Build with ui-sdk

ui-sdk is a library of UI behaviors: keyboard navigation, focus, selection, dismissal, popups, drag and drop and the ARIA they need. Its components are built from those behaviors and render no styles of their own, in React, Vue, Svelte, Solid and web components. @ui-sdk/core/web.css gives them an optional default look. When a component is missing, you build it from the same behaviors in @ui-sdk/core, and it gets the same keyboard, focus, server rendering and right to left support.

Read first

The docs for the installed version ship in each package, as Markdown:

• node_modules/@ui-sdk/<framework>/docs/llms.txt is the index. Read it first. <framework> is react, vue, svelte, solid or web.
• Then read only the pages your task needs, like docs/components/select.md. Don't read the whole docs/ folder; it's large.
• An interface built from our components doesn't need docs/core.md. Only path 2 below does, and even then you search it by heading: it's over 300 KB. docs/rendering.md sits next to it in the same docs/ folder.
• Don't read compiled JavaScript in dist/*.js, even to debug. The docs and the .d.ts types are the API; when they don't answer, write a small test that tries it.

The same docs are online at https://ui-sdk.dev/docs. Prefer the installed copy: it matches the version in the project.

A page with no build step, like an Artifact, installs nothing: it loads https://ui-sdk.dev/web.js and web.css with two tags. Read https://ui-sdk.dev/web.md instead of llms.txt. It's the web components docs in one file, for that page, and references/web-components.md has the rest.

Otherwise, if no @ui-sdk package is installed yet, install @ui-sdk/core and the framework's package with the project's package manager. In a Nuxt 4 or newer app using @ui-sdk/vue, also add "@ui-sdk/vue" to modules in nuxt.config.ts.

Pick your path

1. Build an interface from our components, like a settings page, a form or a command palette: read references/build-interface.md.
2. Build a component or behavior ui-sdk doesn't ship, or extend one of ours: read references/create-component.md.

Most interfaces only need path 1. When one part of it needs a component we don't have, follow path 2 for that part.

Every path ends the same way:

3. Make it agent-ready: references/agent-ready.md.
4. Test it: references/testing.md.

Rules for every path

• Import from entries. Each component has its own entry, like @ui-sdk/react/select. Import components from there, not from a package root. Never import @ui-sdk/core/internal/*.
• One shape everywhere. A root and its parts, nested as the component page's Composition shows. Change a part's element with render, never an as prop.
• Default or controlled. defaultValue to start, or value with onValueChange(value, details) to control it (each framework's idiom: v-model in Vue, bind:value in Svelte, properties and events in web components). details has reason, source and cancel().
• Name every control. Use the component's label part (FieldLabel, SelectLabel, DialogTitle), or aria-label when there's no visible text. People using screen readers and agents both find controls by name.
• Style from state. Target data-slot and state attributes like data-open or data-pressed, and the CSS variables each component lists. Never inline styles for state, and never generated ids. When the app uses web.css, read references/styles.md first: it draws icons and sets sizes you can't see in the markup.
• Declare the ui-sdk layer. Put @layer ui-sdk; at the top of the global stylesheet, above @import "tailwindcss" if there is one.
• Check color. Text needs 4.5:1 against what's behind it, and control edges, focus rings and state fills 3:1. jsdom can't see color, so check it in a real browser.
• Key lists by value or id, never by index.
• Right to left needs no provider. Components read the direction from the page.
• Comments are rare. Write one only when a reader would get the code wrong without it, like a browser quirk or a trade-off, in one or two lines. Never comment what the code does, what a value is, or which section starts here, and no JSDoc blocks on app code.
• Don't hand-roll what we ship. Before you write any role= attribute, look for the component in the table in references/build-interface.md. A div with role="listbox", "menu", "dialog", "tablist", "separator", "switch", "slider", "radiogroup", "toolbar" or "tree" next to an installed ui-sdk package is almost always a bug.

When you're done

1. Typecheck. If the root tsconfig.json has "files": [] and references, npx tsc --noEmit checks nothing: run npx tsc -b or npx tsc --noEmit -p <app config>. For Svelte, run svelte-check; for Vue, vue-tsc.
2. Write and run tests (see testing.md). Every task gets tests, and every interface gets at least the agent test from agent-ready.md. If a test finds a bug in code you were asked only to test, mark it test.fails (or it.fails) with a one-line reason, report the bug, and leave the suite green.
3. Read every comment in your diff. Delete it unless it names a browser quirk, an APG rule or a trade-off, and cut what's left to two lines. Turn JSDoc on app code into a plain comment or delete it. Never tell the reader to replace something.
4. Report each command you ran with its exit code, anything you couldn't check, and anything the docs or types got wrong or left out.