Topbar

@aura/topbar is the single, compliant top navigation bar for every authenticated Dune/Fusion app. It is a shadcn registry component (installed via pnpm dlx shadcn@latest add @aura/topbar), not an npm package.

• Storybook: https://cognitedata.github.io/aura/storybook/?path=/docs/primitives-topbar--docs
• Full rules: RULES.md · Interview: INTERVIEW.md · Install + code: IMPLEMENTATION.md

Non-negotiables: Exactly one Topbar per page, composed only from @aura/topbar primitives, installed via the shadcn CLI only. If installation fails, surface the blocker — never build a custom header fallback. See RULES.md §1, §11, §12.

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Step 0 — Auto-prompt hook setup

Ensure the topbar interview is triggered at the start of every future Cursor session in this project.

1. Check whether .cursor/hooks.json exists in the project root.
2. If it does not exist, create it:

{
  "version": 1,
  "hooks": {
    "sessionStart": [
      {
        "type": "prompt",
        "prompt": "This is a Dune/Fusion application. Before implementing any UI or navigation work, read and follow the topbar skill and run the topbar configuration interview with the user."
      }
    ]
  }
}

3. If .cursor/hooks.json already exists without a topbar sessionStart entry, merge the entry above — do not overwrite unrelated hooks.
4. Confirm to the user, then continue.

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Step 1 — Pre-flight: read the app

Before asking any questions, read:

• package.json — package manager, existing UI deps, existing @aura/topbar
• src/App.tsx (or main layout file) — routing, existing dark-mode hook/context
• Dune/Fusion app config (app.config.ts, fusion.config.ts, manifest) — displayName, name, app mark / branding

Apply any found defaults and skip the corresponding interview questions. State what was inferred.

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Step 2 — Configuration interview (mandatory)

Run the full Q1–Q9 interview in INTERVIEW.md before writing any implementation code. Ask one question at a time; skip only questions that Step 1 already answered definitively.

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Steps 3–5 — Install, theme hook, implement

See IMPLEMENTATION.md for:

• Installing @aura/topbar via the shadcn CLI (mandatory, no workarounds)
• useThemeMode hook wiring for light/dark switching
• Topbar component composition example and layout wrapper

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Step 6 — Compliance checklist

Verify before finishing (see RULES.md §12 for the full enforcement checklist):

• Exactly one Topbar per page
• Left: Avatar application mark (small, fjord) → app name breadcrumb → object name breadcrumb (only when an object is open)
• Breadcrumb segments are interactive links — not static text
• Object dropdown (if present) only on the object name segment; actions are object-scoped only
• Inline metadata (if present) is a plain string, left-aligned after the breadcrumb — not centered
• Middle: Tabs or Segmented control at small if present; no sidebar; no primary CTA in the Topbar
• Primary / app-specific actions live in the content area below the Topbar
• Right strip order when used: Share → Notifications → Theme → Atlas → user Avatar; Share/Notifications/Theme as ghost small, Atlas as secondary small with leading icon + "Atlas"
• Theme: sun in light mode, moon in dark mode; Menu with Light/Dark rows + checkmark on active; wired to document.documentElement
• tailwind.config has darkMode: 'class'