What are workspace APIs?

import { NodeJsSyncHost } from '@angular-devkit/core/node';
import { workspaces } from '@angular-devkit/core';

async function addBuildTargetOption() {
  const host = workspaces.createWorkspaceHost(new NodeJsSyncHost());
  const workspace = await workspaces.readWorkspace('path/to/workspace/directory/', host);

  const project = workspace.projects.get('my-app');
  if (!project) {
    throw new Error('my-app does not exist');
  }

  const buildTarget = project.targets.get('build');
  if (!buildTarget) {
    throw new Error('build target does not exist');
  }

  buildTarget.options.optimization = true;

  await workspaces.writeWorkspace(workspace, host);
}

addBuildTargetOption();