// 2026.06.03

Turn Spectacles into a MIDI Controller — the MIDI Bleep Blop Starter

14:00 JST

MIDI Bleep Blop (package midi-bleep-bop) is a MIT-licensed TypeScript project from IoTone — an organizing partner of the hackathon — that lets a Snap Spectacles Lens generate MIDI notes and play them on real synths and DAWs (KORG Volca, GarageBand, Logic Pro, Ableton are all referenced). It is a creative, musical counterpoint to the visual starters we’ve covered, and a good hackathon seed if your idea involves sound.

A note up front: this is very new and experimental — version 0.1.0, a handful of commits, days old, actively developing. Treat it as a “watch this space” starter to clone and remix, not a finished package.

The interesting part: why there’s a bridge

The architecture is the real lesson here. Spectacles cannot speak MIDI directly to hardware, and the reason is specific: the Spectacles Bluetooth API lacks createBond() support, and commercial BLE-MIDI devices universally require bonding — so a peripheral that needs bonding silently hangs. Direct lens-to-hardware MIDI is therefore infeasible today.

MIDI Bleep Blop routes around this with a companion bridge:

Spectacles Lens ──ws/wss──► bridge (Node or Bun) ──► CoreMIDI / ALSA / WinMM ──► synth

The Lens uses a SpectaclesWebSocketTransport built on Lens Studio’s InternetModule WebSocket API; the bridge is a small Node/Bun server that talks to the OS MIDI subsystem via the JZZ library. This is also a transferable pattern: it’s the same “Lens talks to a companion app over WebSocket” trick you’d use for any hardware Spectacles can’t reach directly.

What’s in the repo

It is a TypeScript monorepo. The pieces that matter for a hackathon:

  • lens/MidiBleepBop.lspkg — the distributable Lens Studio package: a MidiClientComponent, a MidiClient prefab, and the bundled core + transport scripts. Drop it into your own Lens.
  • lens/TesterLens — an end-to-end Spectacles ‘24 Lens Studio project with a diagnostic panel and a NoteCubeFlash that reacts to incoming MIDI.
  • bridge/ — the Node/Bun WebSocket-to-MIDI server.
  • examples/, docs/ — runnable examples and unusually thorough docs (architecture, bridge, wire protocol, Spectacles API, grooves).

Higher-level building blocks include a ChordSender groove generator (triad, acid, house, trance patterns), a PianoKeyboard component, and a DeviceCatalogComponent for named CC parameters (e.g. a Volca Bass “Cutoff EG intensity”).

Getting it running

  1. Clone the repo, then npm install and npm run build (npm test runs the vitest suite).
  2. Pick a MIDI destination. The no-hardware path on macOS: enable the IAC Driver in Audio MIDI Setup and route into GarageBand/Logic/Ableton. With hardware: a WIDI Master / KORG BLE-MIDI dongle to a synth.
  3. Start the bridge — e.g. npm run play:gb for a GarageBand chord loop, or node bridge/dist/cli.js --device "IAC Driver Bus 1" --log debug. Confirm with curl http://127.0.0.1:8765/status.
  4. Open TesterLens in Lens Studio 5.9+ (5.10 recommended), enable Project Settings → Experimental APIs, and set the Bridge URL to your machine’s LAN IP — localhost resolves to the glasses, not your computer.
  5. Press Play in Preview and watch the status go connecting → open as the cube reacts to MIDI. From there, drop MidiClientComponent into your own Lens and call sendNoteOn / sendCC / sendPitchBend.

Caveats

  • Brand-new and experimental. v0.1.0, single-digit commits, 9 open issues. Expect rough edges.
  • The npm packages may not be published yet. The repo root is private, so lead with clone-and-build rather than npx.
  • A companion computer is required — the bridge can’t run on the glasses. Spectacles hardware itself is optional at first; Preview mode works.
  • Platform notes: ws:// needs Experimental APIs and can’t be published (published Lenses need wss:///TLS); there’s no device discovery (set the IP manually); no auth, so anyone on the LAN can send MIDI. macOS is the best-trodden path.

Questions? Reach the team via the Contact page.

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