core-admin/qubes-rpc/qubes.FeaturesRequest

#!/usr/bin/env python2

import os
import qubes

PREFIX = '/features-request/'

app = qubes.Qubes()
vm = app.domains[os.environ['QREXEC_REMOTE_DOMAIN']]
vm.fire_event('features-request',
    untrusted_features={key[len(PREFIX):]: vm.qdb.read(key)
        for key in vm.qdb.list(PREFIX)})
app.save()