Woopsa is the first fully open-source object-oriented protocol for automation and the Internet of Things
C# C JavaScript HTML Arduino Batchfile CSS
Latest commit aa5742f Jan 31, 2017 @francoisbirling francoisbirling Added property IsLastCommunicationSuccessful and event IsLastCommunic…
…ationSuccessfulChange to WoopsaClientProtocol.

These properties let implement special reactions in the client as soon as a communication problem is detected by the client (server shut down or communication lost)
Note the the event IsLastCommunicationSuccessfulChange is raised from a woopsa thread (concurrent context).



Woopsa is a protocol that's simple, lightweight, free, open-source, web and object-oriented, publish-subscribe, real-time capable and Industry 4.0 ready. It contributes to the revolution of the Internet of Things.

Woopsa allows you to share the complete object model of your application in a way that's similar to OPC-UA. It's based on rock-solid foundations such as HTTP and JSON, which makes it work on the web out-of-the-box. Our mission is to get Woopsa on as many platforms as possible. Today, C# and JavaScript implementations exist, but there are much more to come!

Example JavaScript Client

var woopsa = new WoopsaClient("http://demo.woopsa.org/woopsa", jQuery);
woopsa.read("/Temperature", function(result){
//result = 24.2

Example C# Server

WeatherStation station = new WeatherStation();
WoopsaServer server = new WoopsaServer(station);

station.Temperature = 24.2;

Example node Server

var woopsa = require('woopsa');
var weatherStation = {
    Temperature: 24.2,
    IsRaining: false,
    Sensitivity: 0.5,
    Altitude: 430,
    City: "Geneva",
    Time: new Date(),
    GetWeatherAtDate: function (date){
        var date = new Date(date);
        if ( date.getDay() === 1 )
            return "rainy";
            return "sunny";
    Thermostat: {
        SetPoint: 24.0
var server = new woopsa.Server(weatherStation, {port: 80});

Example Embedded C Server (Arduino, others)

double Temperature;
int Altitude;
float GetAirPressure() {
  return 42.2;


Getting the library

The latest release is part of the git repository, in the well-named Release directory. It contains the .NET and JavaScript versions of the Woopsa library, as well as a few examples to get started!

You can of course also go to the Releases tab of this project, to get version 1.1 here: https://github.com/woopsa-protocol/Woopsa/releases/tag/v1.1

Getting started

Our Getting Started tutorial allows you to get started quickly with Woopsa. It's really easy and we promise you'll be convinced!

Building / Making a release


Run the make-release-windows.bat file. This will

  • Build the .NET library
  • Build the WoopsaDemo server
  • Minify/uglify the JavaScript library
  • Copy all those things in the Release directory

System requirements:

  • Visual Studio Professional 2013 or newer (requires devenv to be in your PATH variable)
  • Uglifyjs (requires nodejs)


A build/release script is coming soon!


Woopsa has been tested and works on:

  • .NET Framework 4.0
  • Mono 4.0+