clients dont really explain what a trending feed is.
here is a basic trending algorithm you can make with couple of bash commands:
- query all kind 7 reactions
- select e-tags
- sort these event ids by number of occurences in decending order
- query first n events
this is by no means perfect algorithm, as an attacker could hijack this by spamming e tags in kind 7 events, but unless this happens, it works
as opposed to obfuscated algorithms used by popular ui clients, at least one knows what the algorithm does