`<wmcp-menu>`

A menu button. Its exposed action is the first parameterized one in the library: where button and dialog expose no-argument actions, the menu's tool takes which item — an enum of the item values — so the agent picks exactly as a person would.

The popup uses the native Popover API (top layer, light-dismiss, Escape, and anchored positioning), with arrow-key roving focus over the items. Selecting one — by click, keyboard, or agent — fires a composed select event and closes the menu. A menu dispatches actions; it does not hold a value.

<wmcp-menu name="row_action" label="Row actions" expose>
  <option value="duplicate">Duplicate</option>
  <option value="archive">Archive</option>
  <option value="delete">Delete</option>
</wmcp-menu>

Items

Items come from declarative <option> children — the same authoring as <wmcp-select>, works with no build — or from the items property for JS / framework callers:

document.querySelector('wmcp-menu').items = [
  { value: 'duplicate', label: 'Duplicate' },
  { value: 'delete', label: 'Delete', disabled: true },
];

When items is non-empty it takes precedence over the children. Disabled items render but can't be selected, and are left out of the tool's enum.

Element attributes

Attribute	Type	Default	Description
`label`	`string`	—	Trigger text and the menu's accessible name.
`items`	`WmcpMenuItem[]`	`[]`	Items as data (property only); overrides `<option>` children.
`open`	`boolean`	`false`	Whether the popup is open (reflected; driven by the trigger).
`name`	`string`	—	Identifier used for the default tool name (`select_<name>`).
`expose`	`boolean`	`false`	Register a WebMCP tool that selects an item.
`tool-name`	`string`	—	Override the generated tool name.
`tool-description`	`string`	—	Override the generated tool description.

Selecting fires select with detail: { value, label }.

Tool shape

The tool takes one argument — the item to pick, constrained to the enabled values:

{
  "type": "object",
  "properties": {
    "item": { "type": "string", "enum": ["duplicate", "archive", "delete"] }
  },
  "required": ["item"]
}

The enum tracks the live item set: change items and the tool re-registers with the new values. Selecting an unknown or disabled item returns an error result.

Theming

Trigger and popup are themed through --menu-* custom properties, defaulting to the shadcn palette:

:root {
  --menu-bg: var(--popover);
  --menu-item-bg-hover: var(--accent);
  --menu-radius: 0.75rem;
}

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