Order Encoding

An order signs token quantities, addresses and execution permissions. Its extension carries the rate inputs and callback targets; the signed salt binds those bytes. See the order contract reference for field meanings, pricing and lifecycle methods.

Signature domain

The four order address fields use the upstream Address wrapper: uint256 in calldata, with the address in the low 160 bits. MakerTraits and TakerTraits also encode as uint256. EIP-712 instead types the four address fields as address, in this exact order:

Order(uint256 salt,address maker,address receiver,address makerAsset,address takerAsset,uint256 makingAmount,uint256 takingAmount,uint256 makerTraits)

hashOrder returns the EIP-712 digest. DOMAIN_SEPARATOR returns the domain separator. A different chain or settlement produces a different digest. EOA fill signatures use compact EIP-2098 r and vs; contract fills pass ERC-1271 signature bytes to the maker.

Source: order type and hash, settlement domain.

Rate payload

The payload identifies the registered PT, derivative kind, quote kind and signed APY. It occupies the extension's customData tail. For YT orders, the PT still identifies the market; the getter resolves YT from that PT.

customData is exactly 36 packed bytes, with no ABI tuple padding:

function decodeRateOrderData(bytes calldata data)
    external pure returns (RateOrderDataV1 memory);

The decoder returns the fields above in that order, emits no events and reverts with InvalidRateData() for another length, version, enum, nonzero flags or zero PT. Market registration, maturity and APY bounds are checked during pricing.

Extension

An extension starts with a 32-byte offset header, followed by eight dynamic fields and then customData. The header stores cumulative end offsets relative to the first byte after the header. Empty fields repeat the previous offset.

For cumulative ends end[0]..end[7], encode:

offsets = sum(end[i] << (32 * i))
extension = bytes32(offsets) || field[0] || ... || field[7] || customData

customData starts at 32 + end[7]; it has no ninth offset. Set the maker's extension flag and bind the low 160 bits of salt to the low 160 bits of keccak256(extension). Missing, unexpected or hash-mismatched extensions fail settlement validation.

For pre/post-interactions, fields shorter than 20 bytes call the maker with the whole field as data; otherwise, the first 20 bytes select the target.

Source: extension fields, offset slicing, salt binding.

Public fee extension

A public fee order sends payment to SpectraRateFeeTaker, which splits it between maker and fee collector. Its receiver, both getters and post-interaction target must name that fee taker.

Append the 36-byte rate payload: total extension length is 32 + 60 + 36 = 128 bytes. No getter-local or post-interaction extra data is appended. Set the post-interaction flag and leave maker native unwrap clear. For a fee-free rate order, the rate getter likewise requires empty getter-local data, reverting with NonEmptyExtraData() otherwise.

Order-book admission profile

The order-book API accepts Spectra's canonical public fee-order profile, not arbitrary 1inch orders. Submit the generated order, including its extension and indexed terms, in the POST /create request.

Orders that fail this canonical validation are rejected with HTTP 422 and code: ORDER_VALIDATION_FAILED. Malformed request bodies return HTTP 400. Passing encoding checks does not bypass signature, funding or live-order admission checks.

The order contains no numeric fee field. It selects the configured fee-taker contract, which reads its live fee(). An alternate fee receiver, different getters or custom fee payloads fail canonical validation. Adding a fee property to the JSON request does not override the fee.

Maker traits

Maker traits are signed permissions. Partial and multiple fills must both be enabled to use remaining-amount storage and series epochs. Otherwise, settlement uses nonce-bit invalidation.

Other bits are unused. Series 0 groups the maker's orders across markets; advancing it leaves other series and orders without epoch checks unaffected. The caller restriction compares only low 80 address bits; an exact full-address allowlist requires a separate pre-interaction guard.

Upstream expiry fails only when a nonzero expiry is strictly earlier than the current timestamp. An expiry strictly before maturity is an order-construction policy; the rate getter independently rejects execution at maturity.

Source: maker traits.

Taker traits and fill arguments

Taker traits are supplied with each fill. They choose the amount mode, bound execution price and delimit packed fill arguments.

Other bits are unused. In maker-amount mode, the threshold is maximum payment for the requested maker quantity. In taking-amount mode, it is minimum maker quantity for the requested payment. Zero disables the threshold; clamped fills preserve the proportional price constraint.

For an Args fill entry point, concatenate:

args = [20-byte target, if bit 251 is set] || extension || interaction
interaction = [20-byte callback target] || callback data

Without the target flag, maker assets go to the immediate caller. Extension and interaction lengths come from their trait fields. No-Args methods supply neither extension nor interaction. The batch filler supplies its own target and lengths; see batch settlement.

Source: taker-trait masks, argument parsing.