Transaction Common Fields

Every transaction has the same set of common fields, plus additional fields based on the transaction type. Field names are case-sensitive. The common fields for all transactions are:

Field	JSON Type	[Internal Type][]	Description
Account	String	AccountID	(Required) The unique address of the account that initiated the transaction.
TransactionType	String	UInt16	(Required) The type of transaction. Valid transaction types include: Payment, OfferCreate, TrustSet, and many others.
Fee	String	Amount	(Required; auto-fillable) Integer amount of XAH, in drops, to be destroyed as a cost for distributing this transaction to the network. Some transaction types have different minimum requirements. See [Transaction Cost][] for details.
Sequence	Number	UInt32	(Required; auto-fillable) The sequence number of the account sending the transaction. A transaction is only valid if the Sequence number is exactly 1 greater than the previous transaction from the same account. The special case 0 means the transaction is using a Ticket instead (Added by the [TicketBatch amendment][].).
AccountTxnID	String	Hash256	(Optional) Hash value identifying another transaction. If provided, this transaction is only valid if the sending account's previously-sent transaction matches the provided hash.
Flags	Number	UInt32	(Optional) Set of bit-flags for this transaction.
LastLedgerSequence	Number	UInt32	(Optional; strongly recommended) Highest ledger index this transaction can appear in. Specifying this field places a strict upper limit on how long the transaction can wait to be validated or rejected. See Reliable Transaction Submission for more details.
Memos	Array of Objects	Array	(Optional) Additional arbitrary information used to identify this transaction.
NetworkID	Number	UInt32	(Network-specific) The network ID of the chain this transaction is intended for. MUST BE OMITTED for Mainnet and some test networks. REQUIRED on chains whose network ID is 1025 or higher.
Signers	Array	Array	(Optional) Array of objects that represent a multi-signature which authorizes this transaction.
SourceTag	Number	UInt32	(Optional) Arbitrary integer used to identify the reason for this payment, or a sender on whose behalf this transaction is made. Conventionally, a refund should specify the initial payment's SourceTag as the refund payment's DestinationTag.
SigningPubKey	String	Blob	(Automatically added when signing) Hex representation of the public key that corresponds to the private key used to sign this transaction. If an empty string, indicates a multi-signature is present in the Signers field instead.
TicketSequence	Number	UInt32	(Optional) The sequence number of the ticket to use in place of a Sequence number. If this is provided, Sequence must be 0. Cannot be used with AccountTxnID.
TxnSignature	String	Blob	(Automatically added when signing) The signature that verifies this transaction as originating from the account it says it is from.
EmitDetails	Object	Object	Contains details about the emission. This includes the generation of the emission, the burden of the emission, the callback address, the hash of the hook that emitted the transaction, the nonce of the emission, and the ID of the parent transaction.
HookParameters	Array	Array	The hook parameters of the tx.

[Removed in: rippled 0.28.0][]: The PreviousTxnID field of transactions was replaced by the AccountTxnID field. This String / Hash256 field is present in some historical transactions. This is unrelated to the field also named PreviousTxnID in some ledger objects.

AccountTxnID

The AccountTxnID field lets you chain your transactions together, so that a current transaction is not valid unless the previous transaction sent from the same account has a specific [transaction hash][identifying hash].

Unlike the PreviousTxnID field, which tracks the last transaction to modify an account (regardless of sender), the AccountTxnID tracks the last transaction sent by an account. To use AccountTxnID, you must first enable the asfAccountTxnID flag, so that the ledger keeps track of the ID for the account's previous transaction. (PreviousTxnID, by comparison, is always tracked.)

One situation in which this is useful is if you have a primary system for submitting transactions and a passive backup system. If the passive backup system becomes disconnected from the primary, but the primary is not fully dead, and they both begin operating at the same time, you could potentially have serious problems like some transactions sending twice and others not at all. Chaining your transactions together with AccountTxnID ensures that, even if both systems are active, only one of them can submit valid transactions at a time.

The AccountTxnID field cannot be used on transactions that use Tickets. Transactions that use AccountTxnID cannot be placed in the transaction queue.

Auto-fillable Fields

Some fields can be automatically filled in before a transaction is signed, either by a xahaud server or by a client library. Auto-filling values requires an active connection to Xahau to get the latest state, so it cannot be done offline. The details can vary by library, but auto-filling always provides suitable values for at least the following fields:

• Fee - Automatically fill in the [Transaction Cost][] based on the network.

  Note: When using xahaud's [sign command][], you can limit the maximum possible auto-filled value, using the fee_mult_max and fee_mult_div parameters.)

• Sequence - Automatically use the next sequence number for the account sending the transaction.

For a production system, we recommend not leaving these fields to be filled by the server. For example, if transaction costs become high due to a temporary spike in network load, you may want to wait for the cost to decrease before sending some transactions, instead of paying the temporarily-high cost.

The Paths field of the [Payment transaction][] type can also be automatically filled in.

Flags Field

The Flags field can contain various options that affect how a transaction should behave. The options are represented as binary values that can be combined with bitwise-or operations to set multiple flags at once.

To check whether a transaction has a given flag enabled, use the bitwise-and operator on the flag's value and the Flags field. A result of zero indicates the flag is disabled, and a result equal to the flag value indicates the flag is enabled. (If you got any other result, you did something wrong.)

Most flags only have meaning for a specific transaction type. The same bitwise value may be reused for flags on different transaction types, so it is important to pay attention to the TransactionType field when setting and reading flags.

Bits that are not defined as flags MUST be 0. (The [fix1543 amendment][] enforces this rule on some transaction types. Most transaction types enforce this rule by default.)

Global Flags

The only flag that applies globally to all transactions is as follows:

Flag Name	Hex Value	Decimal Value	Description
tfFullyCanonicalSig	0x80000000	2147483648	DEPRECATED No effect. (If the [RequireFullyCanonicalSig amendment][] is not enabled, this flag enforces a fully-canonical signature.)

When using the [sign method][] (or [submit method][] in "sign-and-submit" mode), xahaud adds a Flags field with tfFullyCanonicalSig enabled unless the Flags field is already present. The tfFullyCanonicalSig flag is not automatically enabled if Flags is explicitly specified. The flag is not automatically enabled when using the [sign_for method][] to add a signature to a multi-signed transaction.

Note: The tfFullyCanonicalSig flag was used from 2014 until 2020 to protect against transaction malleability while maintaining compatibility with legacy signing software. The [RequireFullyCanonicalSig amendment][] ended compatibility with such legacy software and made the protections the default for all transactions. If you are using a parallel network that does not have RequireFullyCanonicalSig enabled, you should always enable the tfFullyCanonicalSig flag to protect against transaction malleability.

Flag Ranges

A transaction's Flags field can contain flags that apply at different levels or contexts. Flags for each context are limited to the following ranges:

Range Name	Bit Mask	Description
Universal Flags	0xff000000	Flags that apply equally to all transaction types.
Type-based Flags	0x00ff0000	Flags with different meanings depending on the transaction type that uses them.
Reserved Flags	0x0000ffff	Flags that are not currently defined. A transaction is only valid if these flags are disabled.

Note: The [AccountSet transaction][] type has its own non-bitwise flags, which serve a similar purpose to type-based flags. Ledger objects also have a Flags field with different bitwise flag definitions.

Memos Field

The Memos field includes arbitrary messaging data with the transaction. It is presented as an array of objects. Each object has only one field, Memo, which in turn contains another object with one or more of the following fields:

Field	Type	[Internal Type][]	Description
MemoData	String	Blob	Arbitrary hex value, conventionally containing the content of the memo.
MemoFormat	String	Blob	Hex value representing characters allowed in URLs. Conventionally containing information on how the memo is encoded, for example as a MIME type.
MemoType	String	Blob	Hex value representing characters allowed in URLs. Conventionally, a unique relation (according to RFC 5988) that defines the format of this memo.

The MemoType and MemoFormat fields should only consist of the following characters: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~:/?#[]@!$&'()*+,;=%

The Memos field is limited to no more than 1 KB in size (when serialized in binary format).

Example of a transaction with a Memos field:

{
    "TransactionType": "Payment",
    "Account": "rMmTCjGFRWPz8S2zAUUoNVSQHxtRQD4eCx",
    "Destination": "r3kmLJN5D28dHuH8vZNUZpMC43pEHpaocV",
    "Memos": [
        {
            "Memo": {
                "MemoType": "687474703a2f2f6578616d706c652e636f6d2f6d656d6f2f67656e65726963",
                "MemoData": "72656e74"
            }
        }
    ],
    "Amount": "1"
}

NetworkID Field

[New in: rippled 1.11.0][]

The NetworkID field is a protection against "cross-chain" transaction replay attacks, preventing the same transaction from being copied over and executing on a parallel network that it wasn't intended for. For compatibility with existing chains, the NetworkID field must be omitted on any network with a Network ID of 1024 or less, but must be included on any network with a Network ID of 1025 or greater. The following table shows the status and values for various known networks:

Network	ID	NetworkID Field
Mainnet	0	Disallowed
Testnet	1	Disallowed
Devnet	2	Disallowed
AMM Devnet	25	Disallowed
Sidechains Devnet Locking Chain	2551	Disallowed, but will become required after an update
Sidechains Devnet Issuing Chain	2552	Disallowed, but will become required after an update
Xahau Testnet	21338	Required
Xahau Mainnet	21337	Required

Transaction replay attacks are theoretically possible, but require specific conditions on the second network. All of the following must be true:

• The transaction's sender is a funded account on the second network.

• The sender's Sequence number on the second network matches the transaction's Sequence, or the transaction uses a Ticket that's available on the second network.

• Either the transaction does not have a LastLedgerSequence field, or it specifies a value that is higher than the current ledger index on the second ledger.

  • Mainnet generally has a higher ledger index than test networks or sidechains, so it is easier to replay Mainnet transactions on a sidechain or test network than the other way around, when transactions use LastLedgerSequence as intended.

• Either the networks both have IDs of 1024 or less, both networks use the same ID, or the second network does not require the NetworkID field.

Signers Field

The Signers field contains a multi-signature, which has signatures from up to 8 key pairs, that together should authorize the transaction. The Signers list is an array of objects, each with one field, Signer. The Signer field has the following nested fields:

Field	Type	[Internal Type][]	Description
Account	String	AccountID	The address associated with this signature, as it appears in the signer list.
TxnSignature	String	Blob	A signature for this transaction, verifiable using the SigningPubKey.
SigningPubKey	String	Blob	The public key used to create this signature.

The SigningPubKey must be a key that is associated with the Account address. If the referenced Account is a funded account in the ledger, then the SigningPubKey can be that account's current Regular Key if one is set. It could also be that account's Master Key, unless the lsfDisableMaster flag is enabled. If the referenced Account address is not a funded account in the ledger, then the SigningPubKey must be the master key associated with that address.

Because signature verification is a compute-intensive task, multi-signed transactions cost additional XAH to relay to the network. Each signature included in the multi-signature increases the [transaction cost][] required for the transaction. For example, if the current minimum transaction cost to relay a transaction to the network is 10000 drops, then a multi-signed transaction with 3 entries in the Signers array would need a Fee value of at least 40000 drops to relay.

EmitDetails Fields

An EmitDetails object has the following fields:

Field	JSON Type	[Internal Type][]	Required?	Description
EmitGeneration	Number	UInt32	Yes	This field keeps track of a chain of emitted transactions that in turn cause other transactions to be emitted.
EmitBurden	String	UInt64	Yes	This field is a heuristic for detecting forkbombs. Fees are based on burden and will increase exponentially when a chain reaction is started to prevent the network becoming overun by self-reinforcing emitted transactions.
EmitParentTxnID	String	Hash256	Yes	The Hook Execution that emitted the transaction is connected to the Originating Transaction. Therefore this field is always required for the efficient tracing of behaviour.
EmitNonce	String	Hash256	Yes	Emitted Transactions would be identical with the same fields and therefore have identical transaction hashes if a nonce were not used. However every node on the network needs to agree on the nonce, so a special Hook API to produce a deterministic nonce is made available.
EmitCallback	String	AccountID	No	This field is used by xahld when it needs to intitate a callback, such that it knows which Hook and account to initate the callback on. Callbacks happen when an emitted transaction is accepted into a ledger.
EmitHookHash	String	Hash256	Yes	The SHA512H of the Hook at the time it was executed.

Hook Parameters

The HookParameters field is an array of objects that specify the parameters of the hook. Each parameter object has the following fields:

Field	JSON Type	Internal Type	Description
Name	String	Blob	The name of the parameter.
Value	String	Blob	The value of the parameter.