Invites — the second example

What a share link cannot do: inviting a known person directly, with no link and nothing to forward, through a mailbox only the two of you can compute. Built on the notes example (../notes-app/notes.js) plus @microtoll/mailbox; invites.js is everything this example adds (about 150 lines).

Run it

cd examples/invite-app
docker compose up

Then open http://localhost:8089, in two browsers or a normal and a private window, as Ada and Bea:

1. Both: Boot, Sign up, type a name.
2. Ada: New note, share by link; Bea pastes the link, Open link, then join as member.
3. Both: remember people on that note. Each now holds the other's keys from the note's own roster — nothing was exchanged with the server.
4. Ada: New note, then invite Bea directly. Bea's page is woken by the live watch and collects the invitation; the note appears with read access. Nobody made a link.
5. Bea: open it — her app tells Ada it was seen. Ada: invitations shows "collected, seen".
6. Ada: another note, invite Bea directly, then take back before Bea's page collects it. Bea's next collection finds nothing.

docker compose down -v throws the database away.

What the server learns, honestly

• Mailbox labels: a 32-byte value per pair per month, written under by one connection and polled by another. It cannot compute a label (that needs one of the two private keys), attribute one, or pair the writer and the reader without both keys.
• Which labels a routing key polls and watches — one per contact per month, two months deep — so it learns how many people an account knows, not who.
• That a routing key sent a drop today (the daily counter), and each drop's expiry.
• Everything the notes example lists, since the notes are the same.

It does not learn a name, a note's key, who invited whom, or that an invitation was seen (the acknowledgement is a drop like any other).

Where things are

• invites.js — contacts from a roster, a direct invitation, collection, the acknowledgement on opening, withdrawal, the live watch.
• page.js, index.html — the page.
• test/invites.test.mjs — the story above, driven from Node against a real server and database (node scripts/test-db.mjs up, then npm test).