This API is used to Get Change list
Please check example usage of Vision Helpdesk API

Operation : view_changes
Module : changes

$postfields["vis_module"] = "changes";
// This is the module under which you wish to perform operation

$postfields["vis_operation"] = "view_changes";
// This is the operation field

Similarly you can fetch changes using filter criteria:

$postfields["vis_module"] = "changes";
// This is the module under which you wish to perform operation

$postfields["vis_operation"] = "view_changes";
// This is the operation field

[Optional]

$postfields["vis_filter_id"] = 1;

$postfields["criteria"] = "test";

Below is example API URL to fetch changes

XML: http://visiononlinedemo.com/support/api/index.php? vis_txtusername=admin &vis_txtuserpass=21232f297a57a5a743894a0e4a801fc3 &vis_module=changes &vis_operation=view_changes JSON: http://visiononlinedemo.com/support/api/index.php? vis_txtusername=admin &vis_txtuserpass=21232f297a57a5a743894a0e4a801fc3 &vis_module=changes &vis_operation=view_changes &vis_encode=json 

OR use "access token" to fetch changes

XML: http://visiononlinedemo.com/support/api/index.php? vis_txttoken=WXprMk1UY3dZV1V6WWpZeU16RmpOelF3TVdReE5UWTJOVGMyTm1VeU4yUT0= &vis_module=changes &vis_operation=view_changes JSON: http://visiononlinedemo.com/support/api/index.php? vis_txttoken=WXprMk1UY3dZV1V6WWpZeU16RmpOelF3TVdReE5UWTJOVGMyTm1VeU4yUT0= &vis_module=changes &vis_operation=view_changes &vis_encode=json

Below is example API URL to fetch changes using filter criteria

XML: http://visiononlinedemo.com/support/api/index.php? vis_txtusername=admin &vis_txtuserpass=21232f297a57a5a743894a0e4a801fc3 &vis_module=changes &vis_operation=view_changes &vis_filter_id=1 &criteria=test JSON: http://visiononlinedemo.com/support/api/index.php? vis_txtusername=admin &vis_txtuserpass=21232f297a57a5a743894a0e4a801fc3 &vis_module=changes &vis_operation=view_changes &vis_filter_id=1 &criteria=test &vis_encode=json 

OR use "access token" to fetch changes using filter criteria

XML: http://visiononlinedemo.com/support/api/index.php? vis_txttoken=WXprMk1UY3dZV1V6WWpZeU16RmpOelF3TVdReE5UWTJOVGMyTm1VeU4yUT0= &vis_module=changes &vis_operation=view_changes &vis_filter_id=1 &criteria=test JSON: http://visiononlinedemo.com/support/api/index.php? vis_txttoken=WXprMk1UY3dZV1V6WWpZeU16RmpOelF3TVdReE5UWTJOVGMyTm1VeU4yUT0= &vis_module=changes &vis_operation=view_changes &vis_filter_id=1 &criteria=test &vis_encode=json