Use JS expressions to filter execution of Github Actions on event payloads. The JSON parsed event is available as event. Pass the expression as the args to the action.

An example workflow to block deleted branches:

workflow "Remove" {
  on = "push"
  resolves = ["on deleted branches only"]
}

action "on deleted branches only" {
  uses = "dschep/filter-event-action@master"
  args = "event.deleted"
}