The link:  https://apidocs.symantec.com/home/SAEP  states that parameter "pageSize"  is the number of results to include on each page. By default the API call will return 25 clients per page.  The customer is looking for a way for all the clients to be returned in a single list.

Server 2012 Sepm 14.2

Adding the pageSize parameter to the API call can achieve the desired results. 

https://<SEPM IP>:8446/sepm/api/v1/computers?pageSize=600

After executing the call the returned results will contain upto the designated number.

Alternatively:

If you want to use other query options, you can append them to the API call with '&parameter name and value'. e.g. https://<SEPM IP>:8446/sepm/api/v1/computers?pageSize=600&order=DESC