Session gives you a random Session ID instead of a phone number. Messages go through an onion-routed network of community nodes, so there is no central account database of who messaged whom. Clients are open source. There are phone and desktop apps.
Onion routing costs time. Big files are limited. Calls exist and they are not Signal’s calls. Session is not Tor, and it is not SimpleX. You still have a long-term ID that contacts use. If you post that ID everywhere, you built a public name. The privacy is the lack of a phone number and the lack of a single server holding the social graph.
Use it when you will not give a carrier number to a chat app. getsession.org
Treat the Session ID like a user name you cannot rotate casually. Posting it on a public profile ties every later message to that post. Blind a device you lose, from another device, if the app still lets you. Large attachments and flaky calls are the tax. If you need reliable voice, Session is the wrong primary phone. It is the right second channel when a number is the problem.
