Castalia Institute · Founding batch

An instrument, not another screen.

Astrolabe is a round pocket companion for homes that already use Castalia and Mynah: time at a glance, tonight’s moon, your transits — and when you have a question, you hold one button and listen for the answer.

About the size of a pocket watch · Round 1.75″ display · Wi‑Fi · Built for daily glances, not scrolling

10:42 Saturday · May

Showing: Moon

Illustration — product photos coming with the founding shipment.

How you use it

No feed. No app grid. You look, you swipe once in a while, and when you need Castalia you talk to the instrument.

1

Glance

Wake the round face for time, moon phase, or today’s transit wheel — made for a two- second look, not a session.

2

Ask

Hold the side button and ask aloud — about tonight’s sky, your chart, or the day ahead. The watch records, thinks, and answers through Castalia’s voice service (the same family as Mynah).

3

Listen

Tap the other button to hear the last reply again — or your agenda when there’s nothing to replay. Sound comes from the built-in speaker.

What’s on the dial

Swipe around the bezel. Each face is one job. Astrolabe ships with the full set — time, sky, music status, focus timer, and sign-in for your Castalia account.

Time & rhythm

Classic analog and digital clocks tuned to the round screen.

Sky

Moon illumination disk and a live transit wheel with spoken readings.

Home

Optional Spotify glance, focus countdown for deep work, and QR pairing to your Castalia login.

Made for Castalia households

Mynah is the portrait phone at the center of the home. Astrolabe is the round satellite — pocketable, glanceable, and quiet between questions. Sign in once; your account works on the watch for voice answers.

Astrolabe and LunaSay

Same beautiful round hardware. Two ways we flash and tune it for the founding batch.

Astrolabe

The complete instrument — every launch face, for families who want time, sky, music, and focus in one swipe cycle.

  • Full face set at boot
  • Best default if you’re new to Castalia hardware

LunaSay

The chart-first edition — moon and transits up front, tuned prompts for sky language, quieter if you don’t need Spotify or focus timers on your wrist.

  • Same founding price
  • Same firmware tree — flash either image later

lunasay.castalia.institute →

Founding batch

We’re building a small first run on the bench — hand-tested units for people who want the instrument early and can tolerate fast-moving firmware.

Astrolabe · complete edition

$349

USD · assembled · USB-C · quick-start card

  • All launch faces and voice answers through Castalia
  • Open firmware — inspect and flash from GitHub
  • Founding support while features mature
  • Firmware updates as sky accuracy improves
Email us to request a spot

We reply with availability, deposit, and ship window. No charge from this link alone.

Common questions

Do I need a Mynah phone?

No. Astrolabe talks to Castalia over Wi‑Fi on its own. Mynah is the reference companion in the same household — closer integration is on the roadmap.

Is this a smartwatch?

It’s closer to a pocket instrument: round display, two buttons, no app store, no notifications feed. You buy it for time, sky, and short voice turns with Castalia.

When does it ship?

Founding units ship in waves through 2026. We confirm your window by email after you request a spot.

For builders

Hardware & repo

Reference board: Waveshare ESP32-S3 Touch AMOLED 1.75C class (466×466 round AMOLED). Firmware and build instructions: github.com/CastaliaInstitute/astrolabe.

Chart accuracy in early firmware

V0 uses on-device approximations today; server-side ephemeris is in progress. Founders receive updates as accuracy improves — no extra hardware required.