contract

class CallFlags(value)

Bases: enum.IntFlag

Defines special behaviors allowed when invoking smart contracts, e.g., chain calls, sending notifications and modifying states.

NONE

Special behaviors of the invoked contract are not allowed, such as chain calls, sending notifications, modifying state, etc.

READ_STATES

Indicates that the called contract is allowed to read states.

WRITE_STATES

Indicates that the called contract is allowed to write states.

ALLOW_CALL

Indicates that the called contract is allowed to call another contract.

ALLOW_NOTIFY

Indicates that the called contract is allowed to send notifications.

STATES

Indicates that the called contract is allowed to read or write states.

READ_ONLY

Indicates that the called contract is allowed to read states or call another contract.

ALL

All behaviors of the invoked contract are allowed.

class Contract

Bases: object

Represents a contract that can be invoked.

Variables

  • id (int) – the serial number of the contract

  • update_counter (int) – the number of times the contract was updated

  • hash (UInt160) – the hash of the contract

  • nef (bytes) – the serialized Neo Executable Format (NEF) object holding of the smart contract code and compiler information

  • manifest (ContractManifest) – the manifest of the contract

class ContractManifest

Bases: object

Represents the manifest of a smart contract 1.

When a smart contract is deployed, it must explicitly declare the features and permissions it will use.

When it is running, it will be limited by its declared list of features and permissions, and cannot make any behavior beyond the scope of the list.

1

For more details, see NEP-15.

Variables

  • name (str) – The name of the contract.

  • groups (List[ContractGroup]) – The groups of the contract.

  • supported_standards (List[str]) – Indicates which standards the contract supports. It can be a list of NEPs.

  • abi (ContractAbi) – The ABI of the contract.

  • permissions (List[ContractPermission]) – The permissions of the contract.

  • trusts (List[ContractPermissionDescriptor] or None) –

    The trusted contracts and groups of the contract.

    If a contract is trusted, the user interface will not give any warnings when called by the contract.

  • extras (str) – Custom user data as a json string.

call_contract(script_hash: boa3.builtin.type.UInt160, method: str, args: Sequence = (), call_flags: boa3.internal.neo3.contracts.contracttypes.CallFlags = <CallFlags.ALL: 15>) → Any

Calls a smart contract given the method and the arguments.

Parameters

  • script_hash (UInt160) – the target smart contract’s script hash

  • method (str) – the name of the method to be executed

  • args (Sequence[Any]) – the specified method’s arguments

  • call_flags (CallFlags) – the CallFlags to be used to call the contract

Returns

the result of the specified method

Return type

Any

Raises

Exception – raised if there isn’t a valid CallFlags, the script hash is not a valid smart contract or the method was not found or the arguments aren’t valid to the specified method.

create_contract(nef_file: bytes, manifest: bytes, data: Optional[Any] = None) → boa3.builtin.interop.contract.contract.Contract

Creates a smart contract given the script and the manifest.

Parameters

  • nef_file (bytes) – the target smart contract’s compiled nef

  • manifest (bytes) – the manifest.json that describes how the script should behave

  • data (Any) – the parameters for the _deploy function

Returns

the contract that was created

Return type

Contract

Raises

Exception – raised if the nef or the manifest are not a valid smart contract.

update_contract(nef_file: bytes, manifest: bytes, data: Optional[Any] = None)

Updates the executing smart contract given the script and the manifest.

Parameters

  • nef_file (bytes) – the new smart contract’s compiled nef

  • manifest (bytes) – the new smart contract’s manifest

  • data (Any) – the parameters for the _deploy function

Raises

Exception – raised if the nef and the manifest are not a valid smart contract or the new contract is the same as the old one.

destroy_contract()

Destroy the executing smart contract.

get_minimum_deployment_fee() → int

Gets the minimum fee of contract deployment.

Returns

the minimum fee of contract deployment

get_call_flags() → boa3.internal.neo3.contracts.contracttypes.CallFlags

Gets the CallFlags in the current context.

create_standard_account(pub_key: boa3.builtin.type.ECPoint) → boa3.builtin.type.UInt160

Calculates the script hash from a public key.

Parameters

pub_key (ECPoint) – the given public key

Returns

the corresponding script hash of the public key

Return type

UInt160

create_multisig_account(m: int, pub_keys: List[boa3.builtin.type.ECPoint]) → boa3.builtin.type.UInt160

Calculates corresponding multisig account script hash for the given public keys.

Parameters

  • m (int) – the minimum number of correct signatures need to be provided in order for the verification to pass.

  • pub_keys (List[ECPoint]) – the public keys of the account

Returns

the hash of the corresponding account

Return type

UInt160

NEO: boa3.builtin.type.UInt160

NEO’s token script hash.

GAS: boa3.builtin.type.UInt160

GAS’ token script hash.