Limit order structure

Field	Type	Inner Solidity type	Description
salt	string	uint256	some unique value. It is necessary to be able to create limit orders with the same parameters (so that they have a different hash)
makerAsset	string	address	the address of the asset you want to sell (address of a token contract)
takerAsset	string	address	the address of the asset you want to buy (address of a token contract)
maker	string	address	the address of the limit order creator
receiver	string	address	by default contains a zero address, which means that taker asset will be sent to the address of the creator of the limit order. If you set a value, then taker asset will be sent to the specified address
allowedSender	string	address	by default contains a zero address, which means that a limit order is available for everyone to fill. If you set a value, then the limit order will be available for execution only for the specified address (private limit order)
makingAmount	string	uint256	amount of maker asset
takingAmount	string	uint256	amount of taker asset
interactions	string	bytes	hex bytes string with interactions meta fields concat(makerAssetData, takerAssetData, getMakingAmount, getTakingAmount, predicate, permit, preIntercation, postInteraction)
offsets	string	uint256	every 32's bytes represents offset of the n'ths interaction

interactions meta fields

Index	Field	Type	Inner Solidity type	Description
0	makerAssetData	string	bytes	the technical info about a maker asset and its amount
1	takerAssetData	string	bytes	the technical info about a taker asset and its amount
2	getMakingAmount	string	bytes	technical information to get the amount of the maker asset
3	getTakingAmount	string	bytes	technical information to get the amount of the taker asset
4	predicate	string	bytes	a predicate call data. See more Predicate docs
5	permit	string	bytes	a permit (EIP-2612) call data. Could be built using utility library
6	preInteraction	string	bytes	What to do before the transfer. A call data for InteractiveNotificationReceiver. See more Interaction receiver docs
7	postInteraction	string	bytes	What tot do after the transfer has been made. a call data for InteractiveNotificationReceiver. See more Interaction receiver docs

Example:

await new LimitOrderBuilder(...).buildLimitOrder({
    makerAssetAddress: '0x000000000000000000000000000000000000000A',
    takerAssetAddress: '0x000000000000000000000000000000000000000B',
    makerAddress: '0x0000000000000000000000000000000000000001',
    receiver: '0x0000000000000000000000000000000000000002',
    allowedSender: '0x0000000000000000000000000000000000000003',
    makingAmount: '100',
    takingAmount: '200',
    getMakingAmount: '0x11',
    getTakingAmount: '0x2222',
    predicate: '0x333333',
    permit: '0x44444444',
    preInteraction: '0x5555555555',
    postInteraction: '0x666666666666',
});

// {
//     salt: '390590399942',
//     makerAsset: '0x000000000000000000000000000000000000000A',
//     takerAsset: '0x000000000000000000000000000000000000000B',
//     maker: '0x0000000000000000000000000000000000000001',
//     receiver: '0x0000000000000000000000000000000000000002',
//     allowedSender: '0x0000000000000000000000000000000000000003',
//     makingAmount: '100',
//     takingAmount: '200',
//     offsets: '566158880104319961733422544660299808878295192710391671368140609028096',
//     interactions: '0x112222333333444444445555555555666666666666'
// }

Where the each offset is iteration bytes offset:

// interactions: '0x112222333333444444445555555555666666666666'
//                  ^ ^   ^     ^       ^         ^          ^
//                  1 2   4     7       11        16         21

// Note: offset is bytes offset. Not a hex offset.
// 
// > Buffer.from('112222333333444444445555555555666666666666', 'hex')
// <Buffer 11 22 22 33 33 33 44 44 44 44 55 55 55 55 55 66 66 66 66 66 66>
//         ^  ^     ^        ^           ^              ^              ^
//         1  2     4        7           11             16             21

(0n << (0n))                // makerAssetData, length: 0, start: 0, end:  0
    + (0n << (32n * 1n))    // takerAssetData, length: 0, start:  0, end: 0
    + (1n << (32n * 2n))    // getMakingAmount, length: 1, start: 0, end: 1
    + (3n << (32n * 3n))    // getTakingAmount, length: 2, start: 2, end: 3
    + (6n << (32n * 4n))    // predicate, length: 3, start: 4, end: 6
    + (10n << (32n * 5n))   // permit, length: 4, start: 7, end: 10
    + (15n << (32n * 6n))   // preInteraction, length: 5, start: 11, end: 15
    + (21n << (32n * 7n))   // postInteraction, length: 6, start: 16, end: 21
===
566158880104319961733422544660299808878295192710391671368140609028096
===
0x150000000f0000000a0000000600000003000000010000000000000000
// ^       ^       ^       ^       ^       ^       ^
// 21      15      10      6       3       1       0