---
title: messageIdentifier
framework: groupactivities
role: symbol
role_heading: Type Property
path: groupactivities/custommessageidentifiable/messageidentifier
---

# messageIdentifier

A custom identification string for the current type.

## Declaration

```swift
static var messageIdentifier: String { get }
```

## Discussion

Discussion The string you return from this property must be unique among your app’s custom message types. When you send a message, GroupSessionMessenger includes this string in the data it sends to other devices. When it receives a message, GroupSessionMessenger creates the type that contains the matching string in this property.