Secure end-to-end encrypted messaging - from your Desktop or Laptop.

What is openMittsu?

openMittsu is a cross-platform open source implementation and desktop client for the Threema Messenger App. It has been created by reverse engineering the Threema mobile App and studying the publication from Jan Ahrens as well as the Threema Gateway.

Can I use the same ID for openMittsu and Threema?

The protocol Threema uses doesn't provide multi-device functionality (yet) which means you can't be connected with more than one device using the same ID simultaneously. However, if you disconnect your phone before connecting with openMittsu, you can use the same Threema ID for your phone and openMittsu. Please beware that you will only receive messages on one device. Alternatively, consult the Threema FAQ-answer on this topic: Can I install Threema on multiple devices?

Can I generate a Threema ID using openMittsu?

No, please use the Threema app you purchased for generating an ID. You can use Threema on a second user on your phone or in an emulator if you need to as long as you have a legally purchased Threema app.

Does the Threema GmbH allow this project?

Yes, Threema tolerates the openMittsu project. However, if openMittsu will get abused, Threema may change their decision. Don't worry, your ID won't get banned just for using openMittsu (if you are using openMittsu just for instant messaging like you do with the Threema app).

Is the Threema GmbH involved in the development?

No. The Threema GmbH is currently not interested in working on openMittsu.

Can I use openMittsu for automated messages?

No, if you want to send or receive Threema messages automatically, please use the official Threema Gateway API.

What's the difference between openMittsu and Threema Web?

While Threema Web relies on a working connection to your Android smartphone running Threema, openMittsu acts as a standalone client. You can use openMittsu without a phone. Also, openMittsu is a native application, not a JavaScript / browser based web application.