The React 19 port of the Tinker reference app (vercel-tinker-r3t) — the simplest of the four reference apps, purpose-built to validate the action–state pattern in isolation. The screenshot shows yellow selected in the color swatch row, with color: yellow and sample: 53,77,57,19,23 displayed below. Refresh (blue) and clear (red) buttons, "click a button... 3" counter. Tailwind 4.2.2 noted top-right.
Tinker is deliberately minimal — no animation, no external API, no complex layout. Its role in the suite is to be the baseline: if action–state works correctly in Tinker, the same pattern can be trusted in Funnel, Autos, and Sudoku. It's also the first port to a new framework, making it the canary for any framework-specific quirks in the action–state wiring.
Comparing this to gallery://vercel-funnel-r3t shows the same color swatch pattern and counter mechanic shared across the suite — Tinker is where that pattern was established.