# The useful stack: what actually runs here

**What it is:** the real tool list behind one small business that runs on agents, with what each
piece costs and what it replaced. Not a "top 50 AI tools" post. Every line below is something
that earns its keep on a normal week. If a tool is not here, it is because it did not survive.

**Shown at:** AI Open House, by Colton Mulligan.

## The short version

Four things do almost all of the work: a paid Claude plan, a paid ChatGPT plan, one cheap
always-on computer, and plain Markdown files. Everything else is a convenience.

## The stack, piece by piece

| What | What it does here | Rough cost |
|------|-------------------|------------|
| Claude, Max plan | The main agent. Chat on the desktop app, real work in Claude Code. | From $100 a month |
| ChatGPT, Plus plan | A second opinion and a worker for chores, run through the Codex CLI. | $20 a month |
| An always-on Mac mini | Runs the long jobs, the schedules and the backups so a laptop lid can close. | Hardware you may already own |
| Plain Markdown files, in git | The business's memory: standing instructions, decisions, inventories, runbooks. | $0 |
| A private GitHub repo | Carries that memory between machines. | $0 |
| Cloudflare Pages | Every site and tool ships here. Free hosting, custom domains, instant rollbacks. | $0, plus $5 a month if you add Workers |
| Cloudflare R2 | Big files a site needs to serve (video, archives), without an S3 bill. | Pennies at this size |
| A registrar you do not hate | Domains, bought from the command line. | About $11 a year each |
| Backblaze Personal Backup | Offsite backup for the always-on machine and every USB drive hanging off it. | About $99 a year |
| A meeting recorder | Captures calls so an agent can file the notes and the action items. | $0 to about $20 a month |
| Dictation (Wispr Flow) | Talking to an agent is three times faster than typing to one. | About $15 a month |
| An outline tool (WorkFlowy) | One place for lists an agent can read and write. | About $9 a month |
| A password manager | The one place credentials live. Agents never get the vault. | About $5 a month |
| Two battery backups | Keeps the machine and the internet up through a flicker. See the UPS recipe in this library. | About $130 and about $60, one time |

## The four rules that matter more than the tools

1. **Plain text wins.** Context lives in Markdown files in git, not inside one vendor's product.
   That is what lets you switch models, switch apps, or run two agents on the same business.
2. **One job, one owner.** Every schedule and every service runs on exactly one machine. Two
   machines running the same job is how you get two half-finished results and no error message.
3. **Buy the boring hardware first.** An always-on computer and a battery backup fix more real
   problems than the next subscription will.
4. **A tool you have to remember is a tool you will stop using.** If it matters, it is a standing
   instruction the agent reads at the start of every session, or it is a schedule. Not a habit.

## The prompt

Hand this to your agent to get your own version of this page, instead of copying mine:

```text
Walk my setup and write me a one-page stack list in Markdown.

Look at: what subscriptions I pay for, what is installed on this machine, what scheduled jobs
exist, where my files actually live, and what hosting or domains I own.

For each one, give me three columns: what it is, what it actually does for me in a normal week,
and what it costs per month or year. Sort it so the four or five things doing most of the work
are at the top.

Then tell me, in plain sentences:
- anything I am paying for that nothing has used in the last 30 days
- any job that two different machines or services are both trying to do
- anything that would break permanently if this one machine died tonight

Do not recommend new tools. Only describe what is already here.
```

## Stack card

```text
WHAT IT DOES:     Lists the tools actually running one agent-run business, with real costs
AI / MODEL:       Claude (desktop app and Claude Code), plus ChatGPT through the Codex CLI
STACK:            Markdown in git, an always-on Mac mini, Cloudflare Pages and R2
WHERE IT LIVES:   this recipe
COST TO RUN:      The four load-bearing pieces run about $120 a month plus hardware
TIME SAVED:       Mostly money: the audit prompt above usually finds a dead subscription
TIER SHARED:      recipe plus the audit prompt
```

Prices move. Check the vendor's own page before you budget off this one.

Built by Colton: https://builtbycolton.com

From the AI Open House free library: https://aiopenhouse.co/guests/#library