Rendezvous: private scheduling between sovereign Neutrons (Week 2)

Developers Showcase
1

I helped write the Neutron litepaper, and one idea in it kept nagging at me:
apps inside a personal cloud should be able to compose without handing the
user’s data to a new platform every time they do.

So for Week 1 I built Calendar, and for Week 2 I built Rendezvous on top
of it.

Calendar is a real calendar, not a scheduling mock-up

Calendar has day, week, month, and agenda views; timed and all-day events;
busy/free status; editing, deletion, drag-to-move, and resize; and daily,
weekly, monthly, and yearly recurrence. Events and recurrence rules live in
the owner’s Neutron.

Calendar can stand on its own. The interesting Neutron part begins when another app asks it a narrow question such as “which of these candidate times are available?” Calendar can answer that without sharing event titles, notes, locations, or the rest of the owner’s schedule.

Rendezvous composes two independently owned Calendars

Alice and Bob each have their own Neutron, Calendar, Contacts, and Rendezvous installation. There is no Rendezvous service canister, shared account system, or shared calendar database.

  1. Alice chooses Bob from her local Contacts and explicitly selects the exact
    times she wants to offer. The app does not randomly choose a meeting.
  2. Only those bounded candidate times cross a paid, caller-bound
    Neutron-to-Neutron route.
  3. Bob sees Alice’s locally trusted Contacts name and exact Neutron principal.
    His Calendar privately checks every offered time, and Bob can accept one or counter with an exact alternative.
  4. Holds, revisions, and idempotent commands protect both sides from stale
    availability, double-booking, and uncertain delivery.
  5. After agreement, the same meeting appears in both independently owned
    Calendars. Neither person’s unrelated calendar data was copied to the other.

That is the part I wanted to demonstrate: two apps on two user-owned personal
clouds can produce one useful agreement without inventing a central SaaS
middleman.

There is also an experimental direct-call path. A confirmed participant must
approve a Kernel-owned, revocable, one-time media surface. The Neutrons carry bounded WebRTC signaling, while audio and video flow browser-to-browser. This preview intentionally has no STUN/TURN relay yet, so it is a direct-connect experiment rather than a claim of production-grade Internet conferencing.

Try it or inspect it

The combined branch contains Calendar, Contacts, Rendezvous, the experimental
Kernel media capability, a two-Neutron local configuration, and the end-to-end
test that drives Alice and Bob through the complete workflow.

Please vote in Week 2

Rendezvous is my Week 2 Neutron Hackathon submission. If private scheduling
between sovereign personal clouds feels like a useful demonstration of what
Neutron can do, please open the Season 1 voting page, choose Week 2, and vote for Rendezvous after it clears moderator review.

I would especially value feedback on the cross-Neutron protocol, the privacy
boundary, and whether the Kernel-brokered direct-call experiment is worth
taking toward STUN/TURN support and a production-ready capability. (@jorgenbuilder I know you did a ton of web video on the meme game…would love advice or footguns.)

2

Try Calendar + Rendezvous

Note: Once you have this all set up and have a local instance running you can “call” yourself by using an incognito window.

The rendezvous-hackathon branch is the combined review branch. It includes:

  • Calendar 0.2.0;
  • Contacts 0.3.1;
  • Rendezvous 0.3.0;
  • the experimental Kernel 0.3.13 media capability;
  • a two-node Alice/Bob PocketIC configuration; and
  • the browser test used to verify the submitted workflow.

No additional combined branch is required.

Review the release

The Rendezvous 0.3.0 release
contains all four .neutron archives and the 60-second demo. For an isolated
manual review Neutron, install them in this order:

  1. kernel.v0.3.13.neutron
  2. contacts.v0.3.1.neutron
  3. calendar.v0.2.0.neutron
  4. rendezvous.v0.3.0.neutron

Kernel 0.3.13 is a deliberate experimental Kernel replacement for the
owner-approved ephemeral media surface. Use an isolated review Neutron. The
Rendezvous 0.3.0 package does not install on the upstream 0.3.12 Kernel.

Run the two-Neutron demo locally

Requirements are the same as the Neutron repository, including Node, Bun,
Playwright Chromium, and the local PocketIC toolchain.

git clone https://github.com/skilesare/neutron.git
cd neutron
git checkout rendezvous-hackathon
npm install
npm run provision -- rendezvous-local.ndeploy.json serve

Keep that process running. In another terminal:

npm run provision -- rendezvous-local.ndeploy.json reinstall
npm run provision -- rendezvous-local.ndeploy.json status

The status command prints separate Alice and Bob URLs. The local configuration
installs Contacts, Calendar, and Rendezvous into both Neutrons.

For the most reproducible review, let Playwright create the local Internet
Identity sessions, authorize them, exercise the complete protocol, and verify
the direct browser media path:

npm run test:e2e:rendezvous:fresh

To regenerate the exact submission screenshots:

npm run submission:rendezvous:screenshots

See DEMO.md for a guided manual walkthrough and
SUBMISSION.md for pinned artifact hashes, limitations, and the
release verification commands.