Base UI

What it does

When your agent uses it

• Refining unstyled primitive components and behavior-heavy UI such as overlays
• Defining custom component APIs

Example prompts

• “/base-ui”

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

1. 1Confirm @base-ui/react is present in the target workspace package.json.
2. 2Open the exact docs page from reference-links.md for the primitive you need.
3. 3Implement behavior with Base UI primitives first, then layer project styles (cn, tokens, Tailwind).
4. 4Convert any Tailwind v4-only example classes if the target workspace is still on Tailwind v3.
5. 5Validate keyboard navigation, focus states, and screen-reader output.
6. 6Run local quality gates (typecheck/lint/tests relevant to changed scope).

What it can do on your machine

Read from SKILL.md and the folder at commit 225c02e. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are typescript).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Base UI loads about 1.2k tokens when it runs. Until then it costs about 96 tokens; SKILL.md has 452 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~96

When it runs · the whole SKILL.md, loaded when a task matches

~1.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from Asymmetric-al/core at commit 225c02e, republished under its AGPL-3.0 licence (© Asymmetric-al). 452 words, ~1,180 tokens.

name

base-ui

description

Build accessible, composable UI with @base-ui/react primitives and project styling tokens. Use when creating or refining unstyled primitive components and behavior-heavy UI such as overlays, menus, popovers, dialogs, and form controls, or defining custom component APIs. Prefer the moai-library-shadcn skill when copied-in shadcn components are the primary implementation path.

import { Field } from "@base-ui/react/field";

type FieldShellProps = {
  label: string;
  error?: string;
  children: React.ReactNode;
};

export function FieldShell({ label, error, children }: FieldShellProps) {
  return (
    <Field.Root invalid={Boolean(error)} className="grid gap-1.5">
      <Field.Label className="text-sm font-medium">{label}</Field.Label>
      {children}
      {error ? (
        <Field.Error match className="text-sm text-destructive">
          {error}
        </Field.Error>
      ) : null}
    </Field.Root>
  );
}

When docs examples rely on Tailwind v4-only utilities,
replace them with equivalent v3-safe utilities before commit.

© Asymmetric-al, AGPL-3.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file in .agents/skills/base-ui of Asymmetric-al/core.

• SKILL.md
• reference-links.md

Open the folder on GitHubat commit 225c02e