# Developer's guide to Mysterium VPN desktop app

This desktop app is built with:
- [Typescript](https://www.typescriptlang.org/) - Typed superset of JavaScript that compiles to plain JavaScript
- [Electron](https://www.electronjs.org/) - Build cross-platform desktop apps with JavaScript, HTML, and CSS
- [node](https://github.com/mysteriumnetwork/node) - Mysterium Node, hereinafter referred to as Node
- [node/supervisor](https://github.com/mysteriumnetwork/node/tree/master/supervisor) - Supervisor: Background service for installing/running Node
- [mysterium-vpn-js](https://github.com/mysteriumnetwork/mysterium-vpn-js) - JS SDK for communicating with Node
- [mobx-react-lite](https://github.com/mobxjs/mobx-react-lite) - Simple, scalable state management

## Supervisor

Supervisor's job is to start Node when necessary and kill it when its job is done. 

Below is a typical communication sequence on a user system where neither Supervisor nor Node is initially running (clean install).

![Myst supervisor](./myst-supervisor.png)

## Node (Tequilapi)

Desktop app communicates to Node's REST API, _aka_ Tequilapi.  
The easiest way to do that is to use [JS SDK](https://github.com/mysteriumnetwork/mysterium-vpn-js).  
Another possible way is to construct HTTP calls by yourself, consulting [documentation](https://tequilapi.mysterium.network/).  

Below is a typical communication sequence between the App and the Node when establishing a VPN connection.

![Node Tequilapi](./node-tequilapi.png)

## Further steps

Fork the repository and start hacking!