custom plugin

gaea-editor has many built-in plug-ins, and it's also the best demo:

UI plugins

import Editor from 'gaea-editor';
import MyPlugin from './my-plugin';

export default () => <Editor plugins={[MyPlugin]} />;

use Connect decorator from 'dob-react', then you can access all built-in stores and actions. Demo.
gaea-editor has some built-in position, and plugins can register positions by using ApplicationAction.loadPluginByPosition(position: string).