Transaction object

The transaction object is the struct broadcasted to the p2p network, generated by local execution by the user's PXE. Sequencers pick up transactions from the p2p network to include in a block.

Transaction object struct

The fields of a transaction object are the following:

Field	Type	Description
data	PrivateKernelPublicInputsFinal	Public inputs (ie output) of the last iteration of the private kernel circuit for this transaction.
proof	Buffer	Zero-knowledge honk proof for the last iteration of the private kernel circuit for this transaction.
encryptedLogs	Buffer[][]	Encrypted logs emitted per function in this transaction. Position i contains the encrypted logs emitted by the i-th function execution.
unencryptedLogs	Buffer[][]	Equivalent to the above but for unencrypted logs.
enqueuedPublicFunctionCalls	PublicCallRequest[]	List of public function calls to run during public execution.

Private kernel public inputs final

Output of the last iteration of the private kernel circuit. Includes accumulated data after recursing through all private function calls, as well as constant data composed of block header reflecting the state of the chain when such functions were executed, and the global transaction context. Refer to the circuits section for more info.

Accumulated data

Field	Type	Description
newNoteHashes	Field[]	The new note hashes made in this transaction.
newNullifiers	Field[]	The new nullifiers made in this transaction.
nullifiedNoteHashes	Field[]	The note hashes which are nullified by a nullifier in the above list.
privateCallStack	Field[]	Current private call stack.
publicCallStack	Field[]	Current public call stack.
newL2ToL1Msgs	Field[]	All the new L2 to L1 messages created in this transaction.
encryptedLogsHash	Field[]	Accumulated encrypted logs hash from all the previous kernel iterations.
unencryptedLogsHash	Field[]	Accumulated unencrypted logs hash from all the previous kernel iterations.
encryptedLogPreimagesLength	Field	Total accumulated length of the encrypted log preimages emitted in all the previous kernel iterations.
unencryptedLogPreimagesLength	Field	Total accumulated length of the unencrypted log preimages emitted in all the previous kernel iterations.
maxBlockNum	Field	Maximum block number (inclusive) for inclusion of this transaction in a block.

Block header

Field	Type	Description
noteHashTreeRoot	Field	Root of the note hash tree at the time of when this information was assembled.
nullifierTreeRoot	Field	Root of the nullifier tree at the time of when this information was assembled.
contractTreeRoot	Field	Root of the contract tree at the time of when this information was assembled.
l1ToL2MessageTreeRoot	Field	Root of the L1 to L2 message tree at the time of when this information was assembled.
archiveRoot	Field	Root of the archive at the time of when this information was assembled.
privateKernelVkTreeRoot	Field	Root of the private kernel VK tree at the time of when this information was assembled (future enhancement).
publicDataTreeRoot	Field	Current public state tree hash.
globalVariablesHash	Field	Previous globals hash, this value is used to recalculate the block hash.

Public call request

Each public call request is the preimage of a public call stack item in the transaction's data, and has the following fields:

Field	Type	Description
contractAddress	AztecAddress	Address of the contract on which the function is invoked.
callContext	CallContext	Includes function selector and caller.
args	Field[]	Arguments to the function call.
sideEffectCounter	number?	Optional counter for ordering side effects of this function call.

Extended contract data

Each extended contract data corresponds to a contract being deployed by the transaction, and has the following fields:

Field	Type	Description
address	AztecAddress	Address where the contract is to be deployed.
portalAddress	EthereumAddress	Portal address on L1 for this contract (zero if none).
bytecode	Buffer	Encoded Brillig bytecode for all public functions in the contract.
publicKey	PublicKey	Master public encryption key for this contract (zero if none).
partialAddress	Field	Hash of the constructor arguments, salt, and bytecode.

Transaction hash

A transaction is identified by its transaction_hash. In order to be able to identify a transaction before it has been locally executed, the hash is computed from its transaction execution request by hashing:

• origin
• functionSelector
• argsHash
• txContent

The resulting transaction hash is always emitted during local execution as the first nullifier of the transaction, in order to prevent replay attacks. This is enforced by the private kernel circuit.