runtime

check_witness(hash_or_pubkey: Union[UInt160, ECPoint]) → bool

Verifies that the transactions or block of the calling contract has validated the required script hash.

>>> check_witness(calling_script_hash)
True

>>> check_witness(UInt160(bytes(20)))
False

Parameters:: hash_or_pubkey (UInt160 or ECPoint) – script hash or public key to validate
Returns:: a boolean value that represents whether the script hash was verified
Return type:: bool

notify(state: Any, notification_name: Optional[str] = None)

Notifies the client from the executing smart contract.

>>> var = 10
... notify(var)     # An event will be triggered
None

>>> var = 10
... notify(var, 'custom event name')     # An event will be triggered
None

Parameters:

state (Any) – the notification message
notification_name (str) – name that’ll be linked to the notification

log(message: str)

Show log messages to the client from the executing smart contract.

>>> log('log sent')     # An event that can be shown on the CLI
log sent

Parameters:: message (str) – the log message

get_trigger() → TriggerType

Return the smart contract trigger type.

>>> get_trigger()
TriggerType.APPLICATION

Returns:: a value that represents the contract trigger type
Return type:: TriggerType

get_notifications(script_hash: UInt160 = b'') → List[Notification]

This method gets current invocation notifications from specific ‘script_hash’.

>>> notify(1); notify(2); notify(3)
... get_notifications(UInt160(b'\xcfv\xe2\x8b\xd0\x06,JG\x8e\xe3Ua\x01\x13\x19\xf3\xcf\xa4\xd2'))
[
    [
        b'8\xfe\x11\n\xff7J\xb8}\xe9x6@\xea\x0b\x00\xf1|\x82v',
        'notify',
        [1]
    ],
    [
        b'8\xfe\x11\n\xff7J\xb8}\xe9x6@\xea\x0b\x00\xf1|\x82v',
        'notify',
        [2]
    ],
    [
        b'8\xfe\x11\n\xff7J\xb8}\xe9x6@\xea\x0b\x00\xf1|\x82v',
        'notify',
        [3]
    ]
]

Parameters:: script_hash (UInt160) – must have 20 bytes, but if it’s all zero 0000…0000 it refers to all existing notifications (like a * wildcard)
Returns:: It will return an array of all matched notifications
Return type:: List[Notification]

get_network() → int

Gets the magic number of the current network.

>>> get_network()
860243278

Returns:: the magic number of the current network
Return type:: int

burn_gas(gas: int)

Burns GAS to benefit the NEO ecosystem.

>>> burn_gas(1000)
None

Parameters:: gas (int) – the amount of GAS that will be burned
Raises:: Exception – raised if gas value is negative.

get_random() → int

Gets the next random number.

>>> get_random()
191320526825634396960813166838892720709

>>> get_random()
99083669484001682562631729023191545809

>>> get_random()
328056213623902365838800581788496514419

Returns:: the next random number
Return type:: int

load_script(script: bytes, args: Sequence = (), flags: CallFlags = CallFlags.NONE) → Any

Loads a script at runtime.

>>> from typing import cast
... from boa3.builtin.vm import Opcode
... cast(int, load_script(Opcode.ADD, [10, 2]))
12

address_version: int

Gets the address version of the current network.

>>> address_version
53

executing_script_hash: UInt160

Gets the script hash of the current context.

>>> executing_script_hash
b'^b]\x90#\xbf\xcc\x1f\xd8\x9e\xe3\xa4zd\x14\xa4\xf0\x96\x9f`'

calling_script_hash: UInt160

Gets the script hash of the calling contract.

>>> calling_script_hash
b'\x05\x7f\xc2\x9d\xba\xb2\xc1x\xf5\x81\x83\xbf\xcb\x87/\xc3!\xca\xe1\xd0'

time: int

Gets the timestamp of the current block.

>>> time
1685395697108

gas_left: int

Gets the remaining GAS that can be spent in order to complete the execution.

>>> gas_left
1999015490

platform: str

Gets the name of the current platform.

>>> platform
'NEO'

invocation_counter: int

Gets the number of times the current contract has been called during the execution.

>>> invocation_counter
1

entry_script_hash: UInt160

Gets the script hash of the entry context.

>>> entry_script_hash
b'\tK\xb31\xa8\x13\x80`\xad\xf6\xda\xdf\xc6R\x9b\xfdB\xbf\x83\x8f'

script_container: Any

Gets the current script container.

>>> script_container
[
    b'\xf1y\xc2\xd6\x1c\xb6\x98\xa4\xdc\xf3\xd67s\xd7E\xf0<;\x98+\xa2T\x03P,T\xe8\xc6{ \x101', 
    0, 
    442907905, 
    '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00', 
    0, 
    0, 
    0, 
    ''
]

>>> script_container
[
    b"S{\xed'\x85&\xf5\x93U=\xc1\xbf'\x95\xc4/\x80X\xdb\xd5\xa1-\x97q\x85\xe3I\xe5\x99cd\x04",
    0,
    '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
    '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
    1468595301000,
    2083236893,
    0,
    0,
    b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
    0,
]

Subpackages

class Notification

Bases: object

Represents a notification.

Variables:

script_hash (UInt160) – the script hash of the notification sender
event_name (str) – the notification’s name
state (tuple) – a tuple value storing all the notification contents.

class TriggerType(value)

Bases: IntFlag

Represents the triggers for running smart contracts. Triggers enable the contract to execute different logic under different usage scenarios.

Check out Neo’s Documentation to learn more about TriggerTypes.

ON_PERSIST

Indicate that the contract is triggered by the system to execute the OnPersist method of the native contracts.

POST_PERSIST

Indicate that the contract is triggered by the system to execute the PostPersist method of the native contracts.

SYSTEM

The combination of all system triggers.

VERIFICATION

Indicates that the contract is triggered by the verification of a IVerifiable.

APPLICATION

Indicates that the contract is triggered by the execution of transactions.

ALL

The combination of all triggers.