Fuel Specs

Icon LinkInput

enum InputType : uint8 {
    Coin = 0,
    Contract = 1,
    Message = 2,
}

name	type	description
`type`	InputType	Type of input.
`data`	One of InputCoin , InputContract , or InputMessage	Input data.

Transaction is invalid if:

type > InputType.Message

Icon LinkInputCoin

name	type	description
`txID`	`byte[32]`	Hash of transaction.
`outputIndex`	`uint8`	Index of transaction output.
`owner`	`byte[32]`	Owning address or predicate root.
`amount`	`uint64`	Amount of coins.
`asset_id`	`byte[32]`	Asset ID of the coins.
`txPointer`	TXPointer	Points to the TX whose output is being spent.
`witnessIndex`	`uint8`	Index of witness that authorizes spending the coin.
`maturity`	`uint32`	UTXO being spent must have been created at least this many blocks ago.
`predicateGasUsed`	`uint64`	Gas used by predicate.
`predicateLength`	`uint16`	Length of predicate, in instructions.
`predicateDataLength`	`uint16`	Length of predicate input data, in bytes.
`predicate`	`byte[]`	Predicate bytecode.
`predicateData`	`byte[]`	Predicate input data (parameters).

Given helper len() that returns the number of bytes of a field.

Transaction is invalid if:

witnessIndex >= tx.witnessesCount
predicateLength > MAX_PREDICATE_LENGTH
predicateDataLength > MAX_PREDICATE_DATA_LENGTH
If predicateLength > 0; the computed predicate root (see below) is not equal owner
predicateLength * 4 != len(predicate)
predicateDataLength != len(predicateData)
predicateGasUsed > MAX_GAS_PER_PREDICATE

If h is the block height the UTXO being spent was created, transaction is invalid if blockheight() < h + maturity.

Note: when signing a transaction, txPointer and predicateGasUsed is set to zero.

Note: when verifying and estimating a predicate, txPointer and predicateGasUsed is initialized to zero.

Note: when executing a script, txPointer is initialized to the TX whose output is being spent.

The predicate root is computed here .

Icon LinkInputContract

name	type	description
`txID`	`byte[32]`	Hash of transaction.
`outputIndex`	`uint8`	Index of transaction output.
`balanceRoot`	`byte[32]`	Root of amount of coins owned by contract before transaction execution.
`stateRoot`	`byte[32]`	State root of contract before transaction execution.
`txPointer`	TXPointer	Points to the TX whose output is being spent.
`contractID`	`byte[32]`	Contract ID.

Transaction is invalid if:

there is not exactly one output of type OutputType.Contract with inputIndex equal to this input's index

Note: when signing a transaction, txID, outputIndex, balanceRoot, stateRoot, and txPointer are set to zero.

Note: when verifying a predicate, txID, outputIndex, balanceRoot, stateRoot, and txPointer are initialized to zero.

Note: when executing a script, txID, outputIndex, balanceRoot, and stateRoot are initialized to the transaction ID, output index, amount, and state root of the contract with ID contractID, and txPointer is initialized to the TX whose output is being spent.

Icon LinkInputMessage

name	type	description
`sender`	`byte[32]`	The address of the message sender.
`recipient`	`byte[32]`	The address or predicate root of the message recipient.
`amount`	`uint64`	Amount of base asset coins sent with message.
`nonce`	`byte[32]`	The message nonce.
`witnessIndex`	`uint8`	Index of witness that authorizes spending the coin.
`predicateGasUsed`	`uint64`	Gas used by predicate execution.
`dataLength`	`uint16`	Length of message data, in bytes.
`predicateLength`	`uint16`	Length of predicate, in instructions.
`predicateDataLength`	`uint16`	Length of predicate input data, in bytes.
`data`	`byte[]`	The message data.
`predicate`	`byte[]`	Predicate bytecode.
`predicateData`	`byte[]`	Predicate input data (parameters).

Given helper len() that returns the number of bytes of a field.

Transaction is invalid if:

witnessIndex >= tx.witnessesCount
dataLength > MAX_MESSAGE_DATA_LENGTH
predicateLength > MAX_PREDICATE_LENGTH
predicateDataLength > MAX_PREDICATE_DATA_LENGTH
If predicateLength > 0; the computed predicate root (see below) is not equal recipient
dataLength != len(data)
predicateLength * 4 != len(predicate)
predicateDataLength != len(predicateData)
predicateGasUsed > MAX_GAS_PER_PREDICATE

The predicate root is computed here .

Note: InputMessages with data length greater than zero are not considered spent until they are included in a transaction of type TransactionType.Script with a ScriptResult receipt where result is equal to 0 indicating a successful script exit

Note: when signing a transaction, predicateGasUsed is set to zero.

Note: when verifying and estimating a predicate, predicateGasUsed is initialized to zero.

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