About ESI API

[umutyerebakmaz]

Hello, I started developing a 3rd party web application. Improved killreport and handles competition between players in a more innovative way. My question is:

Is there a limit on requests made to ESI APIs? I already use the cache mechanism in my own application. In other words, the same API request on the same page does not trigger a second time. The same applies to your image server. How should I handle this issue? Could I be banned if you consider that I took all the images in the game from ESI and the image server instead of keeping them by name and keeping them within my own organization? Thank you in advance.

[umutyerebakmaz]

I use image server all the time for my FE, no issues
https://esi.evetech.net/ defines cache, for example This route is cached for up to 1200 secondsand you should respect it
overall I am doing:
some endpoints are on demand and I respect the cache duration before firing new request
some endpoints are on loop and trigger automatically on cache + 2 minutes interval
I never fire more than 1 request per 30ms, so at most I am doing 30 requests per second instead of just bursting all the calls

following these, I get like errors / timeouts maybe 2-3 times per 2-3 days...

even rebuilding the whole database by getting 37k items, I have to retry from 0-20 requests with 30ms apart, if I lower the time between requests, it starts increasing in timeouts, etc...
so, while officialy there is no rate limit, some people did mention 1000 requests per second here and there, I often find it better and more stable not to push that many request, also there is no need for it realistically

[umutyerebakmaz]

That's not a rate limit. It's just a lot of endpoints tend to randomly throw errors and there is a error limit.
Some endpoints like mail sending has a undocumented rate limit

[umutyerebakmaz]

semantically you are correct... however, if I increase rate of request and number of errors increases, then it's effectively rate limited, no matter how you call it... if it quacks, it's a duck 😄

but this is my personal experience and opinion, others might disagree and that is completely fine

[umutyerebakmaz]

semantically sure
but there is a thing we explicitly call a "Rate Limit"
then there is an effective rate limit, these words my be basically the same thing, but we place a literal meaning, or probably even a proper noun on one thing and not the other
ESI has a shit limit, in that its really bad

[umutyerebakmaz]

why do you worry about image caching ? Just link them on the client and let the client and image server handle cache themselve. You are not the one using the resource, AFAIK.

[umutyerebakmaz]

There is no general rule.
ESI is supposed to be limit-rated (which is a goood thing), so as long as you hit a cache you should not have an issue. However sometimes even hitting a cache produces invalid results, and some queries are not cached . Also some queries WILL generate errors (like contract items) so there is no real silver bullet.