UI SDKって見た目のとこじゃなくて振る舞いの実装だけ提供するよって感じか。いわゆるヘッドレスみたいな？
https://github.com/vercel-labs/ui
GitHubGitHub - vercel-labs/ui: A library of behaviors for agents to build the next generation of user interfaces.A library of behaviors for agents to build the next generation of user interfaces. - vercel-labs/ui
commit 04dfeba