All successful GET requests responses return an ETag header. You can use the ETag value to make
subsequent requests to those resources using the If-None-Match header. If the resource has not changed,
the server returns a 304 Not Modified.
Making a conditional request and receiving a 304 response does not count against your Rate Limit,
so we encourage you to use it whenever possible.
#Examples
Without If-None-Match Header
GET /orders HTTP/1.1
GET /orders HTTP/1.1 200 OK
ETag: "644b5b0155e6404a9cc4bd9d8b1ae730"
With If-None-Match Header
GET /orders HTTP/1.1
If-None-Match: "644b5b0155e6404a9cc4bd9d8b1ae730"
GET /orders HTTP/1.1 304 Not Modified
ETag: "644b5b0155e6404a9cc4bd9d8b1ae730"
