Is Reactive GraphQL even specified? I thought that in the current state GraphQL only defines single queries (snapshots) of data, and not continuos update notifications. Forgive me if I have missed it - I have not followed GraphQL&#x2F;Relay apart from a very basic look at it.<p>Without having an open specification Meteors implementation might end up completly different or incompatible to other (Reactive) GraphQL implementations.<p>Despite that, I think that implementing a reactive GraphQL backend will be very hard, and it would only work good if all of the sub-data-sources that you use in your backend support reactivity (subscriptions) as well. If they do, then you have to subscribe to all possible data sources that are mentioned in the query, and update the current state when one of these changes. If the update requires you to fetch an additional data source (e.g. you must fetch other indexes of data which are provided by another source), you must even dynamically subscribe&#x2F;unsubscribe on updates of other sources.<p>And how can you provide traditional REST APIs (or even query-based GraphQL endpoints) as reactive endpoints? The best you can do is probably implement polling (rerunning) the query on the backend over and over.