A studio for local-first software · Est. 2026

Prime Ideal

a studio by JZ

Software built from first principles. Small, essential, provable — and your data never leaves your machine.

In ring theory, a prime ideal is an irreducible building block: the structure everything else is constructed from, and the thing that stays put when the ring is divided by it. That's how we build — a few essential pieces, rigorously proven, quietly kept.

DEF · RING THEORY · P ⊂ R
Products — 01 shipped to beta
Product 01 · Private beta

iVesta

A perimenopause gut health companion. Your lab reports are read by a model running entirely on your own Mac — analysis, food plan, daily check-in, weekly digest. No account, no cloud, no telemetry. Your health stays home.

ENTER →
02

Next instrument

In the forge — announced when it's ready, not before.

Principles — invariant across every product
01

Local-first, absolutely

If a product doesn't need your data to leave your device, it never will. Privacy is architecture, not a policy page.

02

Accessible by design

Measured contrast, generous type, forgiving targets. Every screen is audited before it ships — WCAG numbers, not vibes.

03

Evidence over hype

Claims cite their source. Models synthesize; rules decide anything safety-critical. We verify, then we verify again.

04

First principles

Fewer moving parts, each one understood. Software you can trust is software someone actually read.

Specimen band — 02 slides under observation
• Slide 01Mag 2.17× • Live
Cellular Visions (i) #1Lindsay Kokoska
• Slide 02Mag 1.44× • Live
Cellular Visions (i) #2Lindsay Kokoska
•Your data stays home•Local-first · always
"Your health data stays home" is no longer a slogan, it's the specification of everything this studio builds. The instruments built by this studio observe, remember, and advise without your most sensitive data ever leaving your Mac. The proof is in the architecture: zero network calls, by construction.

© 2026 Prime Ideal · all data shown on this site is fictional · contact

built by JZ, with love 🤍