Sparehand

Your other computers are sitting idle. Put them to work.

Sparehand turns the old laptop, the gaming PC or the spare Mac you already own into helpers for your main Mac. Slow jobs such as running tests, building an app or running an AI model go to whichever machine is free. You keep working, and your Mac stays quick.

Try it free for 14 days Pricing

No card needed for the trial. For Mac (macOS 14 or newer, Apple silicon or Intel). What you need.

$ sparehand run npm test
[sparehand] → gaming-pc (CPU 3% busy, 81% memory free)
Tests: 1284 passed, 1284 total

How it works

  1. Add your other computers

    Run one command on each, check that both screens show the same code, and you are done. Macs, Windows PCs and Linux machines all work.

  2. Run slow jobs as usual

    Put sparehand run in front of a command, or let your AI coding assistant do it for you. Sparehand picks the machine that is least busy and has room.

  3. Get the result back

    The output appears on your Mac exactly as if it had run there. If every machine is busy or switched off, the job simply runs on your Mac instead.

Your machines

One screen shows every computer, how hard it is working and whether it has room. This is an example setup.

  • DeskYour main MacIdle

    Free for your own work.

  • macbook-airSpare MacWorking

    Running your tests.

  • gaming-pcWindows PCWorking

    Running a local AI model on its graphics card.

  • nasHome serverOffline

    Asleep. Skipped, or woken up when needed.

What you get

Faster tests

Split one big test run across all your machines at once. A test suite that took 2 min 33 s on one computer finished in 55 s on three.

Works with AI coding assistants

One command lets Claude Code send its tests and checks to your spare machines by itself. Other assistants can follow a short rule you paste in.

Local AI, one address

Run AI models on the machines with a graphics card. Everything on your Mac reaches them at one address, localhost:11434.

Polite to whoever is using them

A machine only takes a job when it has room. If someone starts a game or the machine runs low on memory, the job moves elsewhere. You can pause any machine.

Wakes and sleeps machines

Sleeping computers are woken when needed and kept awake during long jobs.

See it from your phone

A menu-bar app on your Mac, plus a dashboard for your phone or tablet with jobs, history and screens.

Files and services

Show a spare machine's folder in your Finder, or reach a service running on it as if it were on your Mac.

And, in beta

Crew hands a coding task to several AI agents under one Master. Studio turns a brief into a finished video. Members use your models on credits. Cloud machines at Runpod, AWS, Azure or Google Cloud join when your own are busy. Included in the licence; marked Beta while they settle.

Private by design

Everything runs on your own computers. There is no cloud service and no tracking. Secret .env files are never copied. Read how.

Questions

What counts as a spare computer?

Any Mac, Windows PC (with WSL2, a free Microsoft feature) or Linux machine, at home or a server anywhere. It needs SSH, rsync and git. Plain jobs leave nothing running on it: the project copy sits in a folder and the machine is idle between jobs. Two optional features do install a service there: sparehand ai install adds the Ollama model server (started with the machine, for that user only), and Studio's setup adds ComfyUI and its models. sparehand remove NAME --clean takes all of it off again. The uninstall page lists everything.

Do I need to be technical?

You should be comfortable opening Terminal and running a command. The app guides you through adding each machine step by step.

Does it copy my secrets?

No. Files that git ignores stay on your Mac, and .env files are never copied to your other computers.

What if every machine is busy or off?

The job runs on your own Mac, or waits briefly for a free machine if you ask it to.

Does it send my data anywhere?

Not to me. Files and jobs go only between your own machines, over SSH, and there is no tracking. The app checks your licence with Lemon Squeezy, our seller, looks for updates once a day, and reads the list of AI models from ollama.com (you can turn that off). Features such as Studio, Crew, cloud machines and cloud AI providers talk to the outside services you connect to them yourself, and only once you add a key. The privacy policy lists every one.

What is in beta?

The core (running jobs on your machines, split test runs, the Claude Code hook, local AI, wake and sleep, file sharing, the dashboard) is what the trial and the licence are for. Crew (AI coding agents with a Master), Studio (video production), members (letting other people use your dashboard on credits), cloud machines (Runpod, AWS, Azure, Google Cloud) and cloud AI providers are in beta: they work and are included, but they may change, and the docs say so on each of their pages.

What does it cost?

$29 a year, after a 14-day free trial that needs no card. Every update is included. Pricing details.

Ready to try it?

Download the free trial See pricing