[alistairjcbrown]

Do many routers make that data easily accessible for automated use? From my experience, it requires work to get at that data.

[ShinyCyril]

It depends on your definition of easily accessible. For example, on my TP-Link W8961N you can use Python's Requests library, Beautiful Soup and HTTP Basic Auth to retrieve and parse the client list.

[OJFord]

Seeing as how rarely router firmware is upgraded (and even then, surely less likely the UI!) - I think you're pretty safe automating a scrape of the HTML table.