API:Ratelimit

Various actions of the API can be rate limited.

The actual values of the rate limits can vary per wiki configuration via the $wgRateLimits, $wgAccountCreationThrottle and $wgPasswordAttemptThrottle parameter. Normally if your account has the noratelimit right (e.g. Is in the Bot or Admin group), then these rate limits don't apply. If using OAuth you have to ensure your OAuth grant includes the highvolume grant for this to apply.

You can view what the actual limits that apply to you are via the meta=userinfo query api module. For example: https://en.wikipedia.org/w/api.php?action=query&meta=userinfo&uiprop=ratelimits

Some endpoints also have concurrency limits, where there is a max number of requests that can happen at the same time. This is controlled by $wgPoolCounterConf. It is disabled by default in MediaWiki, but is enabled on Wikimedia wikis.