Parameters

useTableRowExpansion() takes one config object. Wrap it in a getter or a ref so the panels follow the current expanded set: useTableRowExpansion(() => ({ ... })).

Name	Type	Default	Description
expandedKeys	ReadonlySet<string>	—	Required. Set of currently-expanded row keys. Consumer-owned.
onToggle	(key: string) => void	—	Required. Called with a row key when its expansion is toggled, by the chevron or by the context-menu action.
getRowKey	(item: T) => string	—	Required. Derive a stable unique key from a row item.
renderExpanded	(item: T) => VNodeChild	—	Required. Render the detail content shown in a full-width panel below the row when it is expanded. Receives the row item.
getIsItemExpandable	(item: T) => boolean	—	Control which rows are expandable. Non-expandable rows show no chevron, no context-menu action, and never render a panel. Defaults to all rows expandable.
panelVariant	'muted' | 'transparent'	'transparent'	Background behind the detail panel. 'transparent' paints nothing: the panel is the row's continuation and takes whatever surface the table sits on, so a Card shows through and a striped table's zebra reads on unchanged. 'muted' washes it, marking it as commentary rather than another row of data — reach for it in a bare table with no card, dividers or striping, where nothing else makes that distinction. The wash is a low-alpha near-black, so it is close to invisible over a dark card: 'muted' is largely a light-theme effect.
hasRowClickExpansion	boolean	false	Toggle a row by clicking anywhere on it, not only on its chevron. A pointer-only convenience layered over the chevron, which stays the accessible control for keyboard and assistive tech. Clicks on interactive cell content (buttons, links, form controls) or on a text selection do not toggle, and non-expandable rows stay inert.

Returns

useTableRowExpansion() returns one TablePlugin<T>. Pass it to Table in plugins. The plugin fills three fields of the plugin contract:

Name	Type	Description
transformColumns	(columns: TableColumn<T>[]) => TableColumn<T>[]	Prepends the __expansion column with the chevron.
rowPatch	(row: T, index: number, columnCount: number) => TableRowPatch | null	Adds the expand action to the row's context menu, the optional whole-row click, and the panel when the row is open. Returns null for a row that is not expandable.
cellPatch	(input: TableCellPatchInput<T>) => TableCellPatch | null	Marks the chevron cells with the astryx-table__expansion class so they keep their 40px width.

TableRowPatch

Name	Type	Description
attrs	Record<string, string | undefined>	data-expanded is set on an open row.
class	string	astryx-table__clickable when hasRowClickExpansion is on.
onClick	(event: MouseEvent) => void	Toggles the row, unless the click landed on an interactive element or on a text selection.
menu	TableRowMenuItem[]	One item that expands or collapses the row. Its label is localized.
panel	TablePanelPatch	The detail panel below the row. Carries variant and render, and is only present while the row is open.