NAME
Bitcoin::Crypto::PSBT - Partially Signed Bitcoin Transactions
SYNOPSIS
use Bitcoin::Crypto qw(btc_psbt);
# import PSBT from a serialized form
my $psbt = btc_psbt->from_serialized([base64 => $psbt_string]);
# dump in readable format
print $psbt->dump;
# get a single PSBT field
my $field = $psbt->get_field('PSBT_GLOBAL_TX_VERSION');
# get decoded field key and value
my $key = $field->key;
my $value = $field->value;
# get all PSBT fields of a given type
my @fields = $psbt->get_all_fields('PSBT_GLOBAL_PROPRIETARY');DESCRIPTION
This is a class implementing the PSBT format as described in BIP174 and BIP370. It currently supports versions 0 and 2 of the spec. It allows serialization, deserialization, validation and access to PSBT fields. It currently does not support the roles defined by the PSBT documents, so all the operations on PSBTs (like adding inputs or creating a final transaction out of it) must be done manually.
PSBT consists of a number of maps: one global, one for each transaction input and one for each transaction output. Each map holds a number of fields. Each field has a value and can optionally have extra key data.
INTERFACE
Attributes
maps
An array reference of PSBT internal maps - objects of class Bitcoin::Crypto::PSBT::Map. It should seldom be handled manually - use "get_field", "get_all_fields" and "add_field" to access fields of specific map.
Methods
new
$psbt = $class->new(%args)This is a standard Moo constructor, which can be used to create the object. It takes arguments specified in "Attributes".
Returns class instance.
version
$version = $object->version()Returns the version of the PSBT (0 or 2).
input_count
$int = $object->input_count()Returns the number of inputs the PSBT defines.
output_count
$int = $object->output_count()Returns the number of outputs the PSBT defines.
get_field
$field = $object->get_field($field_type_name, $map_index = undef)Tries to get a field of $field_type_name as defined in BIP174, for example PSBT_GLOBAL_UNSIGNED_TX. If the field is from input or output maps, it also requires $map_index to be passed (0-based index of the input or output).
Returns an instance of Bitcoin::Crypto::PSBT::Field, which you can use to access key and value data.
If there isn't exactly one field with this type in the map, it will throw an exception. This allows you to write the following without checking the return value of the function:
my $output_index_0 = $object->get_field('PSBT_IN_OUTPUT_INDEX', 0)->value;See "get_all_fields" for a variant which does not check the field count.
get_all_fields
@fields = $object->get_all_fields($field_type_name, $map_index = undef)Same as "get_field", but will return all the fields of given type from a given map. It may be used if the field exists, or to get multiple fields with different key data.
The return value is a list (not an array), so using it in scalar context will get the last found field (as opposed to a field count).
add_field
$object = $object->add_field(%field_data)
$object = $object->add_field($field_object, $map_index = undef)Adds a new field to the PSBT. It can be run either with %field_data (a hash arguments for the "new" in Bitcoin::Crypto::PSBT::Field) or with $field_object (constructed Bitcoin::Crypto::PSBT::Field) and $map_index.
If passing %field_data hash, it can contain an additional index key to represent $map_index. The field will be constructed and added to the map. Adding the index to a map triggers its validations, so it must be complete enough to pass them. For this reason, sometimes it could be more preferable to construct and fill the field by hand before adding it to the PSBT.
Note that a field cannot be used in more than one map at a time.
check
$object = $object->check()Checks the internal state of PSBT fields and throws an exception if it is invalid. Returns the object itself.
to_serialized
$serialized = $object->to_serialized()Serializes a PSBT into a bytestring. "check" is called automatically before serializing.
from_serialized
$object = $class->from_serialized($data)Deserializes the bytestring $data into a PSBT object. "check" is called automatically after deserializing.
dump
$text = $object->dump()Returns a readable description of all the maps in the PSBT.
EXCEPTIONS
This module throws an instance of Bitcoin::Crypto::Exception if it encounters an error. It can produce the following error types from the Bitcoin::Crypto::Exception namespace:
PSBT - general error with the PSBT