Agents that work while you sleep need a Mac that never does.
A used 2019 iMac (or a Mac mini M4) turned into a silent background worker that runs Claude Code agents, runs the jobs you give it, and never sleeps. This is the exact setup guide for the box that runs mine: 72 GB of RAM, 2.6 TB free, five days of uptime at the last check, no server bill. Full config, the 25-step clone checklist, the rakes we stepped on, and the parts list.
What's inside the guide
- The always-on pmset config, line by line: sleep 0, disksleep 0, displaysleep 15, autorestart 1, powernap 0. The display sleeps; the machine never does.
- The launchd boot chain: power returns, FileVault unlock, Redis, a node entry point (not a bash wrapper, so TCC grants stick), secrets pulled from LastPass at run time, the bridge, then the timer jobs.
- The security posture: disk encrypted, nothing listening for inbound logins, Full Disk Access on one stable node binary, no secrets on disk.
- The 25-step clone checklist and the nine rakes already stepped on.
This exact box has run Brad's agents 24/7 with five-day uptime and is the reference machine for Optimus members.
The parts list
A renewed 2019 27" 5K iMac with the 3.7 GHz 6-core i5, a 64 GB (2 x 32 GB) DDR4-2666 kit that brings it to 72 GB, a Seagate Portable 2 TB or 5 TB backup drive, an optional Elgato Stream Deck MK.2, or a Mac mini M4 as the modern alternative. Affiliate links, we may earn a commission.
Why a Mac?
Why a Mac and not Windows?
launchd and a Unix userland make unattended automation boring, which is what you want. macOS TCC gives a granted process access to iMessage, Contacts and Messages that nothing else can touch. It runs the same Claude Code binary you use at the desk. A 2019 iMac is silent at idle for years. And used 2019 iMacs are cheap.
Why not a Chromebook or iPad?
They can't run the CLI or a real process manager. No shell, no launchd, no long-running node process. The agent needs all three.
Why not Linux?
Linux can do the automation part fine. What it can't do is iMessage, Contacts, or any of the Apple apps your business already lives in. If your customers text you, the box has to be a Mac.
Intel 2019 iMac vs Mac mini M4?
Both work. The Intel iMac has no MLX and no local models, but it takes 72 GB of RAM and has a screen you can log into after a power cut. The M4 is faster and sips power. The guide is written on Intel; the M4 steps are the same minus the RAM upgrade, since M4 memory isn't user-upgradeable.
Does it need to stay logged in?
Yes. All the workers run as LaunchAgents under one interactive login. FileVault plus a power loss lands at the unlock screen until someone types the password. The guide covers the trade-off and the pmset settings that make it a rare event.
How much does it cost to run?
Electricity only. No servers to rent; the database it talks to is one you already run. The machine is a used iMac on a desk, not a server you rent, and the Claude Code subscription you already pay for is the brain.
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