It is possible to query facets using Custom DQL and remote data types.
Example Custom DQL query:
type UserTweet @remote {
screen_name: String
}
query {
queryUserTweet: [UserTweet] @custom(dql: """
query {
queryUserTweet(func: type(User)) {
screen_name: screen @facets(name)
}
}
""")
}
It is however not possible to mutate facets using custom DQL as custom DQL does not support mutations.
We are working on adding support for Facets with GraphQL.
Related RFC and discussion: Facets in GraphQL