The Offer ledger entry describes an Offer to exchange currencies in Xahau's decentralized exchange. (In finance, this is more traditionally known as an order.) An [OfferCreate transaction][] only creates an Offer entry in the ledger when the Offer cannot be fully executed immediately by consuming other Offers already in the ledger.
An Offer can become unfunded through other activities in the network while remaining in the ledger. When processing transactions, the network automatically prunes any unfunded Offers that those transactions come across. (Otherwise, unfunded Offers remain because only transactions can change the ledger state.)
An Offer object has the following fields:
Account
String
AccountID
Yes
The address of the account that owns this Offer.
BookDirectory
String
Hash256
Yes
The ID of the Offer Directory that links to this Offer.
BookNode
String
UInt64
Yes
A hint indicating which page of the offer directory links to this object, in case the directory consists of multiple pages.
Expiration
Number
UInt32
No
Indicates the time after which this Offer is considered unfunded. See [Specifying Time][] for details.
Flags
Number
UInt32
Yes
A bit-map of boolean flags enabled for this offer.
LedgerEntryType
String
UInt16
Yes
The value 0x006F, mapped to the string Offer, indicates that this object describes an Offer.
OwnerNode
String
UInt64
Yes
A hint indicating which page of the owner directory links to this object, in case the directory consists of multiple pages. Note: The offer does not contain a direct link to the owner directory containing it, since that value can be derived from the Account.
PreviousTxnID
String
Hash256
Yes
The identifying hash of the transaction that most recently modified this object.
PreviousTxnLgrSeq
Number
UInt32
Yes
The [index of the ledger][Ledger Index] that contains the transaction that most recently modified this object.
Sequence
Number
UInt32
Yes
The Sequence value of the [OfferCreate][] transaction that created this Offer object. Used in combination with the Account to identify this Offer.
TakerPays
String or Object
Amount
Yes
The remaining amount and type of currency requested by the Offer creator.
TakerGets
String or Object
Amount
Yes
The remaining amount and type of currency being provided by the Offer creator.
There are several options that can be either enabled or disabled when an [OfferCreate transaction][] creates an offer object. In the ledger, flags are represented as binary values that can be combined with bitwise-or operations. The bit values for the flags in the ledger are different than the values used to enable or disable those flags in a transaction. Ledger flags have names that begin with lsf.
Offer objects can have the following flag values:
Flag Name
Hex Value
Decimal Value
Corresponding OfferCreate Flag
Description
lsfPassive
0x00010000
65536
tfPassive
The object was placed as a passive Offer. This has no effect on the object in the ledger.
lsfSell
0x00020000
131072
tfSell
The object was placed as a sell Offer. This has no effect on the object in the ledger (because tfSell only matters if you get a better rate than you asked for, which cannot happen after the object enters the ledger).
The ID of an Offer object is the [SHA-512Half][] of the following values, concatenated in order:
The Offer space key (0x006F)
The AccountID of the account placing the Offer
The Sequence number of the [OfferCreate transaction][] that created the Offer.
If the OfferCreate transaction used a Ticket, use the TicketSequence value instead.