Questions estates ask

The gates keep working. Gate phones still check QR passes and residents' offline codes, and gate controllers decide everything on the box. Entries are uploaded as soon as the connection is back, and controllers at different gates share what they let in over the estate's own network.

No. Where the estate turns on USSD, residents can dial a short code to book a visitor for today, get a delivery code or hear their codes. A household member with a smartphone can also book for the home.

No. A visitor only needs the six-digit code or the QR the resident sends them, by any messaging app, SMS or WhatsApp.

The estate. Online payments settle straight into the estate's bank account through the payment gateway. Petra Platform never holds residents' money.

None to start: a guard with an Android phone runs a gate. For unmanned lanes, a gate controller (a Raspberry Pi or small computer) drives the barrier and reads keypads, QR scanners, tags and number-plate cameras.

The estate office adds them with their phone number, or they ask to join with the estate's join code and the office approves the request. Landlords and tenants add their own household.

Each estate only sees its own data. Visitors' details are kept only as long as the estate's retention setting allows, and every message sent to a visitor links to a privacy notice. Staff support access is read-only, time-limited and recorded in the estate's audit log.

An estate can be live in a day: add the homes and residents (or share the join code), set up the gate phones, and residents install the app. Gate controllers take a little longer to install.