How to filter the subscribed contracts events with their topics?

Question

I need to subscribe to my smart-contract events (#[ink(event)]). So I state_subscribeStorage to "System.Events" storage key. But then I get all system events of all smart contracts in my chain. Can I save websocket traffic and have only events that I am interested in?

Since substrate contract events have topics (#[ink(topic)]), there has to be a way to filter the received events by the topics. Or else why are the topics introduced?

I know about external indexers. But I would like to be simple and use only the substrate node.

Answer 1

You can use useink and the hook useEvents, which will subscribe to a contract's events. Here is an example using it and decoding the events that are emitted.