Busy hours

Keep your app awake around the times you know it will be busy, so the first people to arrive are not the ones who pay for waking it up.

Most of the time your app is asleep. Nobody is using it, so nothing is running, and that is why it costs almost nothing. When someone arrives, it wakes up — which takes a moment. For a personal app, that moment is fine.

Some apps have a moment everyone arrives at once. A channel posts a video and thousands of people open the voting page within minutes. A school sends a newsletter at nine. A club opens sign-ups on Saturday at six. Busy hours keep copies of your app awake around those times, so the first few hundred people get the same fast page as the last.

What you set

• Always — how many copies stay awake around the clock. Zero for most apps. One means the app is never slow for a lone visitor after a quiet afternoon.
• Windows — days and times to keep more copies awake: Saturdays, 17:30 to 21:00, London time, four copies. Up to six windows. Your clock, your timezone; the platform handles the clocks changing.

During a window the database is kept awake too, so the first vote is as quick as the hundredth.

What it costs

This is the one setting that costs money by existing, not by being used, so the price is shown next to it before you turn it on. One copy of a typical app kept awake for an hour is about a cent; keeping the database awake for an hour is nine cents. The Saturday window above — four copies, three and a half hours, every week — comes to about $1.65 a month. Keeping one copy awake permanently is about $6.60 a month.

It is charged on top of your plan, by the hour, and it counts toward your spending limit like everything else — so if your limit is reached, the app pauses rather than the bill growing. Busy hours need a paid plan, because there has to be a card behind a setting that spends.

How to set it

Tell your AI: "Keep my app warm on Saturdays from half five to nine, UK time, with four copies." It will read back the monthly cost and ask you to confirm. Or set it on the app's page in the dashboard.

An overnight window ("22:00 to 02:00") is two windows — one to 23:59 and one from 00:00. The platform will tell you so rather than guess.

When you do not need it

If your busy page is the same for everyone — results, a schedule, a leaderboard that updates every few seconds — ask your AI to let it be cached for a few seconds instead. Then thousands of arrivals become a handful of requests to your app, and it needs no warming at all. That is free, and it is the first thing to try.