Secure end-to-end encrypted messaging - from your Desktop or Laptop.
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.
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?
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.
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).
No. The Threema GmbH is currently not interested in working on openMittsu.
No, if you want to send or receive Threema messages automatically, please use the official Threema Gateway API.