streamdeck-typescript/src/interfaces/events/send/send-to-plugin.event.ts

This library will help you build elgato stream deck plugins in typescript

/**
 * Data send from the sendToPlugin event
 * @category Event Data
 */
export interface SendToPluginEvent {
    action: string;
    event: 'sendToPlugin';
    context: string;
    payload: any;
}