Metzo - Digital Door and QR Availability PWA - Productivity Project

Metzo is a mobile-first progressive web app that gives every person a Digital Door: a permanent public page, a permanent handle and a permanent QR code that visitors can scan to see whether you are free right now and ask to come in.

It replaces the handwritten note taped to a cabin door. A doctor, professor, designer or accountant prints one QR code once, sticks it on the door, and from then on anyone standing outside can see the current status and knock without phoning, messaging or waiting around.

The Digital Door

Every host gets a clean public profile at their own handle. Visitors need no account at all.

Permanent handle that can never be changed, so printed material never expires
Display name, designation, organisation, bio and location shown to visitors
Current availability status with an optional message and usual hours
Knock, request a meeting, save the profile or share it, straight from the page
An explicit privacy note: no GPS, no live location, no last seen

Permanent QR Code

The QR code resolves to the handle URL, so it stays valid for the life of the account.

View, download as PNG or SVG, print, share or copy the link
A print-ready card layout with name, designation, organisation and a scan prompt
A built-in scanner for opening someone else's Metzo door
Guidance for sticking it on a cabin door, a reception desk stand or an email signature

Availability Status

Status is set manually and deliberately — nothing is inferred from sensors or activity.

Available, Available Soon, Not Available, By Appointment and Do Not Disturb
Optional presets for In Meeting, Busy and In Class, plus a fully custom label
A free-text status message and optional available-from and available-to hours
Some statuses keep knocking open while others pause it entirely

Digital Knock

A visitor standing outside the door submits their name and purpose, with contact details optional. The host sees it immediately and answers with one tap.

Responses: Come In, Wait 5 Min, Wait 10 Min, Come Later or Can't Meet
Near-real-time delivery through AJAX polling, with no WebSocket requirement
Browser notifications for incoming knocks
Knock inbox filtered by pending, today, all and sent
Visitor details stored only against the interaction, never as a user record

Meetings, Messages And Saved Doors

Meeting requests for hosts who work strictly by appointment
Direct messages between a visitor and a host with unread counts
Saved profiles that store only the pair of user references, never a copy of host data
Search by name or handle, which a host can opt out of
Activity history of knocks, responses and meetings

Host Dashboard

One screen answers the only questions a host has during the day: am I marked available, who is waiting, and where is my QR code.

Current status with a one-tap change
Digital door link and QR code with copy and share
Today at a glance: knocks today, pending knocks, unread messages, pending meetings, times saved
Recent knocks with inline response buttons
Quick actions for QR, status, messages, meetings and search

Accounts And Privacy

Registration by email with a one-time code, then password and permanent handle selection
Reserved handles protect system routes from being claimed
JWT authentication, hashed passwords and CSRF protection on writes
Prepared statements, upload validation, rate limiting and secure headers
Privacy settings control searchability and what a visitor may see
Location, last seen and history are never collected, so they cannot leak

Admin Panel

A separate admin login with its own account table covers users, knocks, meetings, messages, analytics, reserved handles, system settings and logs.

Progressive Web App

Metzo installs to the home screen with a web manifest and service worker, is built mobile-first with a bottom navigation bar, and runs on ordinary shared hosting with no build step, no framework and no WebSocket server.