What is rate limiting?
As a security measure, we limit user requests to our public API to a reasonable limit.
The limit is 20,000 requests per 24-hour period, and once that limit has been reached 500 requests per hour.
To put this into perspective, Vortex consumes 3 requests per mod download (Nexus Mod Manager currently consumes twice as many per mod download) meaning you could, in theory, download up to 6664 mods via Vortex (or 3332 via Nexus Mod Manager) before reaching the 20,000 request limit.
After that, you will then be limited to 500 requests per hour (around 165 mod downloads per hour via Vortex). Once you reach this hourly limit, you will be presented with a warning message upon making your 501st request:
Rate Limiting Error/Warning Message in Vortex
Rate Limiting Error/Warning Message in Nexus Mod Manager
Rate Limiting Error/Warning message in Mod Organiser
Once you have reached your limit - that is both the 20,000 request limit per 24h as well as the hourly 500 requests limit - you will be unable to make any more requests (such as mod downloads, mod update queries etc.) for the designated time frame (within the same hour). Please note that this measure is in place to protect our server infrastructure and maintain our site's functionality for all our users.
When you have been rate-limited you will then simply have to wait until you can make further requests to our API.
I have been rate-limited and have not downloaded anywhere close to 3300 mods in 24 hours. What is going on?
If you have been rate-limited, it is because you have exceeded our daily and hourly request limit. Note that mod downloads are just one way of making requests to our API. Other ways of making requests include e.g. querying mod updates or mod information via a mod manager or other applications referencing our API.
Please ensure that your mod manager is up to date to rule out the possibility of outdated software erroneously making an extraordinary amount of requests, which would lead to you being rate-limited.
When will my API limit reset?
The daily quota resets for all users at 00:00 GMT each day. The hourly quota resets each hour (e.g. 01:00 GMT, 02:00 GMT, etc).
How can I see my remaining API requests?
This information is sent in the response header to every request made to the API. Depending on which application you are using, there may be a way to see this number. For Vortex users, you can download this extension which adds a widget to the dashboard showing your remaining requests and reset times.