Can I mine crypto with HandyCafe?

You have a room of PCs that sit empty every morning and someone has told you they could be earning money while they wait. Can they? Yes, a PC can mine while nobody is sitting at it. Getting that running is the easy part now. Whether it pays is the hard part and for many cafes the answer will be no.

Do the sum first. Install nothing until you have it.

The sum that decides it

I will not give you a profit figure. Payouts change, your tariff is yours and so is your hardware. Anyone showing you a screenshot of earnings is showing you their room on their best day.

Measure one seat instead. Put a plug meter between the wall and the PC, run the mining load for a week and read the kWh. Multiply that by your tariff. Then check what actually arrived in that same week, in your own currency, after every fee.

Now the part people skip. All that power turns into heat and the heat has to leave the room. In a warm shop that means air conditioning. Give the seat a fair share of that bill, the same way the electricity cost article counts it.

Weekly payout - (kWh x tariff) - cooling share = what the seat earned

If the result is thin, remember it has not paid for any wear yet.

You cannot have both on one machine

My usual advice on power bills is to shut idle PCs down. This idea goes the other way.

An idle PC that is off costs nothing. That is the real rival here. Your result has to beat zero, because zero is what a switched-off machine costs you.

Pick one per machine. You can mix them: a few seats stay on to mine, the rest get shut down from the Admin Panel at closing and Wake-on-LAN brings them back when you need them.

What the sum leaves out

Heat and wear come first. Fans and GPUs run hot for hours on the same machines your paying customers need that evening. A fan that dies on a Saturday night takes a paying seat with it.

Antivirus is the next headache. Security software, Windows Defender included, commonly flags miners as unwanted software. You will have to deal with exclusions and every exclusion lowers your guard on a PC that strangers use all day.

Then there is trust. Whatever you install runs on every PC you put it on. Take it only from a source you really trust.

Local rules and commercial electricity contracts differ by country. Check yours before you start. I cannot do that one for you.

What HandyCafe does here

HandyCafe has no miner bundled. It has no pool setup, no hashrate or earnings reporting and no wallet. It takes no cut. It starts a program you choose and it stops that program. Your payout figure has to come from your own miner.

The stopping is the useful part. Each launch goes in its own Windows Job Object. Stopping it ends the process tree, worker children included. If the client crashes, the tree dies too rather than running under the next customer.

When a customer session or admin mode starts, everything is stopped first, before anything else on login. While a session is on or paused, nothing launches. It re-arms when the lock screen returns.

Setting it up on one trial PC

1. Copy the program to the trial PC by hand. File Sync (Settings > File Sync) can put files on a target path on all clients later, if the trial earns that.
2. Open Settings > Clients > Client Tasks and add a task. A task pairs a trigger with an action.
3. Choose the trigger "Idle on the lock screen, stop on input". It needs client 5.2.10 or newer. Older clients never receive it.
4. Choose "Run a program" and enter the path and arguments. If you need a wrapper, "Run script (.bat / .cmd)" takes a script uploaded to the server.
5. Set the idle time. The client enforces a 30 second minimum and checks every 5 seconds. I would go well above the minimum.
6. Set "Mouse tolerance (pixels)". It goes from 0 to 500 and the default is 10.
7. Save. Wait for the program to start, press a key and confirm it stopped. Then start a session and confirm the same.

One thing to know: a task goes to every connected client and there is no setting to send it to one PC. On the other PCs the path does not exist. The launch fails there and their other tasks carry on. That is what keeps the trial to one seat.

There is also a plain "Idle on the lock screen" trigger. It can stop the program at session start but not on input and it runs once per idle stretch. I would not use it for this job.

All of this is Windows only.

Where it falls short

The mouse nudge matters more than you would guess. The client samples input about 4 times a second. Set a low tolerance and a cleaner bumping a desk may stop the program, which then waits for the next idle period. Set a high one and a customer's slight move is ignored until they press a key or click. Those always stop it. Start at the default and change it only if the trial shows a problem.

A miner also needs some time to get going again after each stop. In a room where people walk around and touch things, that adds up.

Then the empty hours. A busy cafe has fewer of them than the owner assumes. Before any trial, look at your actual empty hours for a normal week, not the ones you remember. The same counting decides whether the business pays at all. If the free hours turn out to be few, you may already have your answer.

Your machines, never your customers' time

Run this only on your own machines. Never run it during a paid session. A customer paying for a PC is paying for all of it and HandyCafe stops the program at login for exactly that reason.

Do not hide it either. Tell your staff, because they will hear the fans and wonder.

One PC, one week

Choose one seat that is often empty. Plug in the meter, run it for a week and leave the rest of the room alone until you have the result.

If the number makes you shrug, delete the task and shut that PC down at closing. You found out for the price of a plug meter.