Logbook 01 · 30 September 2026

From a post to a phone in eight days

How a small Brazilian team went from an open challenge to an AI that answers on a phone in airplane mode, and what we learned the day Vitalik Buterin tested it.

This is the first entry in BOAR's logbook: what we built, what we measured, and what surprised us. We'll keep writing it as the app grows.

The idea we stand on

In March 2026, Vitalik Buterin named a family of tools he called sanctuary technology: free, open tools that let people live, work, talk and cooperate without asking anyone's permission, built to hold up under outside pressure. Locally running open-weights AI was on his list, next to Starlink, Signal and Community Notes.

That's the idea behind BOAR. An AI that lives on your phone has no owner who can switch it off, needs no account, and sends your questions to no server. It matters on a plane, on a trail, in a blackout, or anywhere the internet is expensive, watched, or simply not there.

How it started

On 17 September, Vitalik wrote that his killer app would be "a casual info lookup / research tool that's >50% as good as internet + frontier models that can function on a fully offline phone". He said he kept trying every few months, and that the 1B models he could run "break if you try to use them for anything interesting".

The next day the community turned that into a challenge on poidh, a bounty protocol on Ethereum: someone posts a task, anyone can add to the prize, and it goes to whoever delivers. Bounty #31, "Build the Best Offline AI Research App for Android", asked for an app that runs on a phone with up to 12 GB of RAM, fully offline, without Google Play Services, with every line in a public repository. The bounty is independent: its text says Vitalik isn't involved in judging unless he chooses to weigh in.

Ricardo Ferrari, known online as vaipraonde, wrote BOAR with the SOPA collective in Brazil. Version 1.0 shipped on 25 September, eight days after the post, and went in as claim #124.

The day Vitalik tested it

On 26 September, Vitalik posted his tests of the offline apps people had built for the bounty, with four screenshots. One of them is BOAR, answering which signature algorithms resist quantum computers, with its offline sources underneath.

"Definitely getting much better than the one I tried to build myself 2 months ago. But also still much slower and less effective at difficult questions than the models that can run on a laptop."

A minute later he thanked the three builders, @arferrari among them. The post passed 316,000 views, and crypto news sites picked up the story of an AI that works in airplane mode.

We read it as a test, not a verdict: he tested BOAR and credited the builder. The bounty is still open, no claim has been accepted, and the decision is due by 31 October.

What we learned from it

His hardest question was the one we expected least: "Tell me the best vegan restaurants in [city I am currently in]". None of the apps did well on it. A general library can't know what's on your street.

So we built places. The next release carries an offline map of 3.49 million places from OpenStreetMap, found by distance and diet, each with its source. It sits on the roadmap as packs for places, in testing.

What BOAR does today

  • After a one-time download of about 1 GB, it answers with no connection at all.
  • It finds the right passages in a library on the phone, and a small model writes the answer with the sources shown.
  • No account, no ads, and no server that receives your questions.
  • Measured, not promised: 11.4 tokens per second (median) with Qwen2.5-1.5B on a Xiaomi with a Dimensity 8300, and 49,832 Wikipedia articles in a 164 MB pack.
  • Open source under MIT, on Android today, with iPhone in testing.

What we haven't done yet: measure BOAR against internet search plus frontier models, which is the bar the bounty sets.

Built in Brazil, in public

BOAR was built in the open, by a small team in Brazil, against builders from around the world. Every line of it is on GitHub. If you have a phone and a question you'd want answered with no signal, install it and tell us where it falls short.

Sources