There's no way to see what API call is using resources, but you can view the per service breakdown on what each service is using by resource type, you can view that data from within the usage page of your account.

@brody thank you, any suggestion how to optimise it and reduce the expenses? With no changes, the billing is three times higher so if I am unable to get some insight.. for a particular service… how can I trust it/optimize it

so if I am unable to get some insight.. for a particular service

But you can? you are able to view the accumulative values for cpu, mem, egress, and disk.

At a high level, write efficient code and your app will use less resources, but there's not too much else we can help with in that regard.

@brody well what is good code? It does what I want it to do but your product is charging for something without revealing all details - I am sure you have the details under the hood. So it would be good to know and be transparent

and any explanation why the bill is three times higher than previous months and still is much higher this month estimate than previous? I didn't change the code, neither number of visitors in my project increased. Did you guys increase prices?

Not very happy with the transparency here. Ok it's using resources but how/which. You could as well artificially increase it or have bug in your code if there is no transparency on your side.

This page outlines how your bill is derived from resource usage, with as much transparency as any other hosting platform:
https://docs.railway.app/reference/pricing#usage-pricing

There is also a calculator you can use to take the guesswork out:
https://railway.app/pricing#usage-estimation

If you see usage you didn't expect, it's your responsibility to have visibility into your own services to see why. You wouldn't go buy twice as much bread at the store then ask why your receipt shows twice the cost.