What the platform enforces

When you book a session, the rules you saw at booking are applied by the platform itself — not by the organizer's goodwill. The organizer chooses the values; the platform applies them the same way for everyone.

DOC v1 · applies to every booking on Sessionata (dev)

The platform enforces

When booking opens and closes. A session accepts bookings from its opening moment until its closing one, and not a minute either side. Both are computed from the class's own settings against that session's date.
The commitment point, and its charge. Release a spot before it and you owe nothing. After it the booking stands, and a no-show is charged exactly as attendance would have been — on whatever payment form the booking was made with.
The grace undo, and that check-in ends it. A booking can still be undone during its grace even after the commitment point has passed. Once you have checked in at the door, the grace is over and the spot counts as used — and you are told that, rather than being told the cancellation window closed when it had not.
Capacity limits. A session stops taking bookings at the number of spots it has. A full session tells you it is full rather than taking a booking it cannot hold.
Punch and membership redemption. Whether your punch card or membership covers a session is worked out by the platform from what the organizer published, and the punch or credit is drawn by the platform when you book. If that cannot be worked out at all, nothing is charged and nothing is drawn.
Settlement timing. The money for a session is drawn at one moment, a set number of minutes after that session starts — the same delay for everyone booked into it.
That these terms are shown before you book. A class's own rules — when booking opens and closes, its commitment point, its grace, its prices — are generated from its settings and shown beside the session you are about to book. They are not typed by anyone, so they cannot say something different from what is applied.

The organizer controls and promises

The values of those rules. How far ahead booking opens, how long the grace runs, where the commitment point falls, what a session costs, how many people fit — all of it is the organizer's to set, within what the platform will enforce.
That sessions happen as scheduled. A session on the calendar is the organizer's undertaking to run it.
Instruction and facility. Who teaches, what is taught, and the place it happens in.
Refunds beyond the rules. Anything outside what is set out above — a goodwill refund, a credit for a session you missed — is between you and the organizer.
Waivers, insurance and local legal requirements. Any agreement you are asked to sign, any cover the organizer carries, and anything the law where they operate requires of them, is theirs.

Good habits

If something matters to you — the undo window, the price, the cutoff — read it on the class page before you book rather than after. It is there precisely because it is generated rather than promised.
For anything in the second list, ask the organizer. They are the ones who can answer it, and the ones it binds.

Did you know? The same rules an organizer edits are the rules that refuse a late cancellation, release a punch, or draw a no-show charge — there is no second copy to drift out of step. That is why what you are shown before you book and what happens afterwards cannot disagree.