Are there are any limits, restrictions, and rules when using the available endpoints of Jagex's API? I am specifically interested in the [link url=]https://secure.runescape.com/m=hiscore_oldschool/index_lite.ws[/link] endpoint. I want to use it but also want to abide to any rules to prevent misuse or overloading Jagex's servers.
Things I could think of are stuff like rate limits, concurrent usage, etc.
Hopefully one of the WebDev JMods can respond to you with certainty but from a common sense approach, as long as you're not bombarding their APIs then you'll be fine.
I had a system I built linked to my Clan website (which I believe is still running). My DB contained about 60/70 users and periodically using a cronjob I'd fetch the stats of each user using the Hiscores API. I either did it every hour or every 30 minutes. So that's 60/70 calls (per user) every 30 or 60 minutes.
How often are you thinking of fetching the data and for how many users?