Halvern: meeting notes that never leave your machine

In one sentence

Halvern is a Mac app that records meetings, transcribes them and writes the summary entirely on your own computer: no account, no upload and no per-minute billing.

The problem

Every meeting tool that writes notes for you does it by sending your meetings to someone else's servers. For client calls, salary conversations or anything under NDA that is the wrong trade, and most people are never asked to make it consciously.

The idea

The constraint is the product: nothing leaves the machine unless the user points it somewhere. Instead of a privacy statement you have to trust, the privacy promise names the places in the code where you can check it. A default build sends nothing and cannot be made to send anything without being rebuilt.

What I designed and decided

• Onboarding asks which language your meetings are in, and the answer picks the transcription engine. Before that, one engine was fixed, and people speaking Japanese, Chinese or Turkish got useless transcripts with no warning.
• The summary model is chosen in plain sight during onboarding. When a default was downloaded silently, a bad choice could not be fixed, because the user did not know there had been a choice.
• Updates are checked once at start-up, not on a timer, because a regular check would reveal when the user is in meetings.
• The interface is 4 full screens without a sidebar, and deliberately without transparency effects, because contrast cannot be guaranteed on a see-through wall, and a wall that looks transparent contradicts a product whose promise is a closed door.
• The landing page has no analytics, because a tracking beacon would make its first sentence false.

How AI is used

In the product, transcription and summaries run on local models; external providers are off until the user configures them. Building it, I worked with AI agents: 179 of 310 commits were co-written with Claude. Before choosing the summary model I ran a comparison with the decision rules set before the measurement: 5 languages, 4 models, 40 generations. It also exposed 3 defects in the measuring tool itself.

Where it stands

Halvern is a fork of Meetily, an open-source meeting recorder under the MIT licence, and says so openly; I rebuilt the interface and the brand, added language handling and removed the paid upgrade funnel. A signed pre-release for Macs with Apple Silicon, with a public repository under the MIT licence and a download at halvern.io. Windows and Linux builds compile in CI, but nobody has recorded a meeting on them yet. It has no paying users and is not meant to: it is free.

Why it belongs in the portfolio

Halvern is a product decision taken all the way through: one promise, privacy, shapes the onboarding, the update policy, the interface and even the landing page. It is also proof that I ship, not only design: a signed, notarised app that updates itself.

My role

I designed and built Halvern on top of Meetily, working with AI agents.