Border router device guide for iOS

iOS app developers can use the Home APIs to manage a Thread border router.

The GoogleBorderRouterDevice is implemented using two primary device traits: ThreadNetworkCapabilitiesTrait, which provides read-only attributes to inspect border router features, and ThreadNetworkManagementTrait, which handles network lifecycle commands and credential sharing using an Ephemeral Pre-Shared Key for the Commissioner (ePSKc). Structure-level internet access policies are managed using the ThreadNetworkSettingsTrait trait.

Always check for attribute and command support for a device prior to using any features or attempting to update attributes. See Control devices on iOS for more information.

Home APIs Device Type Traits Swift Sample App Use Case

Border Router

GoogleBorderRouterDeviceType

home.matter.6006.types.0161

 Required Traits
     google ThreadNetworkCapabilitiesTrait
     google ThreadNetworkManagementTrait

 Border router

Get basic information about a device

The BasicInformation trait includes information like vendor name, vendor ID, product ID, product name (includes model information), and software version for a device:

let vendorName = basicInfoTrait.attributes.vendorName!
let vendorID = basicInfoTrait.attributes.vendorID!
let productID = basicInfoTrait.attributes.productID!
let productName = basicInfoTrait.attributes.productName!
let softwareVersion = basicInfoTrait.attributes.softwareVersion!

Inspect border router capabilities

You can examine a border router's read-only capabilities (such as ePSKc support and Internet Access setting configuration) using the ThreadNetworkCapabilitiesTrait trait.

func checkBorderRouterCapabilities(device: HomeDevice) async {
    // Filter for GoogleBorderRouterDevice device type
    guard let gtbrDevice = device.type(Google.GoogleBorderRouterDevice.self) else {
        print("Device is not a Google border router.")
        return
    }

    // Retrieve the ThreadNetworkCapabilitiesTrait
    guard let capabilitiesTrait = gtbrDevice.traits(Google.ThreadNetworkCapabilitiesTrait.self) else {
        print("ThreadNetworkCapabilitiesTrait not found on device.")
        return
    }

    do {
        let isEpskcSupported = try await capabilitiesTrait.epskcSupported.read()
        let internetAccessOption = try await capabilitiesTrait.internetAccessOption.read()
        let isIasSupported = internetAccessOption != .none

        print("ePSKc Supported: \(isEpskcSupported)")
        print("Internet Access Setting Supported: \(isIasSupported)")
    } catch {
        print("Failed to read capabilities: \(error)")
    }
}

Manage Thread credential sharing (ePSKc)

Thread credential sharing is achieved using an Ephemeral Pre-Shared Key for the Commissioner (ePSKc). ePSKc mode generates a temporary, secure passkey that external devices or commissioners can use to securely obtain the Thread network dataset.

Activate ePSKc mode

func startEpskcSession(device: HomeDevice, durationSeconds: Int16) async -> Google.ThreadNetworkManagementTrait.ActivateEpskcModeResponse? {
    guard let gtbrDevice = device.type(Google.GoogleBorderRouterDevice.self),
          let mgmtTrait = gtbrDevice.traits(Google.ThreadNetworkManagementTrait.self) else {
        print("ThreadNetworkManagementTrait not found.")
        return nil
    }

    do {
        var request = Google.ThreadNetworkManagementTrait.ActivateEpskcModeRequest()
        request.requestedDurationSeconds = durationSeconds

        let response = try await mgmtTrait.activateEpskcMode(request)

        print("ePSKc Session Activated!")
        print("Status: \(response.status)")
        print("Ephemeral PSKc: \(response.epskc)")
        print("Valid Duration (s): \(response.validDurationSeconds)")

        return response
    } catch {
        print("Failed to activate ePSKc mode: \(error)")
        return nil
    }
}

Deactivate ePSKc mode

func stopEpskcSession(device: HomeDevice) async {
    guard let gtbrDevice = device.type(Google.GoogleBorderRouterDevice.self),
          let mgmtTrait = gtbrDevice.traits(Google.ThreadNetworkManagementTrait.self) else {
        return
    }

    do {
        try await mgmtTrait.deactivateEpskcMode(Google.ThreadNetworkManagementTrait.DeactivateEpskcModeRequest())
        print("ePSKc mode deactivated.")
    } catch {
        print("Failed to deactivate ePSKc mode: \(error)")
    }
}

Observe ePSKc deactivation events

Thread border routers emit events when an ePSKc session ends (for example, because the key was used, the session expired, or it was manually cancelled).

func observeEpskcEvents(device: HomeDevice) async {
    guard let gtbrDevice = device.type(Google.GoogleBorderRouterDevice.self),
          let mgmtTrait = gtbrDevice.traits(Google.ThreadNetworkManagementTrait.self) else {
        return
    }

    do {
        for try await event in mgmtTrait.epskcModeDeactivatedEvent.stream() {
            print("ePSKc Session Ended. Reason: \(event.reason)")
            switch event.reason {
            case .keyUsed:
                print("Key was successfully used to commission a device.")
            case .expired:
                print("Session timed out before the key was used.")
            case .cancelled:
                print("Session was manually cancelled.")
            @unknown default:
                print("Unknown deactivation reason.")
            }
        }
    } catch {
        print("Error streaming ePSKc events: \(error)")
    }
}

Manage Thread network membership

You can command a Thread border router to join a new Thread network by providing the active Operational Dataset TLVs, or command it to leave its current network.

func joinNetwork(device: HomeDevice, datasetTlvs: Data) async {
    guard let gtbrDevice = device.type(Google.GoogleBorderRouterDevice.self),
          let mgmtTrait = gtbrDevice.traits(Google.ThreadNetworkManagementTrait.self) else {
        return
    }

    do {
        var request = Google.ThreadNetworkManagementTrait.JoinNetworkRequest()
        request.operationalDatasetTlvs = datasetTlvs

        let response = try await mgmtTrait.joinNetwork(request)
        print("Join network command sent. Status: \(response.status)")
    } catch {
        print("Join network failed: \(error)")
    }
}

func leaveNetwork(device: HomeDevice) async {
    guard let gtbrDevice = device.type(Google.GoogleBorderRouterDevice.self),
          let mgmtTrait = gtbrDevice.traits(Google.ThreadNetworkManagementTrait.self) else {
        return
    }

    do {
        try await mgmtTrait.leaveNetwork(Google.ThreadNetworkManagementTrait.LeaveNetworkRequest())
        print("Leave network command sent successfully.")
    } catch {
        print("Leave network failed: \(error)")
    }
}

Configure structure-level internet access

The ThreadNetworkSettings trait is an updatable trait attached to a Structure (representing a home or building). It allows developers to configure the structure-wide internet access policy for Thread border routers.

func updateStructureInternetAccess(structure: Structure, enableInternetAccess: Bool) async {
    guard let settingsTrait = structure.traits(Google.ThreadNetworkSettingsTrait.self) else {
        print("ThreadNetworkSettingsTrait not found on structure.")
        return
    }

    let option: Google.ThreadNetworkSettingsTrait.InternetAccessOption = enableInternetAccess ? .internetAccessOptionAll : .internetAccessOptionNone

    do {
        try await settingsTrait.update { mutator in
            mutator.internetAccessOption = option
        }
        print("Successfully updated Thread internet access policy.")
    } catch {
        print("Failed to update Thread internet access policy: \(error)")
    }
}