injectRequestSize

injectRequestSize(): RequestSizeFn

type RequestSizeFn = (size: { width?: number; height?: number }) => Promise<void>;

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

export class PollWidget {
  private readonly requestSize = injectRequestSize();

  showAll() {
    this.requestSize({ height: 640 });
  }
}

Omit a dimension to leave it unchanged.

The host decides

The call is a request. The host can refuse it, or it can give a different size. Read the real value from injectLayout, because maxHeight holds what you actually have.

Measure, then ask

Pair the call with a ResizeObserver on your root element, so you ask for the height your content needs.

const observer = new ResizeObserver(([entry]) => {
  this.requestSize({ height: entry.contentRect.height });
});

Do not call it on every frame. A host applies a size change asynchronously, therefore a tight loop of requests is wasted work.

Host support

Host	Behavior
Apps SDK	No operation. The call writes a warning and resolves.
MCP Apps	Supported.

An Apps SDK host controls the size of the iframe itself. There is no equivalent call.

Because the promise resolves either way, a call is safe on the two hosts. Design the view so it also works at the size the host gives you.

Related

• injectLayout
• injectDisplayMode
• Host support