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Ultra-low-latency live view of a phone's camera (or any browser's screen) on a TV/screen, over your LAN. WebRTC peer-to-peer; the server only relays signaling and never sees media. ~80–200 ms glass-to-glass on a healthy 5 GHz LAN; 1080p60 at up to 20 Mbps.

No Google Cast SDK, no public hosting, no STUN/TURN — iceServers: [] so the connection can only resolve over LAN candidates.

Pre-built multi-arch image at ghcr.io/jensenbox/reflektor:latest.

curl -O https://raw.githubusercontent.com/jensenbox/reflektor/main/docker-compose.yml
echo "LAN_IP=$(hostname -I | awk '{print 1ドル}')" > .env # or set it manually, e.g. 192.168.1.10
docker compose up -d

Then on each device:

(reflektor.local resolves via mDNS — see "Configuration" below. You can always fall back to https://<LAN_IP>:8443/.)

The container auto-updates clients: every redeploy issues a new server UUID, and live pages reload themselves the moment they reconnect.

• Cam / Resolution / Codec — selectors persist across reloads.
  • H.264 efficient on most Android phones.
  • AV1 is best when the TV has hardware AV1 decode (many recent Hisense panels).
• Audio: off/on — include mic (camera mode) or system audio (screen mode) in the stream. Default off.
• Start — opens the chosen camera and begins streaming.
• Screen — alternative source: getDisplayMedia(). Useful for mirroring a laptop to the TV.
• Screen off — blanks the OLED preview to save phone power while continuing to stream. Wake lock holds the screen on.
• Lock — locks current screen orientation (PWA / fullscreen only).
• Probe — embeds a 32-bit timestamp barcode in every frame; receiver decodes it and displays end-to-end latency live.
• Install — PWA install prompt (needs trusted cert — install /ca.crt to unlock).

State (streaming, probe-on, screen-off) is restored after auto-reloads within the same tab session.

• Fullscreen <video>, muted by default so autoplay always wins after reloads.
• Stats overlay — tap to show breakdown (resolution, codec, decode/assembly/jitter-buffer ms).
• Latency overlay — appears top-left as a big green number when Probe is active.
• Audio prompt — if a stream arrives with audio, a "Tap for sound" button appears (browsers require a gesture to unmute).
• Press F for fullscreen.

One-time host setup (the Alpine avahi client inside the container is protocol-incompatible with the host's avahi-daemon, so we publish host-side instead):

sudo ./scripts/install-host-mdns.sh

That installs avahi-daemon + avahi-utils if missing, drops a reflektor-mdns.service unit that runs avahi-publish-address, and starts it. After this, reflektor.local resolves to your host's IP from every device on the LAN. If you skip this, you reach the box by IP — everything else still works.

Set PIN= in .env to any string. Browsers prompt for credentials on the first request (any username, password = your PIN). The WS upgrade uses the same Basic auth, which Chrome/Firefox forward automatically once you've authenticated for the origin. /ca.crt and /healthz are always open so bootstrap and monitoring still work.

Set MULTI_RECEIVER=1 to let multiple receivers view the same stream at once (e.g., TV + tablet + laptop). The sender opens one WebRTC peer connection per receiver — encoding cost scales linearly, network cost too (no SFU). Fine for 2–3 receivers on a typical LAN.

When off (default), a new receiver replaces any existing one, same as the original behavior.

./setup.sh # generates ./certs from your LAN IP (auto-detected)
npm install
npm start

[Phone, Chrome PWA] ────getUserMedia──► WebRTC P2P (LAN only) ────► [TV browser <video>]
 ▲さんかく ▲さんかく
 └── WebSocket signaling (this server) ──┘

• server.mjs — HTTPS + WebSocket signaling relay, serves static pages, exposes /healthz and /ca.crt.
• public/sender.html — phone PWA. Captures camera or screen, prefers a chosen codec, caps bitrate at 20 Mbps. Optional audio + screen sharing + latency probe.
• public/receiver.html — TV/desktop. playoutDelayHint=0, jitterBufferTarget=0 for minimal buffering. Audio unmute prompt when audio track arrives.
• Signaling protocol: peerId-routed messages. hello (server → client with serverId + peerId), peer-joined / peer-left (server → sender), offer (sender → receiver, with to), answer (receiver → sender, with implicit from), ice (bidirectional, routed by to / from).

MIT