JetUI is an open source Rails 8 component library we’ve been building at JetRockets — 29 components, 8 form fields, and 61 UI blocks, built on ViewComponent, Tailwind CSS 4, and Stimulus. Copy-paste, not a dependency. We’re just about to hit 5,000 downloads.

Part of why we built it: coding agents generate good React because that pattern saturates their training data, and generate noticeably worse Rails views because modern Rails view code is thinner and far less represented. A documented component library gives the agent something to target — a gap the Rails Foundation is now measuring directly with Agents on Rails.