Evaluate feature flags

Roll out a guided firmware update experience to selected customers. Feature flags load automatically after BTX has a customer identity. Reads are synchronous and use your fallback until the first evaluation is available or when a key is unknown.

let useGuidedUpdater = BTX.featureFlags.isEnabled(
    "firmware-update-v2.enabled",
    fallback: false
)

Choose a fallback that keeps the host app safe when the network is unavailable or an evaluation has not loaded yet.

Observe the shared flag object and pass in your app’s existing update flows. Keep the same battery, connection, and firmware compatibility checks in both flows.

import SwiftUI
import BTXClientKit

struct FirmwareUpdateEntry: View {
    @ObservedObject private var flags = BTX.featureFlags
    let startGuidedUpdate: () -> Void
    let startStandardUpdate: () -> Void

    var body: some View {
        let guided = flags.isEnabled("firmware-update-v2.enabled", fallback: false)

        Button(guided ? "Update with guide" : "Update firmware",
               systemImage: "arrow.down.circle") {
            if guided {
                startGuidedUpdate()
            } else {
                startStandardUpdate()
            }
        }
    }
}

For a host-owned model, use BTX.featureFlags.onChange and retain its returned cancellable for as long as you want updates.

From an async main-actor context, refresh when the product flow needs a current evaluation immediately after an external change. Handle transport errors in the host.

let state = try await BTX.featureFlags.refresh()