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

Operation : get_risk_list
Module : changes

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

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

$postfields["department_id"] = 1,2;
// This is the department_id

Below is example API URL to fetch risks

XML:
http://visiononlinedemo.com/support/api/index.php? 
vis_txtusername=admin
&vis_txtuserpass=21232f297a57a5a743894a0e4a801fc3
&vis_module=changes
&vis_operation=get_risk_list
&department_id=1,2

JSON: 
http://visiononlinedemo.com/support/api/index.php? 
vis_txtusername=admin
&vis_txtuserpass=21232f297a57a5a743894a0e4a801fc3
&vis_module=changes
&vis_operation=get_risk_list
&department_id=1,2
&vis_encode=json

OR use "access token" to fetch risks

XML:
http://visiononlinedemo.com/support/api/index.php?
vis_txttoken=WXprMk1UY3dZV1V6WWpZeU16RmpOelF3TVdReE5UWTJOVGMyTm1VeU4yUT0=
&vis_module=changes
&vis_operation=get_risk_list
&department_id=1,2

JSON 
http://visiononlinedemo.com/support/api/index.php?
vis_txttoken=WXprMk1UY3dZV1V6WWpZeU16RmpOelF3TVdReE5UWTJOVGMyTm1VeU4yUT0=
&vis_module=changes
&vis_operation=get_risk_list
&department_id=1,2
&vis_encode=json