Run rules when windows appear and commands when focus changes.
Limit Window titles may appear after the detection callback; focus callbacks should not rely on execution order.
2 open-source tools on osfeed do this, in 2 ways. Each entry says how, and where it falls short. Read the tool's page before you rely on it.
Limit Window titles may appear after the detection callback; focus callbacks should not rely on execution order.
Limit Sticky, sub-layer, opacity, and scratchpad rules require partially disabled SIP.
Hear when any tool adds, fixes or changes a way to do this, including tools that join osfeed later.