We basically expose the pagination information all via header attributes, as follows:
keyeg. valuedescription
X-Total-Count123Information about the total records the query will return in total (all pages)
Link<https://api.bspk.com/api/extraction/v1/emails.json?page=2>; rel=‘next’, <https://api.bspk.com/api/extraction/v1/emails.json?page=18>; rel=‘last’Links for the last and next pages
For example, let’s make a curl request to the messages API, to find out how many message we have for the client CLI1: 
$ curl -I "https://api.bspk.com/api/extraction/v1/messages?client_ids=CLI1"
The -I parameter indicates that we only care about the headers, not the actual content. In examining the result, you’ll notice some information in the Link header that looks like this: 
HTTP/1.1 200 OK
Server: nginx
Date: Sat, 07 Aug 2021 22:34:11 GMT
Content-Type: application/json; charset=utf-8
X-Total-Count: 3000
Link: <https://api.bspk.com/api/extraction/v1/messages?client_ids=CLI1&page=2>; rel='next',
      <https://api.bspk.com/api/extraction/v1/messages?client_ids=CLI1&page=30>; rel='last'
Since by default, all paginated queries start at page 1, rel="last" provides more information stating that the last page of results is on page 30. Thus, we have 29 more pages of information about messages from client CLI1 that we can consume.
Important: Always rely on these link relations provided to you. Don’t try to guess or construct your own URL.