# Query a user's permissioned products

This tutorial explains how you can use the _Permissioning API_ to find out from the server, which products the logged-in user is allowed to use, in order to display the appropriate information to the user.

When developing a component which deals with several products, you might want to find out which ones the user has permission to view or trade upon, before displaying them within the component.

**For example:** Imagine that you want to know which currency pairs to display in a selection list. The following code snippet can be used to customise the list’s contents:

```js
var permissionService = caplin.core.ServiceRegistry.getService("caplin.permission-service");

var pCurrencyList = ["/FX/GBPUSD","/FX/EURUSD","/FX/AUDUSD","/FX/GBPEUR",…];
var sNamespace = null;
var sAction = "VIEW";

var pPermissionedCurrencyList = permissionService.getPermissionedProducts(pCurrencyList, sNamespace, sAction);

//code to populate select box with pPermissionedCurrencyList
```

The "_getPermissionedProducts_" function, returns a subset of the array of products passed to it, containing only those which the user is allowed (in this particular example) to view. The complementary function "_getUnpermissionedProducts_" is also available.