Events

A workshop is announced in a group chat, people sign up by replying, the places are counted by hand — and then more turn up than the room holds and somebody is left standing at the door. What is needed is a registration page with a number of places that cannot be exceeded however many people press the button at once, and a list on the day.

Who it is for

• Workshop and exhibition organisers
• Associations and community centres
• Marketing teams

• The last place cannot be taken twice

  A unique index on the place number and a constraint that no number may exceed the event’s capacity, above a SERIALIZABLE transaction and a retry for whoever lost the race. Ten registrations in the same instant for one place: one succeeds, and nine are told the event is full.

• Cancelling gives the place straight back

  A cancelled registration lets go of its place number at once and the next person takes that very place — the lowest free number first, so no gap is left to push the next number past capacity — while its row stays on the record.

• A public page that names nobody

  An address of 16 random bytes carrying the title, the time, the place, how many places are left and the name of the business inviting — and not one registrant’s name. Changing the address kills the old one at once.

• Nothing here charges anybody

  If a place has a price, what is owed is written down in whole minor units in the event’s own currency and frozen at the moment of registering. There is no payment gateway, nothing is collected, nothing is posted to the ledger, and a free event is the default.

• A list at the door

  Registrations from the public page and from the desk on one list, and a mark of attendance stamped from the server’s clock that does not give up the place. A capacity of zero means no limit: places left reads as unknown rather than as none.