Right now we have a low level HTTP API that allows creating/deleting config nodes with given paths. The bad thing is that the user needs to know the config syntax.
Config syntax isn't exactly constant either—we sometimes change it between LTS releases.
This is bad for development of management tools. Our plan for the local web GUI is to provide a simplified interface for novice users and helpdesk personnel, for example. Other people may want to develop tools similar in spirit but different in their look or behaviour.
It would be handy to have a more high level API that is relatively abstract and doesn't depend on precise config syntax. For example: /firewall/rule/create/ with abstract POST data.
We need to first define endpoints, then actually implement them.