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Popover

Base UI Popover (anchoring, focus, dismiss, a11y) skinned as an Echo panel. Same useGsapPresence bridge as Modal (summon enter, GSAP exit before unmount), sound.select on open.

Feel A small glass panel anchored to its button, holding more than a tooltip can.

Preview

Or let the agent fetch it: get_component("popover") on the Echo MCP server.

Installation

npx echo-ui-cli add popover

First time? Run npx echo-ui-cli init once — it sets the project up, and add refuses to run before it.

At a glance

Version
0.3.0
Weight
742 B · 68.7 KB with what it imports · 517 B of CSS (minified and gzipped; React not counted)
Needs
gsap, @base-ui/react
Keyboard
Focus moves into the popup when it opens. Escape or a click outside closes it and returns focus to the trigger.
Reduced motion
It fades in and out without moving.
Sound
select when it opens.

Usage

tsx
import { HardwareButton } from "@/echo/hardware-button";
import { Popover } from "@/echo/popover";

<Popover trigger={<HardwareButton>Info</HardwareButton>} title="Details">
  <p>Anchored content.</p>
</Popover>

Composition

Popover

Examples

Basic

A trigger with a titled panel.

tsx
<Popover trigger={<HardwareButton>Info</HardwareButton>} title="Details">
  <p>Anchored content.</p>
</Popover>

Controlled

Close it from inside: pass `open` and `onOpenChange`, and it still animates out.

tsx
<Popover
  open={open}
  onOpenChange={setOpen}
  trigger={<HardwareButton>Filters</HardwareButton>}
  title="Filters"
>
  <HardwareButton onClick={() => setOpen(false)}>Apply</HardwareButton>
</Popover>

Accessibility

  • Base UI Popover: the trigger is a button that toggles a dialog-like popup, named by title.
  • Focus moves into the popup when it opens. Escape or a click outside closes it and returns focus to the trigger.
  • Unlike a Tooltip it is reachable by touch and can hold interactive content.

Tested against WCAG 2.2 AA on every release:

  • axe — No axe violations, in the component's own gallery and on its page.
  • keyboard — Every action is reachable and operable from the keyboard alone.
  • focus-visible — Focus is visible on every focusable part, in normal and forced-colors mode.
  • forced-colors — State stays visible when the look's colours are replaced by the system's.
  • target-size — Every target's real hit area is at least 24×24px, at every density.
  • reflow — Content reflows into 320px and survives a doubled text size.

Not covered: screen-reader: not yet verified by a person. Everything above is a machine check; a person has not yet driven this component with a screen reader.

Motion & sound

Motion tokens
summon
Reduced motion
It fades in and out without moving.
Sound
select when it opens.

Props

Popover props
PropTypeDefault
triggerWhat opens the popover. An element becomes the trigger itself; text is wrapped in a plain trigger.ReactNode
titleHeading inside the popover, and its accessible name.ReactNode
sideWhich side of its trigger it opens on: bottom (the default), top, left or right."top" | "right" | "bottom" | "left""bottom"
alignWhere along that side it lines up with the trigger: start, center (the default) or end."start" | "center" | "end""center"
sideOffsetThe gap between the trigger and the panel, in px. Default 8.number8
containerWhere the popup mounts; defaults to <body>. Pass an element inside a scoped theme so the popup wears that theme, not the :root one.unknown
openOpen, controlled. Leave it out and the trigger opens and closes it.boolean
onOpenChangeCalled with true or false as it opens or closes: from its trigger, Escape, a press outside, or a change to open.function
initialFocusA ref to what takes focus as it opens (a date picker's chosen day). Default: the first thing in it that can take focus.unknown
anchorA ref to what it's placed against: a whole field rather than the key in it. Default: its trigger.unknown
aria-labelNames the popup when it has no title, so a screen reader says what it is and not only "dialog".string

Anti-patterns

  • Do not add a CSS transition to the popup — GSAP owns its transform/opacity.
  • Do not use a Popover where a Tooltip fits (hover hints) — Popover takes focus and traps dismissal.
  • The package is @base-ui/react, not @base-ui-components/react.

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 · AddedPopover can be opened and closed from outside (echo-popover). open and onOpenChange make it controlled, and a close from outside still animates out. initialFocus says what takes focus as it opens, anchor places it against something other than its trigger (a whole field rather than the key in it), and aria-label names a popup that has no title.
  • 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 · ChangedBreaking: Echo's public API names Echo's own types, not Base UI's. Eleven items put a @base-ui/react type straight into a signature you write against — BaseSwitch.Root.ChangeEventDetails on a change handler, ComponentProps<typeof BaseSelect.Portal>["container"] on a portal target. That made Echo's API a downstream of Base UI's internals: an upstream rename would have been a breaking Echo release triggered by somebody else's refactor.
  • 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 · FixedProps the docs did not list. HardwareButton (icon, trailingIcon, target, rel), Modal (trigger, title, description, footer), Popover (trigger, title), Tooltip (trigger), Slider (value, onValueChange, aria-label, aria-labelledby), NumberField (onValueChange), SoundProvider (backend) and Textured (dither, noise) now appear in the prop tables, llms-full.txt and the MCP server.
  • v0.2.0 · 2026-10-04 · FixedPopups opened inside a dialog appeared behind it. A Select, Popover, Tooltip or Menu inside a Modal or Sheet opened under the dialog's backdrop. They now stack above it.
  • v0.2.0 · 2026-10-04 · FixedA trigger element from a server component was wrapped in a second button on a Next.js dev server, for Modal, AlertDialog, Popover and Tooltip. It now becomes the trigger itself.
  • 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.