Thanks for the feedback @Stefan_Stoyanov. At this time, making edits to Coda docs (whether published in Edit Mode or unpublished, collaborative team docs) does require a user to sign in to Coda.
Users do have the option for pseudonymous editing (logged-in anonymous editing as shared here: Launched: Logged-In Anonymous Editing), but they do have to log in.
We’ll explore this feedback to see what we can do to open up more editing options down the road!