Cups Messenger for iOS and Android

Start9 Labs
2 min readJun 14, 2020

Start9 Labs is excited to announce the new Cups Messenger apps for iOS and Android, enabling streamlined connectivity to a Cups Server instance. Cups Server is a private, self-hosted, Tor-based, instant messenger, developed by Start9 Labs and made available to Embassy owners as a one-click install.

To use the new mobile app, Embassy owners will need to update their Cups Server instance to ≥ 0.3.1. This is just a click using the Embassy Companion app.

Until now, the only way to connect to your Cups Server was through the Tor Browser or Firefox Browser (with SOCKS5 enabled). This remains possible, but now, thanks to Start9’s own Capacitor Tor Plugin for Ionic, connecting to your Cups Server is barely different than using other messaging apps. The difference? Instead of logging into someone else’s server with a username, you are logging into your own server with a Tor Address.

Privacy without trust. Huzzah!

Unlike other private messengers, with Cups there are no trusted third parties. Even potentially compromised Tor exit nodes are kept out of the loop. Chats over Cups are end-to-end encrypted and routed over Tor to the parties’ own Cups Servers hosted on Tor Hidden Services on physical devices inside their own living rooms.

This is radical.

While such a setup has been possible for quite some time, until now it has never been easy.

Start9 is determined to make real, trustless privacy accessible to even the least technical among us. This is no easy task, and we have a long way to go. But today we celebrate a milestone towards the growing possibility of true digital self-sovereignty with the dramatically improved usability of Cups.


Matt Hill



Start9 Labs

Privacy is a natural human right and must be enforced by technology. We design simple personal servers that run self-hosted, open source applications.