Questions about Roast Harness
What it is, who it's for, what it costs, which roasters it supports, how to get it, and how to roast with it safely.
What is Roast Harness?
Roast Harness is a free desktop app for roasting coffee. Tell it the cup you want, and its AI agent, Aden, writes a roast program for your machine, rehearses it on a simulator and runs it on your roaster, with someone staying at the machine. It's made by Nizami Coffee.
Who is it for?
Cafés and small shops that want to roast their own coffee, and people roasting at home. It doesn't take a roasting specialist. It takes someone who won't walk away from the machine.
How do I download it?
Roast Harness will be a free download for macOS at roast.nizamicoffee.com/download. The first public build isn't out yet. Windows and Linux are coming soon.
How much does it cost?
The app is free. The AI and its live services are pay-as-you-go, from prepaid credits, with no subscription. The smallest top-up is $5. By our estimate from early use, a café roasting 40 pounds a week spends about $18 a month.
Which coffee roasters does it work with?
Roast Harness supports 70 roasters from 36 makers. It improves with use, learning your machine and set-up, and it compares historical and community roast physics to predict maintenance issues.
Do I need to know how to roast?
No. Aden writes the program and runs the roast, so you don't need to hire a specialist or spend a year learning. You load the beans, stay with the machine, drop the batch when it calls the drop, and taste the result.
Does the AI control the machine by itself?
It works the heat, the air and the drum through the roast, and it can start the preheat when you ask it to. You pour in the beans, which starts the roast, you drop the batch, and you can take over at any time.
Can I leave it running?
No. Someone stays at the machine from the preheat through the whole roast, with a hand near its power switch, ready to stop the roast and take over. Never run a roast unattended. Software is not a safety device. Your protection against a stuck element, a stalled fan or a bean fire is the machine's own cut-outs and interlocks, and those must be present and working.
Does it get better over time?
Yes. Every roast you save gives it more to work with on your machine and your coffee. It improves with use, learning your machine and set-up, and it compares historical and community roast physics to predict maintenance issues.
How much can a café save?
By our estimate, a café using 40 pounds a week and paying $12.85 a pound keeps about $11,600 a year once it's running, with a $4,841 set-up. These are estimates, and yours will differ.
Which computers does it run on?
macOS. Windows and Linux are coming soon. Adding it to Claude, ChatGPT, DeepSeek Harness, Qwen and Kimi is coming soon.
Where is it available?
Roast Harness isn't currently offered in mainland China, the European Economic Area, the United Kingdom or Switzerland. We may change this list as we open new markets.
Who makes it?
Nizami Coffee (Nizami, Inc.), a Delaware corporation founded by Jeff Wang.
Next: How it works