Struct AuthTxFeeCollector 

pub struct AuthTxFeeCollector { /* private fields */ }

An AccountComponent implementing the authentication scheme of a TX_FEE collector account: an account that forwards the assets of the notes it consumes and is never changed by a transaction.

It exports the procedure auth_tx_fee_collector, which:

• Creates a P2ID note for the target given by the auth args (see Self::auth_args) and moves the single asset of every consumed note into it, straight from the note; the account’s vault is never touched. A transaction consuming no notes is rejected, except for the one creating the account, which then creates no P2ID note.
• Asserts the account’s commitment is the one it had at the start of the transaction.
• Never increments the nonce, except once when the account is created. That transaction is checked against the vault instead of the full commitment, so the account cannot be created holding assets.
• Verifies a signature over the transaction summary against the public key in storage, under the signature scheme stored alongside it.
• Creates no TX_FEE note.

The account is stateless after deployment, and transactions against it can be built concurrently. A batch builder collects the TX_FEE notes of many batches this way: each transaction consumes one batch’s fee notes and forwards their assets to the builder’s own account.

Replay protection comes from the input notes the signed transaction summary binds: a transaction leaving the account unchanged must consume at least one input note to be valid, and a note can be consumed once.

Like every auth component, it is installed alongside at least one other component, typically BasicWallet.

Implementations

impl AuthTxFeeCollector

pub const NAME: &'static str = "miden::standards::auth::tx_fee_collector"

The name of the component.

pub const fn name() -> AccountComponentName

Returns the canonical AccountComponentName of this component.

pub fn code() -> &'static AccountComponentCode

Returns the AccountComponentCode of this component.

pub fn new(approver: Approver) -> AuthTxFeeCollector

Creates a new AuthTxFeeCollector component with the given approver.

pub fn falcon512_poseidon2(pub_key: PublicKey<Variant>) -> AuthTxFeeCollector

Creates a new AuthTxFeeCollector component using the Falcon512Poseidon2 signature scheme.

The public key commitment is derived from the provided Falcon512 public key.

pub fn ecdsa_k256_keccak(pub_key: PublicKey) -> AuthTxFeeCollector

Creates a new AuthTxFeeCollector component using the EcdsaK256Keccak signature scheme.

The public key commitment is derived from the provided ECDSA K256 public key.

Privacy

This scheme discloses the signer’s public key and signature at proving time and therefore does not provide public-key privacy. See AuthScheme::EcdsaK256Keccak for details, and prefer falcon512_poseidon2 if signer-key privacy is required.

pub fn from_public_key(pub_key: PublicKey) -> AuthTxFeeCollector

Creates a new AuthTxFeeCollector component from a PublicKey.

The authentication scheme and public key commitment are derived from the provided key.

pub fn approver(&self) -> Approver

Returns the approver of this component.

pub fn auth_args(target: AccountId, note_type: NoteType) -> Word

Returns the auth args that make the auth procedure create its P2ID note for target.

The word is [target_id_suffix, target_id_prefix, tag, note_type], with the tag derived from target as by NoteTag::with_account_target. Pass it as the transaction’s auth args.

pub fn derive_serial_number( auth_args: Word, input_notes_commitment: Word, ) -> Word

Derives the serial number of the P2ID note the auth procedure creates in a transaction with the given auth args and input notes commitment.

The serial number is hash(auth_args || input_notes_commitment), which is unique per transaction since no two valid transactions consume the same notes. Together with the target it lets the note’s recipient be computed before the transaction executes.

This derivation must be kept in sync with forward_note_assets in the component’s MASM code.

pub fn public_key_slot() -> &'static StorageSlotName

Returns the StorageSlotName where the public key is stored.

pub fn signature_scheme_slot() -> &'static StorageSlotName

Returns the StorageSlotName where the signature scheme is stored.

pub fn public_key_slot_schema() -> (StorageSlotName, StorageSlotSchema)

Returns the storage slot schema for the public key slot.

pub fn signature_scheme_slot_schema() -> (StorageSlotName, StorageSlotSchema)

Returns the storage slot schema for the signature scheme slot.

pub fn component_metadata() -> AccountComponentMetadata

Returns the AccountComponentMetadata for this component.

Trait Implementations

impl From<AuthTxFeeCollector> for AccountComponent

fn from(collector: AuthTxFeeCollector) -> AccountComponent

Converts to this type from the input type.