blockchain

get_contract(hash: UInt160) → boa3.builtin.interop.contract.contract.Contract | None

Gets a contract with a given hash. If the script hash is not associated with a smart contract, then it will return None.

>>> get_contract(UInt160(b'\xcfv\xe2\x8b\xd0\x06,JG\x8e\xe3Ua\x01\x13\x19\xf3\xcf\xa4\xd2'))    # GAS script hash
{
    'id': -6,
    'update_counter': 0,
    'hash': b'\xcfv\xe2\x8b\xd0\x06,JG\x8e\xe3Ua\x01\x13\x19\xf3\xcf\xa4\xd2',
    'nef': b'NEF3neo-core-v3.0\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#\x10A\x1a\xf7{g@\x10A\x1a\xf7{g@\x10A\x1a\xf7{g@\x10A\x1a\xf7{g@\x10A\x1a\xf7{g@QA\xc7\x9e',
    'manifest': {
        'name': 'GasToken',
        'group': [],
        'supported_standards': ['NEP-17'],
        'abi': [[['balanceOf', [['account', 20]], 17, 0, True], ['decimals', [], 17, 7, True], ['symbol', [], 19, 14, True], ['totalSupply', [], 17, 21, True], ['transfer', [['from', 20], ['to', 20], ['amount', 17], ['data', 0]], 16, 28, False]], [['Transfer', [['from', 20], ['to', 20], ['amount', 17]]]]],
        'permissions': [[None, None]],
        'trusts': [],
        'extras': 'null'
    },
}

>>> get_contract(UInt160(bytes(20)))    # there is no smart contract associated with this script hash
None

Parameters:: hash (UInt160) – a smart contract hash
Returns:: a contract
Return type:: Contract
Raises:: Exception – raised if hash length isn’t 20 bytes.

get_block(index_or_hash: int | boa3.builtin.type.UInt256) → boa3.builtin.interop.blockchain.block.Block | None

Gets the block with the given index or hash. Will return None if the index or hash is not associated with a Block.

>>> get_block(0)        # first block
{
    'hash': b"S{\xed'\x85&\xf5\x93U=\xc1\xbf'\x95\xc4/\x80X\xdb\xd5\xa1-\x97q\x85\xe3I\xe5\x99cd\x04",
    'version': 0,
    'previous_hash': '\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',
    'merkle_root': '\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',
    'timestamp': 1468595301000,
    'nonce': 2083236893,
    'index': 0,
    'primary_index': 0,
    'next_consensus': b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
    'transaction_count': 0,
}

>>> get_block(UInt256(b"S{\xed'\x85&\xf5\x93U=\xc1\xbf'\x95\xc4/\x80X\xdb\xd5\xa1-\x97q\x85\xe3I\xe5\x99cd\x04"))        # first block
{
    'hash': b"S{\xed'\x85&\xf5\x93U=\xc1\xbf'\x95\xc4/\x80X\xdb\xd5\xa1-\x97q\x85\xe3I\xe5\x99cd\x04",
    'version': 0,
    'previous_hash': '\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',
    'merkle_root': '\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',
    'timestamp': 1468595301000,
    'nonce': 2083236893,
    'index': 0,
    'primary_index': 0,
    'next_consensus': b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
    'transaction_count': 0,
}

>>> get_block(9999999)      # block doesn't exist
None

>>> get_block(UInt256(bytes(32)))   # block doesn't exist
None

Parameters:: index_or_hash (int or UInt256) – index or hash identifier of the block
Returns:: the desired block, if exists. None otherwise
Return type:: Block or None

get_transaction(hash_: UInt256) → boa3.builtin.interop.blockchain.transaction.Transaction | None

Gets a transaction with the given hash. Will return None if the hash is not associated with a Transaction.

>>> get_transaction(UInt256(b'\xff\x7f\x18\x99\x8c\x1d\x10X{bA\xc2\xe3\xdf\xc8\xb0\x9f>\xd0\xd2G\xe3\xba\xd8\x96\xb9\x0e\xc1iS\xcdr'))
{
    'hash': b'\xff\x7f\x18\x99\x8c\x1d\x10X{bA\xc2\xe3\xdf\xc8\xb0\x9f>\xd0\xd2G\xe3\xba\xd8\x96\xb9\x0e\xc1iS\xcdr',
    'version': 0,
    'nonce': 2025056010,
    'sender': b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
    'system_fee': 2028330,
    'network_fee': 1206580,
    'valid_until_block': 5761,
    'script': b'\x0c\x14\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04\x11\xc0\x1f\x0c\tbalanceOf\x0c\x14\xcfv\xe2\x8b\xd0\x06,JG\x8e\xe3Ua\x01\x13\x19\xf3\xcf\xa4\xd2Ab}[R',
}

>>> get_transaction(UInt256(bytes(32)))   # transaction doesn't exist
None

Parameters:: hash (UInt256) – hash identifier of the transaction
Returns:: the Transaction, if exists. None otherwise

get_transaction_from_block(block_hash_or_height: boa3.builtin.type.UInt256 | int, tx_index: int) → boa3.builtin.interop.blockchain.transaction.Transaction | None

Gets a transaction from a block. Will return None if the block hash or height is not associated with a Transaction.

>>> get_transaction_from_block(1, 0)
{
    'hash': b'\xff\x7f\x18\x99\x8c\x1d\x10X{bA\xc2\xe3\xdf\xc8\xb0\x9f>\xd0\xd2G\xe3\xba\xd8\x96\xb9\x0e\xc1iS\xcdr',
    'version': 0,
    'nonce': 2025056010,
    'sender': b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
    'system_fee': 2028330,
    'network_fee': 1206580,
    'valid_until_block': 5761,
    'script': b'\x0c\x14\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04\x11\xc0\x1f\x0c\tbalanceOf\x0c\x14\xcfv\xe2\x8b\xd0\x06,JG\x8e\xe3Ua\x01\x13\x19\xf3\xcf\xa4\xd2Ab}[R',
}

>>> get_transaction_from_block(UInt256(b'\x29\x41\x06\xdb\x4c\xf3\x84\xa7\x20\x4d\xba\x0a\x04\x03\x72\xb3\x27\x76\xf2\x6e\xd3\x87\x49\x88\xd0\x3e\xff\x5d\xa9\x93\x8c\xa3'), 0)
{
    'hash': b'\xff\x7f\x18\x99\x8c\x1d\x10X{bA\xc2\xe3\xdf\xc8\xb0\x9f>\xd0\xd2G\xe3\xba\xd8\x96\xb9\x0e\xc1iS\xcdr',
    'version': 0,
    'nonce': 2025056010,
    'sender': b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
    'system_fee': 2028330,
    'network_fee': 1206580,
    'valid_until_block': 5761,
    'script': b'\x0c\x14\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04\x11\xc0\x1f\x0c\tbalanceOf\x0c\x14\xcfv\xe2\x8b\xd0\x06,JG\x8e\xe3Ua\x01\x13\x19\xf3\xcf\xa4\xd2Ab}[R',
}

>>> get_transaction_from_block(123456789, 0)     # height does not exist yet
None

>>> get_transaction_from_block(UInt256(bytes(32)), 0)     # block hash does not exist
None

Parameters:

block_hash_or_height (UInt256 or int) – a block identifier
tx_index (int) – the transaction identifier in the block

Returns:

the Transaction, if exists. None otherwise

get_transaction_height(hash_: UInt256) → int

Gets the height of a transaction. Will return -1 if the hash is not associated with a Transaction.

>>> get_transaction_height(UInt256(b'\x28\x89\x4f\xb6\x10\x62\x9d\xea\x4c\xcd\x00\x2e\x9e\x11\xa6\xd0\x3d\x28\x90\xc0\xe5\xd4\xfc\x8f\xc6\x4f\xcc\x32\x53\xb5\x48\x01'))
2108703

>>> get_transaction_height(UInt256(b'\x29\x41\x06\xdb\x4c\xf3\x84\xa7\x20\x4d\xba\x0a\x04\x03\x72\xb3\x27\x76\xf2\x6e\xd3\x87\x49\x88\xd0\x3e\xff\x5d\xa9\x93\x8c\xa3'))
10

>>> get_transaction_height(UInt256(bytes(32)))   # transaction doesn't exist
-1

Parameters:: hash (UInt256) – hash identifier of the transaction
Returns:: height of the transaction

get_transaction_signers(hash_: UInt256) → list[boa3.builtin.interop.blockchain.signer.Signer]

Gets a list with the signers of a transaction.

>>> get_transaction_signers(UInt256(b'\x29\x41\x06\xdb\x4c\xf3\x84\xa7\x20\x4d\xba\x0a\x04\x03\x72\xb3\x27\x76\xf2\x6e\xd3\x87\x49\x88\xd0\x3e\xff\x5d\xa9\x93\x8c\xa3'))
[
    {
        "account": b'\xa6\xea\xb0\xae\xaf\xb4\x96\xa1\x1b\xb0|\x88\x17\xcar\xa5J\x00\x12\x04',
        "scopes": 1,
        "allowed_contracts": [],
        "allowed_groups": [],
        "rules": [],
    },
]

Parameters:: hash (UInt256) – hash identifier of the transaction
Returns:: VM state of the transaction

get_transaction_vm_state(hash_: UInt256) → VMState

Gets the VM state of a transaction.

>>> get_transaction_vm_state(UInt256(b'\x29\x41\x06\xdb\x4c\xf3\x84\xa7\x20\x4d\xba\x0a\x04\x03\x72\xb3\x27\x76\xf2\x6e\xd3\x87\x49\x88\xd0\x3e\xff\x5d\xa9\x93\x8c\xa3'))
VMState.HALT

Parameters:: hash (UInt256) – hash identifier of the transaction
Returns:: VM state of the transaction

current_hash: UInt256

Gets the hash of the current block.

>>> current_hash
b'\x3e\x65\xe5\x4d\x75\x5a\x94\x90\xd6\x98\x3a\x77\xe4\x82\xaf\x7a\x38\xc9\x8c\x1a\xc6\xd9\xda\x48\xbd\x7c\x22\xb3\x2a\x9e\x34\xea'

current_index: int

Gets the index of the current block.

>>> current_index
10908937

>>> current_index
2108690

>>> current_index
3529755

Subpackages

class Block

Bases: object

Represents a block.

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

Variables:

hash (UInt256) – a unique identifier based on the unsigned data portion of the object
version (int) – the data structure version of the block
previous_hash (UInt256) – the hash of the previous block
merkle_root (UInt256) – the merkle root of the transactions
timestamp (int) – UTC timestamp of the block in milliseconds
nonce (int) – a random number used once in the cryptography
index (int) – the index of the block
next_consensus (UInt160) – the script hash of the consensus nodes that generates the next block
transaction_count (int) – the number of transactions on this block

class Signer

Bases: object

Represents a signer.

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

Variables:

account (UInt160) –
scopes (WitnessScope) –
allowed_contracts (list[UInt160]) –
allowed_groups (list[UInt160]) –
rules (list[WitnessRule]) –

class WitnessRule

Bases: object

Represents a witness rule.

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

Variables:

action (WitnessRuleAction) –
condition (WitnessCondition) –

class WitnessCondition

Bases: object

Represents a witness condition.

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

Variables:: type (WitnessConditionType) –

class WitnessConditionType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

BOOLEAN = 0

NOT = 1

AND = 2

OR = 3

SCRIPT_HASH = 24

GROUP = 25

CALLED_BY_ENTRY = 32

CALLED_BY_CONTRACT = 40

CALLED_BY_GROUP = 41

class WitnessRuleAction(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

DENY = 0

ALLOW = 1

class WitnessScope(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntFlag

Determine the rules for a smart contract CheckWitness() sys call.

NONE = 0: No Contract was witnessed. Only sign the transaction.

CALLED_BY_ENTRY = 1: Allow the witness if the current calling script hash equals the entry script hash into the virtual machine. Using this prevents passing CheckWitness() in a smart contract called via another smart contract.

CUSTOM_CONTRACTS = 16: Allow the witness if called from a smart contract that is whitelisted in the signer allowed_contracts attribute.

CUSTOM_GROUPS = 32: Allow the witness if any public key is in the signer allowed_groups attribute is whitelisted in the contracts manifest.groups array.

WITNESS_RULES = 64: Allow the witness if the specified rules are satisfied

GLOBAL = 128: Allow the witness in all context. Equal to NEO 2.x’s default behaviour.

class Transaction

Bases: object

Represents a transaction.

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

Variables:

hash (UInt256) – a unique identifier based on the unsigned data portion of the object
version (int) – the data structure version of the transaction
nonce (int) – a random number used once in the cryptography
sender (UInt160) – the sender is the first signer of the transaction, they will pay the fees of the transaction
system_fee (int) – the fee paid for executing the script
network_fee (int) – the fee paid for the validation and inclusion of the transaction in a block by the consensus node
valid_until_block (int) – indicates that the transaction is only valid before this block height
script (bytes) – the array of instructions to be executed on the transaction chain by the virtual machine

class VMState(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

Represents the VM execution state.

NONE

Indicates that the execution is in progress or has not yet begun.

HALT

Indicates that the execution has been completed successfully.

FAULT

Indicates that the execution has ended, and an exception that cannot be caught is thrown.

BREAK

Indicates that a breakpoint is currently being hit.