Stream subscription by category

Hello everyone,

Is there any way to subscribe events by category using just protobuf API?

I think I can do that by creating projection, which would create stream and then subscribe to it, but is it the only way to do that?



There are three ways.

You can either listen to all the streams that get created in that
category and subscribe to each individually. Or you can write a
projection that does this. While on a SingleNode its a relatively
simple operation it would be quite expensive in a distributed
environment. In a singlenode you would probably just prefer to
subscribe to $all and filter.