Vercel Labs releases UI SDK with 50+ UI behaviors for AI coding agents

Vercel Labs released UI SDK, an open-source beta library of 50+ headless UI behaviors that coding agents assemble into accessible components for React, Vue, Svelte, Solid and Web Components. The 6 npm packages are at 0.1.0-beta.1 under Apache-2.0, and a createAgent bridge lets agents snapshot UI state and act on it without screenshots. Vercel's self-reported test on a single settings task showed 69% fewer tool calls and time falling from 41 s to 16 s, though the sample is 1 task and 3 runs.