The app is free. You pay for the AI as you use it.
You buy prepaid credits as you need them, and there's no subscription. The AI and its live services draw on them as you use them.
What it comes to
By our estimate from early use, a café roasting 40 pounds a week spends about $18 a month on the AI and its live services.
That's what Roast Harness costs, not what roasting costs. A café still needs a roaster, green coffee and someone at the machine. By our estimate that café keeps about $11,600 a year against buying roasted, once it's running. Run your own numbers.
What each thing costs
| What | Rate |
|---|---|
| A turn with the AI agentOur estimate from early use, rounded up. | about $0.005 |
| Writing a new coffee's roast and estimating its cupOur estimate, at 25 turns. | about $0.13 |
| The live forecast during a roastAlways on while a roast runs. | $0.006 a minute |
| Fitting a saved roast to your machine and coffeeEach time you save a roast. | $0.01 a roast |
Rates as of November 2026. The app shows the current rates, and we give notice before changing them for future use.
How credits work
You buy prepaid credits in US dollars, under Settings → Credits in the app. There's no subscription.
- The smallest top-up is $5.
- Paid credits don't expire while your account is open.
- Auto-reload is off unless you turn it on.
- Credits are non-refundable, except where the law requires otherwise.
The Terms of Service have the full terms.
Next: Download Roast Harness