Show HN: I reverse engineered Apple's video wallpapers

Original Article ↗ Hacker News Discussion ↗

Project capabilities & use cases

  • Tool injects custom videos into macOS’s native video wallpaper pipeline, letting users:
    • Use personal videos for desktop, lock screen, and optionally keep them playing after login.
    • Mix custom videos alongside Apple’s “Aerial” wallpapers rather than replacing them.
  • Works specifically with WallpaperAgent / com.apple.wallpaper; separate private APIs exist for screensavers, but those are distinct.
  • Any video file can be used; some commenters wish for specially designed sets that visualize battery, thermals, etc., leveraging metadata features described in the repo.

Reliability, future compatibility & Apple behavior

  • Some expect Apple might break private API access; others note the relevant framework has been stable for years and doubt it’s a priority for Apple.
  • Author clarifies the app integrates with Apple’s own pipeline, so custom videos shouldn’t be silently deleted or redownloaded.

User experience, performance, and issues

  • Mixed feelings on motion:
    • Some love video backgrounds and nostalgia for older “shiny” UIs (Vista, Active Desktop, X11 tricks).
    • Others find moving wallpapers distracting or nausea-inducing, especially on large/ultrawide displays; many prefer movement only on lock screen.
  • A user reports severe macOS data usage issues from Apple’s wallpapers being repeatedly deleted and redownloaded (unrelated to this app, but a motivator to avoid Apple’s default behavior).
  • One user sees frequent lock-screen stutters on an M3 Pro; another notes lock-screen videos conflict with “Adaptive” refresh rate on certain displays and require a fixed rate.
  • Some remove Apple’s large (tens of GB) wallpaper video bundles to reclaim disk space.

Technical reverse engineering & related work

  • Multiple commenters discuss reverse engineering:
    • Private wallpapers vs private screensaver .appex frameworks.
    • Shared playback between lock screen and desktop via surface switching.
    • Procedurally updated wallpaper (e.g., “Macintosh”) that renders current date/time from bundled scripts.
  • Other tools and prior efforts are mentioned (e.g., Aerial screensaver, cross‑platform alternatives, older Windows/X11 hacks).

AI-assisted development

  • The project’s site and some code/architecture were co-authored with an AI model.
  • Discussion includes interest in prompts/skills used to steer the AI, especially around concurrency and design.