Hi,

All the following happens to me using the latest versions of Emmett and Emmett Rest:

emmett 2.5.6
emmett-crypto 0.5.1
emmett-rest 1.5.2

All my models inherit from Signature

class TimeStamp(Model):
    created_at = Field('datetime')
    updated_at = Field('datetime')

    default_values = {
        'created_at': lambda: local_now(),
        'updated_at': lambda: local_now(),
    }

    update_values = {
        'updated_at': lambda: local_now(),
    }

class Signature(TimeStamp):
    refers_to(
        {'created_by': 'User'},
        {'updated_by': 'User'}
        )

    default_values = {
        'created_by': lambda: get_user(),
        'updated_by': lambda: get_user(),
    }

    update_values = {
        'updated_by': lambda: get_user(),
    }

What I am seeing that I have update a record from the API Rest, the updates are not worked, this is updated_at and updated_by maintain the value of when the record was created