of POST /orders, POST /orders/batch (as array elements), and POST /orders/preview, plus their /api/v1 twins.

It supports plain Limit and Market orders and six conditional order types (StopLimit, StopMarket, TakeProfitLimit, TakeProfitMarket, TrailingStop, TrailingLimit). Field requirements depend on order_type:

• Limit-family (Limit, StopLimit, TakeProfitLimit) require a limit price.
• Triggerable, non-trailing orders (StopLimit, StopMarket, TakeProfitLimit, TakeProfitMarket) require a trigger_price (the legacy stop_price field is accepted as a fallback when trigger_price is absent).
• TrailingStop is market-only — it fires as a market order — and requires trailing_offset_bps. It does not take a limit price or a trigger_price (the trigger anchor is derived from the mark price and the offset).
• TrailingLimit trails like TrailingStop but fires a limit order instead of a market order. It requires both trailing_offset_bps (the trailing trigger) and limit_offset_bps (the fire-time limit offset). It does not take price, trigger_price, or stop_price; the limit price is computed at fire time from the mark that crossed the offset.

Required fields by order type

market_id, side, order_type, quantity, and time_in_force are required for every order type. The four conditional fields resolve as follows:

order_type	price	trigger_price	trailing_offset_bps	limit_offset_bps	Fires as
Limit	Required	Not used	Ignored	Ignored	— (rests immediately)
Market	Omit	Not used	Ignored	Ignored	— (executes immediately)
StopLimit	Required	Required	Ignored	Ignored	Limit
StopMarket	Omit	Required	Ignored	Ignored	Market
TakeProfitLimit	Required	Required	Ignored	Ignored	Limit
TakeProfitMarket	Omit	Required	Ignored	Ignored	Market
TrailingStop	Not taken	Not taken	Required	Ignored	Market
TrailingLimit	Not taken	Not taken	Required	Required	Limit

Reading the matrix:

• Required — the request is rejected without it.
• Omit — the field is not part of a market-family order; there is no limit price to set.
• Not used / Not taken — the contract states the field is not used by this order type; the trailing types derive their trigger from the mark price and the offset instead.
• Ignored — the field may be present but has no effect for this order type.

The four triggerable, non-trailing types differ only in trigger direction: StopLimit and StopMarket fire when the mark price crosses trigger_price in the adverse direction; TakeProfitLimit and TakeProfitMarket fire on the favorable direction.

stop_price is deprecated

stop_price is deprecated in favour of trigger_price. The rules are exact:

• trigger_price is the canonical trigger threshold.
• stop_price is accepted only as a fallback, when trigger_price is absent.
• When both are supplied, trigger_price wins and stop_price is disregarded.
• Both are ignored entirely for Limit, Market, TrailingStop, and TrailingLimit orders.

New integrations should send trigger_price and never stop_price.

Time in force

time_in_force is required on every order and takes one of four policies:

Value	Meaning
GTC	Good-till-cancelled — rests on the book until filled or cancelled.
IOC	Immediate-or-cancel — fills what it can immediately, cancels the remainder.
FOK	Fill-or-kill — fills in full immediately or is cancelled entirely.
PostOnly	Rejects the order if it would take liquidity (cross the book) on entry, guaranteeing it rests as a maker.

PostOnly is the only value the contract describes in detail; the description above for GTC, IOC, and FOK states the standard meaning of each acronym, which the contract itself does not spell out.

OrderRequest fields

Field	Type	Required	Description
market_id	string	Yes	Market identifier, e.g. BTC-USDX-PERP.
side	Buy / Sell	Yes	Order side.
order_type	Limit / Market / StopLimit / StopMarket / TakeProfitLimit / TakeProfitMarket / TrailingStop / TrailingLimit	Yes	Order type. Limit and Market are unconditional. The remaining six are conditional: StopLimit / StopMarket fire when the mark price crosses trigger_price in the adverse direction; TakeProfitLimit / TakeProfitMarket fire on the favorable direction; TrailingStop fires as a market order when the mark retraces from its best-seen extreme by trailing_offset_bps; TrailingLimit fires the same way but rests a limit order priced off the fire price by limit_offset_bps.
price	decimal string	Conditional	Limit price. Required for limit-family orders (Limit, StopLimit, TakeProfitLimit); omit for market-family and trailing orders.
quantity	decimal string	Yes	Order size. Arbitrary-precision decimal serialized as a string (lossless) — parse with a decimal type, never a float.
time_in_force	GTC / IOC / FOK / PostOnly	Yes	Time-in-force policy. PostOnly rejects the order if it would take liquidity (cross the book) on entry, guaranteeing it rests as a maker.
reduce_only	boolean	No	The contract declares the field with no description; see Open questions.
stop_price	decimal string or null	No — deprecated	Deprecated — use trigger_price instead. Legacy trigger threshold for the stop / take-profit family. Accepted as a fallback only when trigger_price is absent; when both are supplied, trigger_price wins. Ignored for Limit, Market, TrailingStop, and TrailingLimit orders.
trigger_price	decimal string or null	Conditional	Canonical trigger threshold for triggerable, non-trailing orders (StopLimit, StopMarket, TakeProfitLimit, TakeProfitMarket), which require it (the legacy stop_price field is accepted as a fallback when this is omitted). Not used by Limit, Market, TrailingStop, or TrailingLimit orders.
trailing_offset_bps	integer (minimum 0) or null	Conditional	Trailing offset in basis points (1 bp = 0.01%). Required for TrailingStop and TrailingLimit orders; ignored for all other order types. The trailing trigger fires once the mark price retraces from its best-seen extreme by this many basis points: TrailingStop fires a market order, TrailingLimit fires a limit order priced by limit_offset_bps. A value of 0 is accepted and fires the trigger at the first mark-price evaluation after placement (no retracement required).
limit_offset_bps	integer (0–9999) or null	Conditional	Offset in basis points for the fired limit price (TrailingLimit only; required together with trailing_offset_bps). When the trailing trigger fires at fire_price, the injected limit order rests at fire_price × (1 + offset) for buys / × (1 − offset) for sells, tick-rounded toward the tighter bound. A value of 0 rests the limit exactly at fire_price. Ignored for other order types.

Order admission is governed by the margin inequality

Order admission is not a free-form validation: an order is accepted only if the account still satisfies the initial-margin requirement once the order's own reservation is included. That is the order-admission inequality (M.13) in the Exchange's margin model — see Margin math.

A 400 on POST /orders with an insufficient-margin reason is that inequality failing. Use POST /orders/preview to evaluate it without submitting.