Most group-coordination tools start the same way: download the app, or create an account, or both. We wanted the opposite. With CollectiveTap, the unit of software is the link. You create one, paste it into a group chat, and it's a live poll, RSVP, signup sheet, or expense split — for everyone, with zero sign-up on either side.
Here's the architecture that makes that possible, and the three decisions that mattered most.
Decision 1: No accounts — authorization lives in the URL
There are no users in our database, because there are no user accounts. Every link carries a signed capability token that encodes what the holder is allowed to do:
// Simplified: a capability is an HMAC-signed payload in the URL
