A 13MB Cursor Monitor: AppKit, Undocumented APIs, Zero Dependencies

My company recently started supporting Cursor, so I jumped in. But checking usage meant opening the dashboard every time — and if Max mode was on without me noticing, requests burned through fast. I wanted a glanceable counter, always visible . So I built one. V1: SwiftUI — Done in a Weekend, Regretted in a Week The first version took two days. SwiftUI's MenuBarExtra made it trivial to get something on screen. I was proud of it. Then I checked Activity Monitor. 56 MB of memory. For a menu bar app that displays a single number. I tried to optimize — removed animations, simplified views, cached aggressively. Nothing moved the needle. The SwiftUI runtime itself was the cost. MenuBarExtra allocates a full SwiftUI rendering pipeline whether you need it or not. For a "set and forget" menu bar app that runs 24/7, 56MB felt like a tax I shouldn't be paying. The Rewrite: Burning It All Down I threw out the entire UI layer and rebuilt everything in pure AppKit. NSStatusItem , NSPopover , NSViewC