Wednesday, 30 August, 2017 UTC


Over the years our legacy APIs have not had rate-limiting built into them, other than the implicit, informal rate limiting caused by performance bottlenecks. Most of the time, for most users of our public APIs, this has been sufficient. As the registry grows, however, we’ve seen heavier use of our APIs, some of which has been heavy enough to prompt us to take action. If we can identify the user and suspect it’s a bug, we reach out. Sometimes we simply block IPs when the usage is at levels that affect other people’s ability to use the APIs.
This isn’t ideal, and we’d rather give clear signals to API users what the allowed rates are and when they are being rate-limited. We’re therefore rolling out more explicit rate-limiting for all registry apis. Your tools should be ready to handle responses with http status code 429, which means that you have exceeded the allowed limit.
We will be allowing logged-in users to make requests at a higher rate than anonymous users.
For some services we have already begun limiting the amount of data that can be requested at a time. For example, we limit package search requests to queries that are at least three characters long. We have also taken steps to prevent API users from exploiting bugs to work around that limit.
We’ve also re-instituted limits in our downloads API. Our previous implementation of this API limited data ranges to well under a year for performance reasons. Our current implementation performs much better but turned out to have its breaking point as well,. You may now request at most 18 months of data at a time for single-package queries. Bulk package data queries are limited to at most 128 packages and 365 days of data.
We reserve the right to further limit API usage without warning when we see a pattern of requests causing the API to be unusable for most callers. We’ll follow up with documentation in these cases. Our primary goal is to prevent API use from either deliberately or accidentally making the service unresponsive for other users.
All of our existing registry API documentation is available in the registry repo on GitHub, and you can find the most up-to-date statements about our rate-limiting policies there.