The assumption
Every operating system assumes one occupant.
The scheduler, the session model, the permission system, the login manager — all of it was designed around a single human at a keyboard. That assumption held for fifty years. It is quietly breaking, because a second kind of occupant has moved in.
What changed
An agent is not a program in the sense the OS understands. A program is brief; an agent runs for hours. A program waits to be told; an agent acts on its own initiative. A program's appetite is predictable; an agent will hold gigabytes and a GPU for an afternoon.
And an agent will route around any obstacle it can reason about. That is not a flaw — it is the whole reason it is useful. But it means please don't is not a boundary, and a denylist in a config file is not a boundary either. Both live in the same space the agent is thinking in.
The opinion
A machine should have two planes.
Not two machines, and not a container you remember to use. Two planes on the same hardware, with separate resource budgets, separate lifetimes, and separate privileges.
Human plane
desktop · browser · editor · games
its own memory budget · dies with your session
Agent plane
long-running agents · builds · emulators
its own memory budget · survives your logout
Your desktop dying should not take a six-hour agent run with it. An agent going wide should not make your desktop unusable. And the line between them belongs where the agent has no standing to argue — cgroups, Landlock, seccomp, eBPF — not in a file it can read and reason about.
Why a distribution
Because this cannot be bolted on. Slice layout, security policy, what survives logout, what the login manager does, what every agent tool defaults to on a fresh install — those are a distribution's decisions, not a package's. A tool can ask nicely. Only the system can decide.
Why gaming laptops first
They are the cheapest capable agent workstations in existence — 32 GB and a real GPU for mid-range desktop money, already sitting on millions of desks. And on Linux nobody serves them properly: hybrid graphics, suspend, fan curves, RGB, the discrete GPU that half-wakes.
UmamiOS targets that hardware first, deliberately, because the machines people already own are where this has to work.
The name
Umami is the savoury fifth taste — the one people cannot name but immediately miss when it is absent. A reasonable ambition for an operating system.