A GraphQL subscription is essentially a query where the client receives an event whenever the value of any field changes upstream. The Hasura GraphQL engine supports subscriptions for all kind of queries. All the concepts of :doc:`queries <../queries/index>` hold true with subscriptions as well.
Convert a query to a subscription
You can turn any query into a subscription by simply replacing
subscription as the operation type.
Hasura follows the GraphQL spec which allows for only one root field in a subscription.
.. toctree:: :maxdepth: 1 :hidden: Sample use cases <use-cases>