StageLinQ
StageLinQ is the protocol Denon DJ uses to share state between Prime-series
players and mixers. Now Playing implements it in the stagelinq package,
connecting over the local network to read track metadata, deck state, and mixer
signals in real time.
What It Connects To
Section titled “What It Connects To”- Denon SC6000 / SC6000M standalone media players.
- Denon SC5000 / SC5000M standalone media players.
- Denon Prime 4, Prime 2, Prime Go all-in-one units.
- Denon X1850 / X1800 DJ mixers.
- Engine DJ desktop software (shares the same protocol).
How It Works
Section titled “How It Works”The package discovers Denon devices on the network using mDNS service discovery. Once a device is found, it opens a TCP connection and negotiates the StageLinQ services available on that device:
- StateMap — a real-time state tracker covering 200+ per-deck values (current track, playback state, BPM, sync state, loop state, mixer positions).
- BeatInfo — per-beat tempo and beat-position messages.
- FileTransfer — lets Now Playing read metadata from the player’s database without a physical USB mount.
- TimeSync and Broadcast — auxiliary services used for clock synchronisation.
Now Playing subscribes to the state values it cares about. Denon hardware streams changes back as they happen, so tracking is event-driven rather than polling.
What Data Is Extracted
Section titled “What Data Is Extracted”| Field | StageLinQ Service |
|---|---|
| Track title, artist, album | StateMap |
| Track file path and database key | StateMap |
| BPM and musical key | StateMap |
| Playback state (playing / paused / cued) | StateMap |
| Channel fader and crossfader positions | StateMap |
| Deck sync state and master deck | StateMap |
| Beat position and live tempo | BeatInfo |
| Artwork | FileTransfer (from player database) |
Platform Support
Section titled “Platform Support”- macOS — fully supported.
- Windows — fully supported.
Wired Ethernet is recommended for the same reasons as PRO DJ LINK: real-time beat and state data flows continuously, and packet loss on Wi-Fi causes missed updates.
Relationship to Engine DJ
Section titled “Relationship to Engine DJ”Engine DJ desktop software speaks the same StageLinQ protocol over the local network. If you mix with Engine DJ on a laptop (rather than with Prime hardware), enabling StageLinQ as a source picks up the desktop app the same way it would pick up a physical player.