onair

A small Rust binary that turns a Philips WiZ smart bulb red whenever you're on a Microsoft Teams call. Mount it somewhere visible at home and your family stops wondering whether they can interrupt you.

No cloud. No Microsoft Graph API. No phone app middleman. Just a single binary on your laptop that watches Teams' own log file and speaks UDP directly to the bulb on your home network.

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Features

• Auto-detects Teams call status by tailing the local MSTeams_*.log file. No auth, no permissions, no Graph API.
• Drives a Philips WiZ bulb over local UDP (port 38899). Discovery is automatic; you can also pin a known IP.
• Cross-platform — macOS, Windows, Linux. Single statically-linked binary, no runtime dependencies.
• Local web dashboard at http://localhost:9876:
  • Live beacon that mirrors the bulb's actual color (read back via getPilot)
  • Console with the live event stream
  • Settings: bulb selection, work hours, grace period, color/brightness for call vs. idle states, manual override
• Configurable work hours so it doesn't trigger after-hours
• Grace period (default 10s) so back-to-back calls don't cause the bulb to flicker off-on-off
• Manual override — Force Red / Force Off / Auto buttons, useful for "I'm in a deep-work session, leave me alone"
• SQLite persistence — all settings + call history survive restart
• First-run convenience — if exactly one WiZ bulb is on your LAN at startup, it's auto-selected

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Demo

Idle, no call:

Mid-call wrap-down (the spinner ring shows the grace timer counting down):

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Install

Pre-built binaries

Download from the Releases page for your OS:

• macOS — Apple Silicon (onair-aarch64-apple-darwin.tar.gz) or Intel (onair-x86_64-apple-darwin.tar.gz)
• Windows — onair-x86_64-pc-windows-msvc.zip
• Linux — onair-x86_64-unknown-linux-gnu.tar.gz

Extract and run. There are no dependencies — the binary is fully self-contained.

Build from source

You'll need Rust (stable, 1.75+):

git clone https://github.com/dannotes/onair.git
cd onair
cargo build --release
./target/release/onair

The release binary is around 5–8 MB depending on platform.

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Quick start

1. Run the binary — onair (or onair.exe on Windows).
2. The dashboard opens in your default browser automatically (the first time only). If for some reason it doesn't, visit http://localhost:9876.
3. If your WiZ bulb is on the same LAN and powered on, it gets auto-selected. Otherwise expand Settings → Bulb Selection → Scan Network and click your bulb.
4. The bulb will turn red the next time Teams shows you as Busy or Do Not Disturb.
5. Optional — make it run forever: expand Settings → Advanced and flip the Run on Login toggle. Onair will then start automatically on every login (you can close the terminal, reboot, and it just keeps working). Toggle off any time to disable.

That's it. The defaults are sensible and there's nothing else to configure unless you want to.

First-run permission prompts

The first time onair runs, your OS may pop one or two privacy prompts. Click Allow on both — they're expected and onair only needs them for what it says on the tin:

• macOS Sequoia (15.x): "onair would like to access data from other apps" Triggered because the Teams log lives in Microsoft's Group Container directory under ~/Library/. Onair only reads the file; it never writes to Teams' container.
• macOS Sonoma+ (14.4+): "onair would like to find and connect to devices on your local network" Triggered when onair sends UDP discovery / getPilot to the bulb on your LAN. Required for any LAN bulb control. If you miss this prompt, broadcast and unicast UDP get silently dropped — symptom is "0 bulbs found" while the bulb is clearly online (you can ping it but onair can't reach it). Re-run onair, watch for the prompt, click Allow. Or open System Settings → Privacy & Security → Local Network and toggle onair on manually.
• Windows / Linux: no first-run prompts. Just runs.

The grant is per-binary, so if you uninstall onair and reinstall it, you'll get the prompts again.

Run on Login

Open the dashboard, expand Settings → Advanced, and flip the Run on Login toggle. Onair gets installed as the OS-native autostart entry — a launchd LaunchAgent on macOS, a systemd user unit on Linux, or a Startup-folder shortcut on Windows. Toggle off any time to remove it cleanly. No manual file editing required, ever, and disabled by default so installing onair never modifies your login items without your explicit consent.

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How it works

┌─────────────────────┐                        ┌──────────────┐
│  your laptop        │ ─── UDP 38899 ──────►  │  WiZ Bulb    │
│                     │                        │  (on the LAN)│
│  onair binary       │  ◄── getPilot reply ── └──────────────┘
│                     │
│  - tails Teams log  │           HTTP
│  - drives the bulb  │  ◄────────────────────  your browser
│  - serves dashboard │     localhost:9876
│  - SQLite config    │
└─────────────────────┘

The state machine:

                              busy / dnd
   ┌──────────────┐  ──────────────────────►  ┌──────────────┐
   │  available   │                           │  on a call   │
   │  bulb off    │  ◄─────────────────────── │  bulb red    │
   └──────────────┘   available + grace 10s   └──────────────┘
          ▲                                            │
          │                                            │
          └────────── if back to busy within ──────────┘
                       grace, stay red
                       (back-to-back calls)

A small monitor task polls the latest MSTeams_*.log every 3 seconds (configurable), reads only new bytes since the last poll, and watches for presence transitions. Independently, a second task polls the bulb's getPilot every 5 seconds so the dashboard beacon shows the bulb's actual color, not a guess.

When Teams flips Busy → Available, a 10 second grace timer starts. If you go busy again within that window, the bulb stays red. Otherwise the timer expires and the bulb turns off (or whatever you've configured for "When Not on a Call").

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Configuration

Everything is editable from the dashboard's Settings panel. There's no config file you need to touch by hand.

Setting	Default	What it does
Work Start / End	06 / 18	Hour-of-day window. Outside these hours new presence transitions are ignored, but an active call keeps the bulb red until it actually ends.
Poll Interval	3 s	How often to check the Teams log for new presence events
Grace Period	10 s	How long to wait after busy → available before turning the bulb off
Max Call Cap	4 hours	Safety cap. If the bulb stays red for this long (e.g. Teams crashed), revert to idle.
Teams Offline	5 min	If the Teams log hasn't been written to for this long, treat Teams as offline and turn the bulb off
When On a Call	red @ 100%	Color and brightness — or off, if you want an inverted setup
When Not on a Call	off	Color/brightness or off. Set to a warm white if you want an always-on ambient lamp.
UI Port	9876	Dashboard port (restart required)

Config and call history are stored in a small SQLite database at:

• macOS: ~/Library/Application Support/Onair/onair.db
• Windows: %APPDATA%\Onair\onair.db
• Linux: ~/.config/onair/onair.db

You can delete this file at any time — the next run will recreate it with defaults and re-detect your bulb.

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Cross-platform notes

OS	Status	Default Teams log path
macOS	Verified	~/Library/Group Containers/UBF8T346G9.com.microsoft.teams/Library/Application Support/Logs/
Windows	Believed correct (per Microsoft's spec for the new Teams)	%LOCALAPPDATA%\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams\Logs\
Linux	Best-effort guess	~/.config/Microsoft/Microsoft Teams/logs/

Teams logs the user's status differently per platform:

• Windows writes lines like ... TaskbarBadgeServiceLegacy: ... GlyphBadge{"busy"} ...
• macOS writes lines like ... UserDataCrossCloudModule: CloudStateChanged: ... { availability: Busy, ... }

onair has a separate regex per OS that normalizes both to the same internal Presence enum.

If your Teams installs the log somewhere else, open Settings, paste the path into Teams Log Path, click Verify, and onair will check that the directory contains real log files and confirm the parser can find a presence event in them.

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Run on startup

Drop-in templates for all three OSes live in dist/autostart/. Pick your platform and follow the README in that folder — it's a 30-second copy-paste:

OS	Mechanism	File
macOS	launchd LaunchAgent	dist/autostart/macos/com.dannotes.onair.plist
Linux	systemd user unit	dist/autostart/linux/onair.service
Windows	Startup folder shortcut (PowerShell installer)	dist/autostart/windows/install-startup.ps1

Quick start (macOS, assuming you installed via Homebrew):

cp dist/autostart/macos/com.dannotes.onair.plist ~/Library/LaunchAgents/
launchctl load ~/Library/LaunchAgents/com.dannotes.onair.plist

Quick start (Linux):

mkdir -p ~/.config/systemd/user
cp dist/autostart/linux/onair.service ~/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now onair

Quick start (Windows, in PowerShell):

.\dist\autostart\windows\install-startup.ps1

See dist/autostart/README.md for full instructions, log locations, and how to uninstall.

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API

The dashboard is just a thin client on top of a small JSON API. You can hit it directly with curl:

Method	Path	Purpose
GET	/	the embedded dashboard HTML
GET	/api/status	full live snapshot — presence, bulb state, override, stats
GET	/api/logs	event ring buffer (?limit=&offset=)
GET	/api/config	current config
POST	/api/config	partial config update
POST	/api/override	{"mode": "auto" | "force_red" | "force_off"}
POST	/api/discover	trigger LAN bulb discovery
POST	/api/bulb/select	{"mac": "...", "ip": "optional"}
GET	/api/bulb/state	cached getPilot snapshot
POST	/api/bulb/test	{"mode": "call" | "idle"} — flash bulb in that mode for 3 s
POST	/api/teams/verify	verify a Teams log directory works
GET	/api/calls	call history (?days=)

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Tech stack

• Rust 2021, async with Tokio
• Axum for the web layer
• rusqlite (bundled) for persistence
• Vanilla HTML + CSS + JS for the dashboard — no framework, no build step. Embedded in the binary via include_str!.

The whole project compiles to a single binary with zero runtime dependencies.

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Credits

• Fonts: DM Sans (headings) and JetBrains Mono (everything else), via Google Fonts.
• The WiZ UDP protocol has been documented by various community efforts; this implementation works against off-the-shelf WiZ bulbs with no firmware modification.

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License

MIT — do whatever you want with it.

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Contributing

Issues and PRs welcome. Two things would help most right now:

1. Verify the Windows path + GlyphBadge regex against a real Windows Teams installation. The defaults are believed-correct from the Microsoft spec but unverified on real hardware.
2. Verify or update the Linux path — Teams on Linux is uncommon and may have moved.

If your default doesn't work, the manual path override + Verify button in Settings is the workaround in the meantime.