Navigation menu

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<nav class="navigation-menu" data-navigation-menu aria-label="Product">
  <ul class="navigation-menu__list">
    <li class="navigation-menu__item"><a class="navigation-menu__link" href="#" aria-current="page">Home</a></li>
    <li class="navigation-menu__item">
      <details class="navigation-menu__branch">
        <summary class="navigation-menu__trigger">Product</summary>
        <div class="navigation-menu__panel" data-layout="mega">
          <div class="navigation-menu__group">
            <p class="navigation-menu__group-title">Build</p>
            <a href="#">DSL apps<small>Ship CRUD + workflows</small></a>
            <a href="#">Hyperparts<small>Gallery + contracts</small></a>
          </div>
          <div class="navigation-menu__group">
            <p class="navigation-menu__group-title">Operate</p>
            <a href="#">Deploy<small>Plan + target</small></a>
            <a href="#">Observability<small>Pulse + fitness</small></a>
          </div>
        </div>
      </details>
    </li>
    <li class="navigation-menu__item">
      <details class="navigation-menu__branch">
        <summary class="navigation-menu__trigger">Resources</summary>
        <div class="navigation-menu__panel">
          <div class="navigation-menu__group"><a href="#">Docs</a><a href="#">Changelog</a><a href="#">Community</a></div>
        </div>
      </details>
    </li>
    <li class="navigation-menu__item"><a class="navigation-menu__link" href="#">Pricing</a></li>
  </ul>
</nav>

Server exchange

This Hyperpart has no server exchange — it is presentation or client chrome only. htmx does not issue a request on this part's behalf. If you put an affordance (hx-*) on a control that uses this markup, that action's exchange belongs to the action, not this part. See Swap contract for host-owned envelopes.

Swap contract

Agent-visible HTMX topology (ADR-0054 / decision 0012). exchange envelope = what the response may re-emit relative to the persistent slot (body_only | outer | none | host_owned | document). dual-lock validates part markup only — not this envelope. Stem: stems/morph-safe-hypermedia.md; decision: docs/decisions/0012-swap-identity-contract.md.

No host HTMX exchange on this part — presentation or client chrome only. exchange envelope: n/a.

If a host wraps this markup in hx-*, that host owns the swap contract (sole identity + envelope). Prefer innerMorph / outerMorph for stable slots; replacement for flash; body-only responses under inner swaps.

Envelope response examples

This part has no owned exchange (envelope n/a). If a host adds hx-*, that host’s envelope applies — typically body_only:

<!-- Host wraps this presentation part with hx-* (host owns envelope) -->
<!-- Prefer: hx-swap="innerMorph" hx-target="#panel-body" -->
<!-- Server returns body_only interior for #panel-body -->
<div class="dz-stack">content…</div>

Do not re-own the slot:

<!-- WRONG: server returns the presentation root with a new id every poll -->
<div id="navigation-menu-root" data-dz-region>…</div>

How to use it

Seams

• `[data-navigation-menu]` / `.navigation-menu` scopes exclusive open
• `details.navigation-menu__branch` + `summary.navigation-menu__trigger`
• Submenu affordance: CSS `::after` chevron on trigger (1rem, rotates open)
• pick-a-surface: top product/site go-to → navigation-menu (not menubar / menu / sidebar)

Do / Don't

Pitfalls

• Native details allow multi-open and ignore outside click — ship navigation-menu.js
• Do not confuse with menubar (app File/Edit) or app-shell sidebar
• Gallery: href=# is product-shaped stand-in; MOCK_HTMX inert-hash handler stops host scroll — do not 'fix' Copy this to void(0)
• Do not reintroduce Unicode ▾ spans or 0.65em carets — match accordion disclosure chrome (stem affordance-disclosure-chrome)
• do not use navigation-menu for local action lists — that is menu

Keyboard / AT

• aria-label on root nav
• Keyboard: Enter/Space toggles summary; Escape dismisses open panels
• Chevron is decorative (CSS); details/summary carry expand semantics

Related parts

menubar app-shell

DOM contract

What the emitted HTML must satisfy — the table is the required surface; Python under contracts/ is the package-internal dual-lock CI runs (tests/test_contracts.py), not an app route. Standalone HTMX4: implement the API so responses match this markup. Dazzle: the agent emits SSR that already satisfies it. Do not invent attrs outside these tables. For request/response wiring see Server exchange.

contracts/navigation_menu.py

Required in the DOM: root [data-navigation-menu] (part navigation-menu). Emit only these attributes — inventing extras is fine only if controllers ignore them; omitting required ones fails CI (tests/test_contracts.py).

Module source

Import path is monorepo/package-local (from contracts._kit import …). Source-token form often uses data-*; gallery demos above are unprefixed. Do not copy this into app routes.

"""HYPERPART: navigation-menu — product nav exclusive-open root contract."""

from contracts._kit import DomContract, Node, Present

DOM_CONTRACT = DomContract(
    part="navigation-menu",
    root="[data-dz-navigation-menu]",
    nodes=(
        Node(
            "[data-dz-navigation-menu]",
            attrs={"data-dz-navigation-menu": Present()},
        ),
    ),
)

__all__ = ["DOM_CONTRACT"]

Notes

Source files

One logical Hyperpart, 4 code items (CSS layered, JS bundled). Bound by HYPERPART: navigation-menu — python tools/hyperpart.py navigation-menu lists them.

site/registry.py · contracts/navigation_menu.py · components/navigation-menu.css:1 · controllers/dz-navigation-menu.js