A box you own. RAM you can add later.

The Brains Box

You killed the $96/mo VPS. The better answer is a small computer you buy once and own outright: a cheap business mini-PC with real RAM slots, running headless Linux as the cortextOS brains. The Mac stays the hands. The catch is honest: a 2026 RAM price spike makes "cheap plus 32GB" harder than it was six months ago, so the winning move is a used micro with open slots you fill over time.

$170 to $330 $170 best case for a refurb Dell OptiPlex already at 32GB. About $330 the reliable everyday path: a business micro at 16GB plus one stick, or a new box that ships 32GB. One-time buy, no monthly bill, real RAM slots.

Brains you own, hands on the Mac

The box: brains

  • Runs the whole cortextOS daemon: agent reasoning sessions, the message bus, ChromaDB vector store, task state, crons, coordination.
  • Headless Linux (Ubuntu). No screen, no keyboard. Sits on a shelf, sips power, stays on 24/7.
  • Real RAM slots, so you add memory as the fleet grows instead of buying a whole new machine.

The Mac: hands

  • Browser automation against ChiroHD, SKED, GHL, and the other no-API surfaces that must run on a real Mac.
  • Local UI actions, Telegram desktop, iPhone mirroring, anything Mac-only.
  • Stops being both brain and hands, which is what makes it choke today.
One honest architecture note. cortextOS has no built-in multi-host mode today. So the box does not "share the load" with the Mac. It runs the entire daemon, and the Mac becomes a pure browser operator reached over a secure tunnel. That is a clean one-time migration, not a split-brain setup.
Auth rule the migration must respect. Only one machine may run the Claude agents on our account, because they share one credential and a second machine refreshing it triggers a lockout race (we hit exactly this on June 20). That rule is satisfied here: the agents move entirely to the box, and the Mac runs zero Claude agents afterward. The box becomes the auth authority. One migration detail to handle: Linux stores the credential in a file rather than the Mac keychain, so the credential-keeper we are building gets a small Linux variant.

What the brains box actually needs

Claude and Codex run their models in the cloud. The local box is not doing AI inference, it is running Node.js CLI sessions plus a vector database. That keeps the spec modest and cheap.

RAM target 32 GB

Comfortable room for 8 to 10 long-running agent sessions plus ChromaDB. 16GB runs it lean; 32GB is the headroom number. Add more later via the open slot.

Storage NVMe M.2

ChromaDB does fast random reads. A 512GB or 1TB NVMe drive gives years of runway. Most of these micros ship with one and have a free slot.

CPU 4 to 8 core

Any recent business chip (Intel i5/i7 8th gen and up, or Ryzen) is plenty. This is coordination work, not heavy compute.

The 2026 RAM spike, stated plainly

There is a real AI-driven memory shortage in 2026. RAM prices have jumped hard, which is why "sub-$300 with 32GB already installed" is tough right now. The lever that beats it: buy a box with DDR4 slots. DDR4 is the older, cheaper memory, and used business micros use it. You pay less per gigabyte and you add it gradually.

DDR5 32GB SODIMM kit $350 to $440

What new mini-PCs use. $14.12 per gigabyte right now. A kit briefly spiked past $800 in May 2026.

DDR4 32GB SODIMM kit $200 to $250

What used business micros use. $9.08 per gigabyte, roughly $150 to $200 cheaper than DDR5 for the same 32GB. This is the cost lever. A single 16GB stick is $85 to $120.

The picks

Best price

Dell OptiPlex 7080 Micro

The cheapest confirmed route. i5-10500T, two DDR4 SODIMM slots (max 64GB), NVMe M.2. A Micro Center refurb ships already at 32GB and 512GB.

$169.99 refurb at 32GB / 512GB (Micro Center, stock-dependent). 16GB configs $200 to $230 at Best Buy.

Safest supply

HP EliteDesk 800 G5 Mini

The safe sweet spot. i5-9500T or i7, two SODIMM slots (max 64GB DDR4), two NVMe M.2 slots. Huge refurb supply, well documented, tool-free to open.

$245 refurb at i5 / 16GB / 256GB. A 32GB config runs about $339.

Solid alt

Lenovo ThinkCentre M90q

Compact, two DDR4 slots, NVMe (Gen 2 has two M.2). Cleanest BIOS of the three. Buy on price, it sometimes runs higher used.

$170 to $250 refurb at i5 / 16GB / 256GB on eBay.

Three ways to 32GB, by total cost

Bars show one-time total to reach 32GB. Lower is better. The Mac mini line is the new-Apple-hardware comparison from the earlier research, shown only to anchor how much a dedicated box saves.

RouteWhat you buyRAM pathTotal at 32GB
A. Refurb already at 32GB Dell OptiPlex 7080 Micro, 32GB / 512GB Nothing to add, ships at 32GB ~$170
B. Business micro plus one stick HP EliteDesk 800 G5 at 16GB Add one 16GB DDR4 stick ($85 to $120) ~$330
C. New box, done day one WVX Ryzen 6600H, new with warranty Ships with 32GB DDR5 ~$330
D. Low-RAM micro plus full kit 8GB micro plus a 32GB DDR4 kit Worst value, the spike taxes the kit $350 to $425

How we actually move

The one-time migration

  • Install Ubuntu headless on the box, plus Docker and the 1Password CLI for secrets.
  • Cold-copy ChromaDB, the repo, and agent state from the Mac. The live fleet keeps running untouched during this.
  • Bring the daemon up on the box in shadow mode, verify it matches the Mac, then cut over in a quiet overnight window.
  • Keep the Mac as cold standby for a couple of days. Roll back by repointing if anything regresses.

What needs you

  • Buy the box (account plus payment). I cannot purchase hardware, so I hand you the exact listing to click.
  • That is the only gate. Everything after, Ubuntu setup, migration, tunnel, cutover, the fleet runs on a single go.
  • One-time spend, not recurring. No monthly VPS bill, and you own the hardware.

Sources and notes

The pick: if you can land the Micro Center refurb, the Dell OptiPlex 7080 Micro at $170 already holds 32GB and 512GB, which is the whole job for the price of a nice dinner out. If it is out of stock, buy the new WVX at $330 or the HP EliteDesk at $245 and add one $85 to $120 stick. Either way it is a one-time spend under your budget, and the slots stay open for 64GB later.
RAM spike: Tom's Hardware RAM Price Index 2026, WCCFTech shortage outlook to Q4 2027, Honeybee SODIMM analysis. DRAM contract prices rose 90 to 95 percent in Q1 2026 as makers shifted capacity to AI memory.
Used micros: Dell OptiPlex 7080 Micro 32GB refurb, Micro Center $169.99, HP EliteDesk 800 G5 Mini refurb, Newegg, Lenovo M90q Gen 2 spec.
New mini-PCs: WVX Ryzen 6600H 32GB DDR5 (SODIMM confirmation), Minisforum UM870 Slim, Beelink SER8 (ServeTheHome teardown).
Prior research: VPS pick (killed, too expensive) and Mac mini RAM analysis in Sage's notes. The Mac mini path was ruled out because Apple memory is soldered and cannot be upgraded, which fails the "add RAM slots later" requirement.
Architecture grounding: cortextOS state is file-based and single-host; the box runs the whole daemon, confirmed against the codebase.