AppShell

Preview

Installation

npx echo-ui-cli add app-shell

At a glance

Version

0.3.0

Weight

543 B · 1.3 KB of CSS (minified and gzipped; React not counted)

Reduced motion

Only colour changes on hover and selection; nothing moves.

Usage

import { AppShell } from "@/echo/app-shell";

<AppShell>
  <AppShell.Rail brand={<Wordmark />}>
    <a href="/docs">Docs</a>
  </AppShell.Rail>
  <AppShell.Sidebar label="Components">{nav}</AppShell.Sidebar>
  <AppShell.Content>{children}</AppShell.Content>
</AppShell>

Composition

AppShell
  AppShell.Rail
  AppShell.Sidebar
  AppShell.Content

Examples

<AppShell>
  <AppShell.Rail brand={<Wordmark />}>
    <a href="/docs">Docs</a>
  </AppShell.Rail>
  <AppShell.Sidebar label="Components">{nav}</AppShell.Sidebar>
  <AppShell.Content>{children}</AppShell.Content>
</AppShell>

<AppShell bare>
  <AppShell.Rail brand={<Wordmark />} />
  <AppShell.Content>{children}</AppShell.Content>
</AppShell>

<AppShell
  style={{ "--echo-shell-rail-h": "64px", "--echo-shell-side-w": "280px" } as React.CSSProperties}
>
  …
</AppShell>

Accessibility

• Real landmarks: the rail is a <header> with a <nav>, the sidebar a <nav> named by label, the content a <main>.
• A skip link to the content comes first on every page. It is not optional.
• embedded (for a shell shown inside another page) drops the skip link and turns the landmarks into plain elements, because a page gets one <main>.
• Put aria-current="page" on the link to the current page; the shell draws the lit rail from it, so the mark and the announcement cannot disagree.
• Focus is scrolled clear of the rail rather than under it (WCAG 2.4.11), from scroll-margin-block-start derived from --echo-shell-rail-h — so retuning the rail moves the offset with it. If you nest an overflow container inside Content, pad the document scrollport too: WebKit does not carry an element’s scroll-margin out through a nested scrollport.

Motion & sound

Motion tokens

--echo-duration-swap

Reduced motion

Only colour changes on hover and selection; nothing moves.

Props

Anti-patterns

• Do not stack the sidebar above the content on a phone. It pushes every screen down by half a viewport and turns the nav into something you scroll past; below 900px the column is removed and the same list belongs in a Sheet behind a rail toggle.
• Never give the rail nav and the sidebar the same landmark name. Two navs called 'navigation' are two identical doors to a screen-reader user.
• Do not set the sidebar's sticky offset by hand. It is derived from --echo-shell-rail-h; hardcoding it leaves a dead band at the top of every sidebar the day the rail's height changes.
• Do not put page content in the Rail. It is sticky and it is a landmark — anything that scrolls away belongs in Content.
• Do not nest a shell inside another without embedded. AppShell.Content IS the page's <main>, and a second one is an axe violation — which is how the docs site's own preview of this component failed the suite.

Changelog

• v0.3.0 · 2026-10-12 · AddedThe drawn device (echo-ui-core, echo-ui-cli, every component that draws its own material). A seed's new render setting is molded (Echo as it has always been: plastic lit by one key light) or drawn: the same parts drawn in the ink, the way a spec sheet draws a key. Every part is outlined at one weight (--echo-line, --echo-line-width), hollow on the body; a raised part stands on a hard ink edge as deep as it rises and travels down it when pressed; a recess is an outline drawn inside; something floating stands on a deeper edge. There's no light, so no gloss, no soft shadow and no glow: what a molded device lights (an LED, the rail, a readout, the focus ring, a fader's knob, a radio's pip) is solid ink, and a low-emphasis action is its label underlined. In black and white (the accent the ink) "on" is solid ink and what's drawn on it inverts: a switch's thumb turns paper, a fader's knob is knocked out with a paper ring. The primary key is the paper key that stands highest, on an ink edge twice as deep as a neutral one's, the way a spec sheet draws its CTA. The accent stays the seed's own colour as a flat fill for what's on (a chosen segment, a checked box, a slider's travel, a switch that's on), so an acid highlighter is acid, not the olive a molded device holds it to; what's drawn on it is the ink, or the body when the accent is too deep for the ink. Pressing, travel, sound, what each material is for and every contrast guarantee are unchanged. npx echo-ui-cli style set render drawn turns it on; a style sets it in its seed; the published style and config schemas describe it, and DESIGN.md says how a drawn device builds. A molded device renders exactly as before: every line is 0px wide there, and each drawn value a component reads (--echo-drawn-fill, -on-fill, -ink, -rule, -glass, -hollow, -decoration) is initial, so it falls back to what the component always drew. HardwareButton's bed is the one new hand-tuned shadow: a drawn key stands on its own edge instead of being drawn in a recess.
• v0.3.0 · 2026-10-12 · ChangedEvery item needs echo-ui-core 0.3.0 (all components). The drawn device, readability past AA and the design tests live in core, and the components that use them are built against it, so each item now declares echo-ui-core >=0.3.0 <0.4.0. Update core with the items: npm install echo-ui-core@^0.3.0 (or your package manager's), then npx echo-ui-cli update. An item whose files didn't change is the same code under a new version; the 0.2.0 files stay published.
• v0.2.0 · 2026-10-04 · AddedThe light device (echo-ui-core, echo-ui-cli). Echo can be light: a pale chassis makes a device molded in light plastic, like a white calculator or a cream radio, and a dark one makes the device Echo has always been. There's no setting and no mode to switch; the chassis decides (devicePolarity, and values.polarity on the theme). On a light device the page is light: its ground, the well, is the body barely set in. Caps get their own ladder, a step lighter than the body with a lit rim that stops short of white, so they keep their bevel; undersides and seams are shaded darker; dim text moves toward the ground by the same step as on a dark device, and reads about 6:1 on it. Screens are paper glass printed in ink, because a glow on a pale body is a smudge. What's lit (an LED, the current rail) is still the accent, held to 3:1 on every ground, so on is brighter than off; the text it prints (a readout, a count, a current tab) and the focus ring are the accent's ink, a step deeper and held to AA, in the new accent-ink role. The primary cap is the same cap as a dark device's, the accent with a light label: its label is the new primary-cap-ink role, and progress cells, loader dots and a meter's fill, the same plastic, read 3:1 on the page. A neutral cap or a slider that fills with it under its own dark label fills with the new pour-* roles, the accent's pale stops. Shadows are drawn at half their weight, in a deep colour of the body's own hue (--echo-cast-ink) instead of black. Every guarantee holds as it does on a dark device, and the contrast sweep now runs on light bodies too. A dark seed makes exactly the theme it did before, and the new roles equal the ones they stand for there. The components that mixed a recess toward black, painted paper in the text colour or lit a pillow of light with it read the theme's new --echo-shade-ink, --echo-paper-stock and --echo-paper-ink instead, with the old value as the fallback, and a reflective screen reads --echo-screen-*; the components that print a lit label read --echo-primary-cap-ink and --echo-accent-ink the same way; every rail is drawn in the glow, and every focus ring, the ring recipes included, in the ink. style use wears a light style now, and style check says which device a style makes. A dark screen tint on a light body is still refused: one text colour can't serve both, and the theme says so.
• v0.2.0 · 2026-10-04 · ChangedComponents whose shadow is a recipe read it by name. 71 shadows in 54 items now say var(--echo-shadow-<name>, <the same shadow>), so they look exactly as they did (every docs page was compared before and after) and follow a theme's recipes. Scope declares the recipes that read the accent again, so a Scope's own colour still reaches its focus rings and glows, and reflective screens do the same for theirs. Shadows that move with their part (a cap's drop as it's pressed) stay in the component.
• v0.2.0 · 2026-10-04 · ChangedComments only, no behaviour change. Comments in the component source used to cite documents, milestones and ticket numbers from Echo's own planning, none of which exist in your project. The citations are gone and the sentences around them stay. Where a comment was only a citation, it now says what it meant. Three development warnings (HardwareButton's engraved/caption checks and StatusDot's missing-label check) also dropped the ticket code at the end of the message. echo-ui diff will show changes in most items; none of them are to code.
• v0.2.0 · 2026-10-04 · ChangedAn item's version is now a function of declared data, not of how the changelog is formatted. The version an item ships under is published once and never rewritten, and it used to be inferred from prose: a regex for a bolded "Breaking" run across the whole unreleased section, and attribution by "does a bullet mention this name in backticks". One breaking entry therefore moved every item that changed that cycle, and an entry explaining that "Menu and Sheet are unchanged here" filed itself as a change to Menu and Sheet — which it really had.
• v0.2.0 · 2026-10-04 · ChangedThe agent brief says Echo has not shipped. llms.txt and the MCP server's instructions led with npx echo-ui-cli init, and that name on npm is a reserved stub with no executable — so a model following the brief wrote an install step that fails with npx's own error. The brief now opens with the caveat, and the docs carry it on every surface that shows a command. One switch (CLI_RELEASED) silences all of them at launch, and a test refuses to let one move without the others. Affects all components only in what the brief says about installing them; no item's props, CSS or rendered semantics change.
• v0.2.0 · 2026-10-04 · ChangedEcho's home is echo-ui.com. The registry, the docs and the packages all move to it from echo.nawwara.studio. Nothing was published under the old host, so no echo.json anywhere points at it and there is nothing to migrate — this is the last release where that is true.
• v0.2.0 · 2026-10-04 · ChangedWeights, line heights, letter-spacing, z-index, border widths and icon sizes come from the theme scales in all components, with the old value as a fallback, so components keep working with echo-ui-core@0.0.1. Strays moved to the nearest step: most by under a pixel; HardwareButton icons are 14/16/20px (were 15/17/19).
• v0.2.0 · 2026-10-04 · FixedOn a phone, a tapped part no longer stays lit (BUG-143). A phone leaves what you tapped under :hover until the next tap, so a table row stayed shaded and a trigger stayed lit after the finger lifted. Hover styles now apply only where there's a pointer that can hover (@media (hover: hover)), in all 23 components that had one. Checked, active and focus styles that shared a rule with them still apply everywhere.
• v0.2.0 · 2026-10-04 · FixedAn AppShell inside a bare one keeps its own sidebar (BUG-117). The bare shell's rule that hides its sidebar reached every shell inside it, so an embedded screen framed on a bare page (a template in a landing page, say) lost its sidebar and its content fell into the sidebar's narrow column. The rule now applies to the bare shell's own sidebar only.
• v0.2.0 · 2026-10-04 · FixedFocus is scrolled clear of the rail, not under it (BUG-33, WCAG 2.4.11 Focus Not Obscured). Tabbing backwards up a long page scrolled the newly focused element to the top of the scrollport, which is behind a rail that is position: sticky; top: 0 — so on a long docs page the thing you had just tabbed to was invisible. echo-app-shell now sets scroll-margin-block-start on .echo-shell__content and its focusables, derived from --echo-shell-rail-h, so a consumer who retunes the rail's height moves the offset with it.
• v0.2.0 · 2026-10-04 · FixedExamples that did not compile. The motion example passed strings to useTactile instead of { motion } phases; the useGsapPresence example omitted the actionsRef cast Base UI needs; the Command keywords example and the AppShell metrics example were not valid code.
• v0.2.0 · 2026-10-04 · FixedContent now reflows into a 320px screen (400% zoom) and survives a doubled browser text size (WCAG 1.4.10, 1.4.4), across all components. Select's 180px floor, NumberField's readout, Segmented and Steps as flex items, EmptyState's grid columns, and Avatar's fixed-pixel disc all gave way; Panel counts its padding inside a width you set (box-sizing: border-box), so a <Panel style={{ width: 220 }}> is now 220px wide overall rather than 260px.
• v0.1.0 · 2026-09-11 · Added45 components across controls, overlays, structure, surfaces, primitives, navigation and texture — including Command (a dot-matrix command palette), AppShell, Sheet (on Base UI's Drawer, with swipe-to-dismiss), AlertDialog, Menu + ContextMenu, Textarea, and Chart.