Vibe coding with Opus 5.5: rain pools and drips on your Mac windows in Rainpane

Tansan-7271 · reddit · 2026-09-29

Inspired by the macOS app Weatherling, a developer vibe-coded an open-source alternative called Rainpane entirely with Claude Code: rain falls behind windows, pools on top edges, runs down sides, drips from corners; fast window moves send water flying and splashing, and closing a window sheets the water down the screen. Clicks spawn droplets rendered with Liquid Glass on macOS 26+.

Implementation uses Metal shaders for water and CGWindowList for window positions. Notably, Claude couldn't see the screen, so it added a snapshot mode that renders frames to image files for self-review, and inserted temporary logs and asked the author to replay actions to debug issues. For the brand-new macOS 27 SDK, Opus 5.5 read the interface files directly and wrote a small test program to probe Liquid Glass internal values.

Caveats: private APIs may break on updates, 17% CPU on an M1 Pro with two 4K displays, tested only on the author's machine, build from source required. Code on GitHub; ARCHITECTURE.md (in Korean) documents the design decisions.

Original post →

More from coding & agent

coding & agent channel →