Attachment — accessibility

Keyboard

The name is a real <button> (ghost compact Button) when onOpen is set, so Tab reaches it and Enter or Space opens the preview; without onOpen it is a plain, non-interactive span — nothing promises an interaction that does not exist.
Every action (download, save, remove) is a real IconButton: Tab reaches each one in order, Enter or Space activates it. Download is a real <a href> (IconButton href), so it also gets middle-click / "open in new tab" / "save link as".
busy sets disabled on every IconButton action, which removes each from the tab order (native disabled) — the name button stays reachable so the user can still open the preview while a file uploads.
auto renders no interactive elements at all beyond the static name text.

The chip's own title attribute (defaults to the file name) gives a native tooltip on hover/focus for the whole chip; it carries no ARIA role of its own — the accessible structure comes entirely from its children (a button, a link, zero or more icon buttons).
Every action button gets aria-label="<action>: <file name>" (e.g. "Stáhnout: Smlouva_o_dílo_2026-09.pdf"), not just the bare verb — in a list of several attachments a screen reader user tabbing through icon buttons would otherwise hear "Stáhnout" repeated with no way to tell which file each one belongs to.
The name button, when present, gets the same pattern: aria-label="<open label>: <file name>".
The type glyph (<Icon>) is decorative; the file name text carries the meaning.

All interactive pieces are native <button>/<a>, so the foundation ring from ds.css applies with no overrides in attachment.css.
busy does not move focus; a focused action that becomes disabled while busy loses its ring like any other disabled control — the surrounding chip does not trap or manage focus for this.

Tokens shared with Item list and other components that use the same muted-text pattern (packages/ui/src/tokens/tokens.css):

File name in .acrm-att-static / the ghost compact button label: --fg on the chip's --surface-100 — well above AA in both themes.
Size .acrm-att-sz and the auto chip's static text use --fg-muted / --fg-secondary — --fg-muted is 2.85:1 in light theme, 3.63:1 in dark, below AA for text (the same deliberate cost as everywhere else this token is used for a secondary or tertiary read).
The auto chip's dashed border is --border-strong, a non-text boundary, not read as content.
Icon button actions inherit Icon button's own contrast figures (rest-state glyph 3.93:1 light / 6.20:1 dark — meets the non-text minimum only).

Size and the auto label sit at or below the muted-text contrast limit, same as every other secondary/tertiary text in the DS — not specific to Attachment.
No live region announces that busy finished — a screen reader user has to re-focus the chip to learn an upload completed.
The chip's title tooltip is not reachable on touch, same limit as Icon button; the visible name text is the only guaranteed way to read a truncated file name on a phone.