Swimlanes.io is a free webapp for making sequence diagrams. You simply edit the text on the left and the diagram is updated in real time. You can download your sequence diagrams as images or distribute with a link.
title: After Client -> Server: `anonymous user` Login (user+password) Server -> Client : token `anonymous user` note: **at this point in time** the _session_ is still an Anonymous session, but session checked for authentication. Client -> Server: `anonymous user` token + MFA code Server -> Client : Navigate to page `logged in user`