Finally: actual code being written (Alpha release soon)

Just a quick summary of our last posts and developments: We settled on Rust as a programming language and we wanted to start implementation with the Threema Gateway API to avoid any conflict with the company behind Threema. After making these decisions, we spent a lot of time learning Rust and exploring the related SDKs. However we were very disappointed, when we finally found out, that the Threema Gateway API does not support group chats – at least that's what the Threema support told us.

Undocumented group messages in Threema Gateway API

So we were ready to switch to the client-based approach, when we finally got in contact with a very nice Threema employee who let us know, that Gateway API does indeed support group messages, but it's an undocumented feature, and we need to build a lot of custom logic on top of received group messages (Group messages in Threema are just multiple messages sent by a client to all other members of the group).

First running version: Alpha release soon

With this heplful advice, we were ready to actually write some code, and that's what we did. We have a first running bridge version that supports bidirectional group text messages between Threema and Matrix. All our work is happening on the development branch. We have a little bit more cleaning up to do, but we are confident to release a first alpha version, which can be tested by others, within the first days of July 2022. It will still miss some features, but it will already support simple text messages in both directions.

Also, since we've been in contact with a very helpful Threema employee (privately, outside of their work hours), we officially introduced ourselves and the project to Threema via E-Mail, and we're hoping to hear back from them soon.