Most responses in the API are cached on the server, and the appropriate HTTP headers are set when this happens. Typically this will only be on GET requests. The response will contain the headers Last-Modified andExpires, as well as the Cache-Control header. It is strongly encouraged to obey these headers when making requests to the API. If you must have up-to-the-second data at all times, the cache can be revalidated on demand by including the header Cache-Control: no-cache on your request.