Tag             26
   Data Item       array [classname, constructargs...]
   Semantics       Serialised Perl object with classname and constructor arguments
   Contact         Marc A. Lehmann <>


The perl-object tag in CBOR can be used to serialise Perl 5 objects into CBOR.

The tagged value must be a CBOR array with at least one element. The first element specifies a classname to use in Perl (it can, but does not need to be a string - the stringified form will be used as classname).

The encoder and decoder should serialise/deserialise the object using the Types::Serialiser object serialisation protocol. For this, the object's class must have FREEZE and THAW methods that are called like this:

   @constructargs = $object->FREEZE ("CBOR");
   $object = $class->THAW ("CBOR", @constructargs);

If the class or method is currently not available, the decoder may try to load a Perl module of the same name and retry the method call.


Example of a hypothetical My::DateTime representation using a unix timestamp:

   26(["My::DateTime", 12345678])

   d8 1a                             # tag(26)
      82                             # array(2)
         6c                          # text(12)
            4d793a3a4461746554696d65 # "My::DateTime"
         1a 00bc614e                 # unsigned(12345678)

Example of the corresponding FREEZE method:

   sub My::DateTime::FREEZE {
      my ($self, $model) = @_;


Example of the corresponding THAW method:

   sub My::DateTime::THAW {
      my ($class, $model, $seconds) = @_;

      $class->new_from_seconds ($seconds)


This section lists known implementations of this extension (drop me a mail if you want to be listed here).

* [Perl] CBOR::XS (reference implementation)