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MCP_MODAL

The modal service for MCP Apps hosts, with an isOpen signal and a close method.

An MCP Apps host renders a modal in your frame. Therefore the view itself must know that it is in a modal, and it must be able to close it. MCP_MODAL gives you both.

import { MCP_MODAL } from "ng-mcp-ui/web";

export class PollWidget {
  private readonly modal = inject(MCP_MODAL);

  readonly isModal = this.modal.isOpen;

  dismiss() {
    this.modal.close();
  }
}

McpModal

Member Type Purpose
isOpen Signal<boolean> true while the host reports the modal display mode.
close () => void Dismisses the modal.

close() flips the local display state back to inline. It is synchronous, and it sends no message to the host, because the modal is rendered in your frame.

close() is not the same as two neighbouring calls.

Call Effect
MCP_MODAL.close() Closes the modal. The view stays.
injectRequestClose Removes the whole view.
injectDisplayMode setDisplayMode("inline") Messages the host to change the mode.

The tokens and providers

Symbol Purpose
MCP_MODAL The token that holds the resolved modal.
MCP_MODAL_ENABLED true only on an MCP Apps host.
provideMcpModal() Provides both tokens.
createMcpModal(adaptor, enabled) The non-DI form.

provideMcpUi() appends provideMcpModal() for you. Add it yourself only when you build your own provider set.

On other hosts

On an Apps SDK host, and during SSR, the feature is disabled. MCP_MODAL then resolves to a no-op modal: isOpen is always false, and close() does nothing.

Therefore you can inject and call it without a host test. The Apps SDK host owns its own modal chrome, so there is nothing for the view to close.

The Escape key

When the feature is enabled, the service attaches a keydown listener, and Escape closes the modal. The listener is removed on teardown. A host with no DOM, for example during SSR, skips it.