ArenaErrorState.prompt.md

Error state with a recovery path (H9). Arena draws the retry button itself from retryLabel (absent renders no retry); onRetry handles the click. secondaryAction is a slot beside it for a consumer-supplied extra control, and code is a diagnostic exposed as a mono chip.

<ArenaErrorState icon="ph-fill ph-warning-octagon" title="Couldn't load the panel"
  message="No connection to the metrics service." code="ERR_UPSTREAM_504"
  retryLabel="Retry" onRetry={reload}
  secondaryAction={<ArenaButton variant="secondary">View logs</ArenaButton>} />

Members, in contract order and under this layer's own names. * marks a required one.

Member	Form	Type	Default	What it is
icon	primitive	string		A Phosphor class name for the danger glyph Arena draws.
title	primitive	string	"Something went wrong"	The headline: what failed.
headingLevel	enum	ArenaHeadingLevel	"h3"	Which rung of the document outline the title takes. Only the element changes: the title's class is the same at every value, so the render is identical and no appearance follows from it. It defaults to h3, the card rung of the title ladder, for the reason an empty state does: a failure fills the body of a region something above it already names. none takes the headline out of the outline, which is what a failure inside a small surface wants, and it is available here because title carries a default rather than being required.
message	primitive	string		A sentence of detail under the title.
code	primitive	string		A diagnostic/support code, shown monospaced.
retryLabel	primitive	string		The label of the retry button Arena draws. Absent renders no retry.
onRetry	event			The retry button was activated.
secondaryAction	slot			An extra control beside the retry (e.g. a link to logs).

Do / Don't

• Always pass retryLabel when a retry could work. An error state with no retry is a dead end the user has to navigate out of.
• icon is a Phosphor class name (a string), never a JSX node; Arena draws the glyph.
• Don't put the raw exception in message. The code chip is where a machine-readable detail goes; the message is for a person.
• Don't use this for a validation failure on a field: that belongs on the field.

The rules of the language hold in the code you write from this page, and no gate reads your application to enforce them. An Arena component is not a styling surface: put no className of your own on it, read every value through its token rather than a raw colour or a bare 16px, and never wrap it in your router's own link. The rest of the rules are in ../../../../../skills/design/SKILL.md.