Available since version: 1.8
       This method is used to link users or rights with user groups. Available only to super admins.
Multidimensional array with User groups data
       
| Parameter | Type | Optional | Description | Details | 
|---|---|---|---|---|
| usrgrpids | array | User group IDs. | ||
| userids | array | Yes | User IDs. | Those users will be added to all listed user groups in request. | 
| rights | array | Yes | Host group rights | Those rights will be added to all listed user groups in request. | 
| Parameter | Description | 
|---|---|
| result | Operation successful. Result will contain array of updated user group IDs. | 
| error | In case of any errors | 
Add two users with ID "100100000010092", "100100000010086" to user group with ID "100100000000013"
{
       "jsonrpc":"2.0",
       "method":"usergroup.massAdd",
       "params":{ 
           "usrgrpids": ["100100000000042"],
           "userids": ["100100000010092",  "100100000010086"],
       },
       "auth":"f223adf833b2bf2ff38574a67bba6372",
       "id":2
       }User groups updated successfully:
Add read rights on host group with ID "100100000010092" and read-write rights on host group with ID "100100000010093" to user group with ID "100100000000013"
{
       "jsonrpc":"2.0",
       "method":"usergroup.massAdd",
       "params":{ 
           "usrgrpids": ["100100000000043"],
           "rights": [
               {"permission": 2, "id": "100100000010092"},
               {"permission": 3, "id": "100100000010093"}
           ],
       },
       "auth":"f223adf833b2bf2ff38574a67bba6372",
       "id":2
       }User groups updated successfully: