Order Types

TL;DR

Darknyx has three native order types: limit, IOC, and FOK. A market order is a convention (an IOC with a price cap) and an all-or-none order is a limit with its minimum fill size set to the full amount. Every order clears at the batch's single oracle-anchored price.

How matching works here

Darknyx is a batch auction, not a continuous order book. Each tick, the engine collects the resting orders that cross and clears them at a single uniform price anchored to the market's oracle (see Clearing Price). There is no maker/taker ordering within a batch; both sides of every match get the same price. The order type controls how long an order is willing to wait and whether it may rest.

Native types

Limit

order_type: "limit"

A resting order with a worst-acceptable price_limit. It stays in the book across batches until it fills, reaches its expiry_slot, or you cancel it. It fills only at a clearing price at least as good as its limit. This is the default for providing liquidity.

• A bid limit fills at the clearing price if that price is <= price_limit.
• An ask limit fills if the clearing price is >= price_limit.

IOC: Immediate-or-Cancel

order_type: "ioc"

Takes whatever it can in the batch it arrives in, then cancels any remainder. It never rests. Use it to cross the spread now without leaving a resting order behind. A bid IOC names a price_limit as its worst price; an ask IOC may use 0 to accept any clearing price.

FOK: Fill-or-Kill

order_type: "fok"

All-or-nothing, immediately. It fills its entire size in its arrival batch or is dropped; it never rests and never partially fills. Use it when a partial execution is worse than none.

Conventions built on the native types

These are not separate wire types; they are well-known configurations of the native fields. The SDK exposes a builder for each so you do not hand-encode them.

Market

A market order is an IOC with a price cap:

• A market bid is an IOC whose price_limit is the worst price you will pay (your collateral note must cover it).
• A market ask is an IOC with price_limit = 0, selling into any clearing price.

Because it is IOC, the residual auto-cancels; a market order never rests and never pins a note in the book.

All-or-None (resting)

An all-or-none order is a limit with min_fill_size = amount. It rests like a normal limit but only fills if the batch can fill its entire size at its limit or better; otherwise it waits. Unlike FOK (which is immediate), an AON limit keeps resting until a batch can satisfy it whole. See Execution Attributes.

Summary

Type	Rests?	Partial fills?	Use it for
Limit	Yes	Yes	Providing liquidity at a price.
Limit + AON	Yes	No (all-or-none)	Resting liquidity you only want filled whole.
Market (IOC + cap)	No	Yes	Crossing now, up to a price cap.
IOC	No	Yes	Taking available liquidity, no resting remainder.
FOK	No	No (all-or-none)	Immediate, whole, or nothing.

See Order Compatibility for which combinations of type, time-in-force, and execution attributes are valid.