---
title: "subscribeAttributeOctetString(with:subscriptionEstablished:reportHandler:)"
framework: matter
role: symbol
role_heading: Instance Method
path: "matter/mtrbaseclusterunittesting/subscribeattributeoctetstring(with:subscriptionestablished:reporthandler:)"
---

# subscribeAttributeOctetString(with:subscriptionEstablished:reportHandler:)

## Declaration

```swift
func subscribeAttributeOctetString(with params: MTRSubscribeParams, subscriptionEstablished: MTRSubscriptionEstablishedHandler?, reportHandler: @escaping (Data?, (any Error)?) -> Void)
```