Additional Headers in API Responses
Beginning April 12, 2016, developers will notice the additional presence of “X-Rate-Limit”-type headers in the responses of API calls. These are informational in nature at this time.
The data in the headers reference cap values that are practically infinite, so there is no limitation being imposed at this time. The release of these headers also ties to additional internal monitoring of per-second API call usage.
These headers follow Twitter’s API Convention, which is similarly used in many SaaS products. As the popularity of this header convention shows, rate limiting is crucial to system health and traffic management. It provides a universally consistent experience for all users, ensuring that no single source can overwhelm system resources. With system performance foremost in mind, this is the first step in moving toward system-wide rate limiting in our platform in late 2016.
In late April 2016, we will provide more information about the extensive roll-out window for API rate limiting. We will also provide updated client libraries for developers, detailed documentation on the limiting behavior, integration guidelines and, most importantly, a full timeline for the implementation of limiting.
For integrations already adhering to our best practice guidelines for per-second request limits (available in our Support Knowledge Base), rate limiting will only solidify those best practices as hard limits. Our Customer Success team is already contacting existing customers exhibiting excessive call usage.