Skip to main content
The only real choice a maker makes is whether their price is allowed to move.

Fixed

Stores a ratio. Band-checked once, at creation, then never consults the oracle again. Predictable, and it keeps trading through a feed outage.

Pegged

Stores no price. Every fill is priced off Orakl’s five-minute reference and discounted so the taker’s realised edge lands exactly on the premium. Tracks the market instead of going stale.

​
Fixed — createOrder

1

Pair and size

buyToken must be the counter-token. sellAmount ≥ minOrderAmount[sellToken].
2

Expiry

expiry > block.timestamp and expiry ≤ now + maxOrderDuration.
3

Oracle read — strict

Reverts on a missing, non-positive or stale five-minute average. During a feed outage no new orders can be posted, of either kind.
4

Price band

Checked once. The band never applies again, so an order filled much later can sit far from the market — that is deliberate, not an oversight.
5

Escrow and record

safeTransferFrom(maker → this, sellAmount), the fee rate is snapshotted, an id is assigned and the order is added to both index sets.
buyAmount is the total the maker receives on a complete fill. Every partial fill uses that same ratio.

​
Pegged — createPeggedOrder

1

Premium

premiumBps ≤ maxPremiumBps ≤ MAX_PREMIUM_BPS (1000). A later configuration change does not alter orders already on the book.
2

A floor is mandatory

minRate == 0 is refused outright, so “no protection” can never be the quiet default that happens when a field is left alone.
3

The floor must be fillable at creation

minRate ≤ peggedRateNow(...), else FloorAboveMarket — otherwise a maker could post an order that passes creation and can never fill.
4

Escrow and record

As Fixed. buyAmount is stored as 0, because there is no price to store.

​
What the floor bounds, and why it matters

It bounds the money that changes hands, not the oracle answer. That is deliberate: if a newly selected feed uses different decimals, priceScale changes with it. Checking the settled amount keeps the maker’s floor expressed against the actual transfer value.
Below its floor a pegged order pauses itself and resumes on its own when the price recovers. Escrow is untouched, and protocol pause/oracle state never disables cancellation. A refund can still fail if the sell-token contract itself rejects the transfer; see the security model.

​
The Order struct

The first five fields share a single 32-byte slot. minRate lives inside the struct, which lives inside a mapping, so adding it consumed no contract storage slot.