Busy hours
Keeps 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. On paid plans, paid from Uarpie credit.
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.
While a copy wakes, Uarpie usually asks your app for its home page once, so that work is done before the first person's page. That request carries the header x-uarpie-platform: 1. If your home page calls a paid service, such as an AI model, that can be one more call each time a copy wakes.
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 1.2 cents; keeping the database awake for an hour is 12 cents. The Saturday window above — four copies, three and a half hours, every week — comes to about $2.57 a month. Keeping one copy awake permanently is about $8.76 a month.
No plan includes busy hours. They are paid from your Uarpie credit by the hour, only while they are on, and they count toward your spending limit. So they need three things: a paid plan, credit above $0, and a spending limit above $0.
If the credit runs out, or the month's use above your plan reaches your spending limit, your apps pause. Nothing is deleted. They come back at the start of the next month, or straight away when you add credit or raise the limit.
How to set it
Tell your AI: "Keep my app warm on Saturdays from half five to nine, UK time, with four copies." It tells you what that costs a month, and asks before turning it on. Or open the app's page in the dashboard and choose Keep it awake at busy times, which shows the same price.
With no credit, turning busy hours on is refused with CREDIT_NEEDED and nothing changes. Add credit on the billing page, then set them again.
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.
For a Java app
A Java app is slow to start, so for it, instant start is usually the better buy: every new copy starts in about a second, at any time of day, for less than keeping one copy awake. The two cannot be on together.
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.