# Identify a user

## Custom Id

You can set a custom id in order to track/target users with id coming from different platforms.

To set a custom id:

```swift
MBAudience.setCustomId("CUSTOM_ID")
```

To remove it:

```swift
MBAudience.removeCustomId()
```

To retrieve the current saved id:

```swift
MBAudience.getCustomId()
```

## Mobile User Id

This is the id of the user currently logged in MBurger using MBAuth. At the moment the mobile user id is not sent automatically when a user log in/log out with MBAuth. It will be implemented in the future but at the moment you have to set and remove it manually when the user completes the login flow and when he logs out.

To set the mobile user id:

```swift
MBAudience.setMobileUserId(MOBILE_USER_ID)
```

To remove it, if the user logs out:

```swift
MBAudience.removeMobileUserId()
```

To get the currently saved mobile user id:

```swift
MBAudience.getMobileUserId()
```


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