@mikkel-ol/tunnelmole/dist/src/messages/client-message.d.ts

Tunnelmole, an open source ngrok alternative. Instant public URLs for any http/https based application. Available as a command line application or as an NPM dependency for your code. Stable and maintained. Good test coverage. Works behind firewalls

export default interface ClientMessage {
    type: string;
    logLevel?: string;
    message: string;
}