Credential

class cometa.common.credential.Credential(ptr)[source]

Bases: object

Represents a credential used in Cardano addresses.

A credential identifies the owner of funds or staking rights. It can be either:

A key hash (hash of a public verification key)
A script hash (hash of a Plutus or native script)

Credentials are used in:

Payment credentials (who can spend funds)
Staking credentials (who controls staking rights)

__init__(ptr)[source]

Return type:: None

__enter__()[source]

Return type:: Credential

__exit__(exc_type, exc_val, exc_tb)[source]

Return type:: None

__repr__()[source]

Return repr(self).

Return type:: str

classmethod from_hash(hash_value, credential_type)[source]

Creates a credential from a hash and credential type.

Parameters:

hash_value (Blake2bHash) – The Blake2b hash (key hash or script hash).
credential_type (CredentialType) – The credential type (KEY_HASH or SCRIPT_HASH).

Returns:

A new Credential instance.

Raises:

CardanoError – If credential creation fails.

Return type:

Credential

Example

>>> h = Blake2bHash.from_hex("00" * 28)
>>> cred = Credential.from_hash(h, CredentialType.KEY_HASH)

classmethod from_key_hash(hash_value)[source]

Creates a key hash credential.

Parameters:: hash_value (Blake2bHash | str | bytes) – The key hash as a Blake2bHash, hex string, or bytes.
Returns:: A new Credential with type KEY_HASH.
Raises:: CardanoError – If credential creation fails.
Return type:: Credential

Example

>>> cred = Credential.from_key_hash("00" * 28)

classmethod from_script_hash(hash_value)[source]

Creates a script hash credential.

Parameters:: hash_value (Blake2bHash | str | bytes) – The script hash as a Blake2bHash, hex string, or bytes.
Returns:: A new Credential with type SCRIPT_HASH.
Raises:: CardanoError – If credential creation fails.
Return type:: Credential

Example

>>> cred = Credential.from_script_hash("00" * 28)

classmethod from_hex(hex_string, credential_type)[source]

Creates a credential from a hexadecimal hash string.

Parameters:

hex_string (str) – The hexadecimal representation of the hash.
credential_type (CredentialType) – The credential type.

Returns:

A new Credential instance.

Raises:

CardanoError – If the hex string is invalid.

Return type:

Credential

Example

>>> cred = Credential.from_hex("00" * 28, CredentialType.KEY_HASH)

classmethod from_bytes(data, credential_type)[source]

Creates a credential from raw hash bytes.

Parameters:

data (bytes | bytearray) – The raw hash bytes.
credential_type (CredentialType) – The credential type.

Returns:

A new Credential instance.

Raises:

CardanoError – If credential creation fails.

Return type:

Credential

Example

>>> cred = Credential.from_bytes(bytes(28), CredentialType.KEY_HASH)

classmethod from_cbor(reader)[source]

Deserializes a Credential from CBOR data.

Parameters:: reader (CborReader) – A CborReader positioned at the credential data.
Returns:: A new Credential deserialized from the CBOR data.
Raises:: CardanoError – If deserialization fails.
Return type:: Credential

property type: CredentialType: Returns the credential type (KEY_HASH or SCRIPT_HASH).

property hash: Blake2bHash: Returns the underlying hash as a Blake2bHash object.

property hash_bytes: bytes: Returns the hash as raw bytes.

property hash_hex: str: Returns the hash as a hexadecimal string.

property is_key_hash: bool: Returns True if this is a key hash credential.

property is_script_hash: bool: Returns True if this is a script hash credential.

to_cbor(writer)[source]

Serializes the credential to CBOR format.

Parameters:: writer (CborWriter) – A CborWriter to write the serialized data to.
Raises:: CardanoError – If serialization fails.
Return type:: None

to_cip116_json(writer)[source]

Converts this object to CIP-116 compliant JSON representation.

CIP-116 defines a standard JSON format for Cardano data structures.

Parameters:: writer (JsonWriter) – A JsonWriter to write the serialized data to.
Raises:: CardanoError – If conversion fails.
Return type:: None

compare(other)[source]

Compares this credential with another credential.

Parameters:: other (Credential) – The credential to compare with.
Returns:: A negative value if this credential is less than other, zero if they are equal, a positive value if this credential is greater than other.
Return type:: int

__eq__(other)[source]

Checks equality with another Credential.

Parameters:: other (object)
Return type:: bool

__hash__()[source]

Returns a Python hash for use in sets and dicts.

Return type:: int

__lt__(other)[source]

Less than comparison.

Parameters:: other (Credential)
Return type:: bool

__le__(other)[source]

Less than or equal comparison.

Parameters:: other (Credential)
Return type:: bool

__gt__(other)[source]

Greater than comparison.

Parameters:: other (Credential)
Return type:: bool

__ge__(other)[source]

Greater than or equal comparison.

Parameters:: other (Credential)
Return type:: bool

__str__()[source]

Returns a string representation of the credential.

Return type:: str