What is Majordomo? A personal AI assistant that lives in your house

A majordomo was the person who ran a large household: the one who knew which bills were due, which letters needed an answer, when the roof was last repaired and who the family trusted to fix it. Most of us have never had one. We have had, instead, an inbox, a folder of PDFs, a shared calendar and a nagging feeling that something important is about to lapse.

Majordomo is that person, as software, on a computer in your home.

What it actually does

Give it access to your household's email, documents and calendar and it reads all of it, continuously, and keeps a memory of the household. Then it does the quiet work:

• Triage. It separates what needs you today from what can wait and ignores the noise. Phishing is flagged, not forwarded.
• Catches money leaking out. Duplicate invoices, subscriptions billed under two merchant names, a fixed energy tariff silently ending in eleven days.
• Knows every renewal date. Insurance, passports, leases, MOTs, school deadlines. Each one lands on the calendar months before it matters.
• Drafts with the facts to hand. A reply to the insurer cites the actual policy number and the surveyed rebuild value. A reply to the landscaper cites both invoice numbers.
• Answers questions about your own life. "When did we last service the boiler?" "What did the surveyor say about the roof?" Answered from your documents, not from the internet.

Every morning it leaves a short briefing. Most days there is nothing in it. That is the point.

What it does not do

It does not send anything to a cloud service. There is no Majordomo account, no telemetry, no remote access unless you deliberately grant a support session. The models that read your mail are open-weight models running on a graphics card in your study. If you unplug the network cable it keeps working on everything it already has.

It also does not act without permission on anything that matters. You write the rules: what it may do on its own (file, remind, draft) and what needs your sign-off (send, pay, cancel). The rules are plain text and you can read them.

Why a machine in the house

We get asked why we did not just build an app that talks to a cloud model. Three reasons.

First, the only way to make a privacy promise you cannot break is to never have the data. A household assistant has to read everything: the medical letter, the bank statement, the children's school reports, the will. The right place for that is a disk you can hold.

Second, cost. A cloud assistant that reads everything, all the time, is a bill that grows with your life. On a machine in your home the marginal cost of one more document is a few watts.

Third, permanence. Subscriptions end, companies pivot, terms change. A Majordomo is built from standard hardware and open-weight models, with your data in standard formats. If we vanished tomorrow it would still be running.

What it runs on

The reference build uses a single 96 GB workstation graphics card, which is enough to run models like gpt-oss-120b with your whole household in context. Smaller builds use 32 GB or 48 GB cards and smaller models; larger ones pair two cards. Every machine is assembled to order, burned in for 48 hours and delivered with the software installed. You can configure one here and request a delivery estimate; nothing is charged until you confirm.

Who it is for

Households with more paperwork than time. Families managing a second property, an elderly parent's affairs, a small business, or simply a decade of accumulated accounts. People who would like an assistant with perfect memory and no interest in selling that memory to anyone.

If that sounds like you, the next post explains why we think the assistant should live in the house rather than in a data centre.