How do I invite someone into my circle?

From the circle, generate an invitation code. It looks like FZ-7K4M-92 and comes with a fenzly.app/c/… link you can send in a message.

The invited person types the code into Fenzly, or opens the link. You then receive a request to confirm: nobody enters your circle without your consent. They then choose for themselves what they share.

A code is valid for seven days and about ten uses, then it expires. The server only knows the code and its owner, never the circle it opens.