---
features:
  - Add a new webhook notifier using trust authentication. When using the
    'trust+' URL prefix, Zaqar will create a Keystone trust for the user, and
    then use it when a notification happens to authenticate against Keystone
    and send the token to the endpoint.
  - Support 'post_data' and 'post_headers' options on subscribers, allowing
    customization of the payload when having a webhook subscriber. The
    'post_data' option supports the '$zaqar_message$' string template, which
    will be replaced by the serialized JSON message if specified.