Bandwidth Monitor (iOS)

SwiftUI client for awlx/bandwidth-monitor, showing live interface rates plus 1h / 24h traffic graphs, a Lock Screen widget, and a live Lock Screen / Dynamic Island view (Live Activity).

App Store release: https://apps.apple.com/gb/app/bandwidth-monitor-remote/id6784336088

Testflight betas: https://testflight.apple.com/join/DqxpPZ13

Feel free to use https://mp01.spodder.com as the endpoint to test.

App (Traffic)	Lock Screen widget

The chart mirrors around zero — download above the line, upload below — in Mbps (decimal bits). The Lock Screen widget shows the same shape as a monochrome sparkline for the selected interface.

• Xcode 16+ (iOS 17 deployment target, uses Swift Charts)
• A running bandwidth-monitor instance reachable on your network (e.g. http://192.168.1.1:8080)

open BandwidthMonitor.xcodeproj

Build and run on a simulator or device, then open the gear icon and set your server's address.

The project file is generated by xcodegen from project.yml. If you add/remove source files or change build settings, edit project.yml and regenerate:

xcodegen generate

The version lives in one place — MARKETING_VERSION and CURRENT_PROJECT_VERSION in project.yml; both Info.plists reference those build settings. scripts/release.sh automates the bump → regenerate → commit → tag → GitHub Release flow:

scripts/release.sh 0.9.1     # cut a release: set marketing version, bump build, tag v0.9.1, publish
scripts/release.sh bump-build # just bump the build number for a new TestFlight/App Store upload
scripts/release.sh 1.0.0 --no-build   # skip the compile check

It refuses to run on a dirty tree or an existing tag, and compile-checks before tagging (unless --no-build). Needs xcodegen and an authenticated gh.

It polls two endpoints on the Go server (see that repo's README "API Endpoints" section for the full list):

• GET /api/interfaces — current per-interface rates, polled every ~2s for the live list.
• GET /api/interfaces/history — up to 24h of per-second {t, rx, tx} samples per interface, polled every ~16s. The 1H/24H toggle just filters this client-side and downsamples to a few hundred points for the chart — no separate "1h" endpoint exists server-side.

Plain HTTP to a LAN router IP requires NSAllowsArbitraryLoads (set in project.yml) and triggers iOS's local-network permission prompt (NSLocalNetworkUsageDescription).

BandwidthMonitor/
  App/             App entry point
  Services/        LiveActivityController (start/update/end the Live Activity)
  Shared/          Code shared with the widget extension:
    Models/        Decodable types mirroring the Go server's JSON
    Networking/    APIClient (URLSession-based)
    Settings/      App Group accessors + widget snapshot cache
    Utilities/     BitRateFormatter (Mbps/kbps)
    LiveActivity/  ActivityKit attributes + content state
  ViewModels/      Polling + chart-windowing logic
  Views/           SwiftUI screens
BandwidthMonitorWidget/   WidgetKit extension: Lock Screen sparkline + Live Activity UI

BandwidthMonitorWidget is a WidgetKit extension (accessoryRectangular family) showing a monochrome sparkline for one interface: RX plotted above the zero line, TX plotted below it, no color, no axes. It reads the server URL and selected interface from an App Group (group.com.evilforbeginners.BandwidthMonitor, shared via BandwidthMonitor/Shared/Settings/AppGroup.swift) so it can fetch data on its own, independent of the host app.

Notes:

• In Xcode, you'll likely need to set your Team on both targets and confirm the App Groups capability is enabled for group.com.evilforbeginners.BandwidthMonitor on each (Signing & Capabilities tab) before it'll build/run on device.
• Widget timelines are refreshed by the OS on its own schedule (here requested every ~15 min) — this is not a live view. The graph reflects whatever the server returned at the last refresh, not a real-time sliding window.
• The app calls WidgetCenter.shared.reloadTimelines when you change the server URL or selected interface, so the widget updates promptly after a settings change even though it's otherwise on a slow OS-driven cadence.

The "Go Live" toolbar button starts an ActivityKit Live Activity that shows the selected interface on the Lock Screen and Dynamic Island: current ↓/↑ rates in Mbps and the same mirrored sparkline as the app. The latest sample is marked with a dashed "now" rule on the x-axis plus emphasised dots on the latest RX/TX points; a synthetic "now" sample carrying the live rate is appended so that marker tracks the current rate rather than the (up to ~16s old) tail of the history series.

• Pieces: BandwidthActivityAttributes (Shared/LiveActivity), BandwidthLiveActivity (the widget extension's Lock Screen + Dynamic Island UI), LiveActivityController (Services). The app target sets NSSupportsLiveActivities.
• Updates are local while the app runs. To keep it ticking while the app is suspended, the app registers its push token with a shared relay gateway, which polls your bandwidth-monitor server's existing plain API itself and pushes updates via ActivityKit / APNs — your server needs no APNs setup of its own. See docs/live-activity-push.md for details.

The Go server also exposes DNS, WiFi, NAT, speed test, and debug data (/api/dns, /api/wifi, /api/conntrack, etc.) that could be added as further tabs or widgets following the same pattern.