<!--
{
  "availability" : [
    "iOS: 26.5.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "AccessoryTransportExtension",
  "identifier" : "/documentation/AccessoryTransportExtension/TransportMessage/sessionID",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "Accessory Transport Extension"
    ],
    "preciseIdentifier" : "s:27AccessoryTransportExtension0B7MessageV9sessionID10Foundation4UUIDVvp"
  },
  "title" : "sessionID"
}
-->

# sessionID

A unique identifier for the message’s capability session.

```
let sessionID: UUID
```

## Discussion

This identifier correlates messages with their capability (such as notifications or Live Activities). The system generates the session ID at feature enrollment time, and the value is fixed while the accessory remains paired through AccessorySetupKit.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)