Output

enum OutputType : uint8 {
    Coin = 0,
    Contract = 1,
    Change = 2,
    Variable = 3,
    ContractCreated = 4,
}

name	type	description
type	OutputType	Type of output.
data	One of OutputCoin, OutputContract, OutputChange, OutputVariable, or OutputContractCreated.	Output data.

Transaction is invalid if:

• type > OutputType.ContractCreated

OutputCoin

name	type	description
to	byte[32]	Receiving address or predicate root.
amount	uint64	Amount of coins to send.
asset_id	byte[32]	Asset ID of coins.

OutputContract

name	type	description
inputIndex	uint16	Index of input contract.
balanceRoot	byte[32]	Root of amount of coins owned by contract after transaction execution.
stateRoot	byte[32]	State root of contract after transaction execution.

Transaction is invalid if:

• inputIndex >= tx.inputsCount
• tx.inputs[inputIndex].type != InputType.Contract

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

Note: when verifying a predicate or executing a script, balanceRoot and stateRoot are initialized to zero.

The balance root balanceRoot is the root of the SMT of balance leaves. Each balance is a uint64, keyed by asset ID (a byte[32]).

The state root stateRoot is the root of the SMT of storage slots. Each storage slot is a byte[32], keyed by a byte[32].

OutputChange

name	type	description
to	byte[32]	Receiving address or predicate root.
amount	uint64	Amount of coins to send.
asset_id	byte[32]	Asset ID of coins.

Transaction is invalid if:

• any other output has type OutputType.OutputChange and asset ID asset_id (i.e. only one change output per asset ID is allowed)

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

Note: when verifying a predicate or executing a script, amount is initialized to zero.

This output type indicates that the output's amount may vary based on transaction execution, but is otherwise identical to a Coin output. An amount of zero after transaction execution indicates that the output is unspendable and can be pruned from the UTXO set.

OutputVariable

name	type	description
to	byte[32]	Receiving address or predicate root.
amount	uint64	Amount of coins to send.
asset_id	byte[32]	Asset ID of coins.

Note: when signing a transaction, to, amount, and asset_id are set to zero.

Note: when verifying a predicate or executing a script, to, amount, and asset_id are initialized to zero.

This output type indicates that the output's amount and owner may vary based on transaction execution, but is otherwise identical to a Coin output. An amount of zero after transaction execution indicates that the output is unspendable and can be pruned from the UTXO set.

OutputContractCreated

name	type	description
contractID	byte[32]	Contract ID.
stateRoot	byte[32]	Initial state root of contract.