Announcing API rate limits

TL;DR We are introducing rate limiting on our API endpoints from 14 September, 2021 — you'll be able to send up to 6 requests per second. This change is a first step towards supporting concurrent API calls which is a heavily-requested feature. We believe that this will allow us to provide an even better experience for our customers. 

Now, a bit more eloquent explanation.

What is changing?

Previously we were not rate limiting API requests at all: it was possible to send as many requests as needed. However, only one request at a time was allowed, and many customers were asking to enable concurrency. An important step in introducing this feature is limiting access to all endpoints to 6 reqs/sec which roughly means 1 request every 166 milliseconds (though there are some other factors that we take into consideration). Of course, if you send only two requests within, say, 50ms time frame, both will be served without any issues. You can even send 6 requests one after another with 1ms time delay and everything will work fine, however the seventh request sent in the same 1 second time frame will get rejected.

This change is applicable to both existing and new endpoints. If you exceed this limit, a 429 HTTP status code will be returned with the body in JSON format:

{
  "message": "Too many requests. Cool your jets and try again in a bit.",
  "details": "See https://app.lokalise.com/api2docs/curl/#resource-rate-limits for more information on API request rate limits."
}

We will update all our official API clients shortly to properly handle this error. 

This limit is applied per API token and per IP address.

When will these limits be introduced?

The new limits will be effective from 14 September, 2021 — there won't be any additional grace period. Therefore, we highly encourage you to make sure you are not sending more than 6 requests per second and adjust your API integrations accordingly.

All customers will also receive several notification emails reminding them to update their API integration code. Even if you don't receive an email, we still recommend checking your integrations code and making sure everything is in order to avoid any unpleasant surprises later.

If you have any additional questions on the topic, please don't hesitate to reach out to our support team — we will be happy to assist. Stay tuned!