XOSC opens a UDP socket and turns whatever the operating system reports — a key on a USB keypad, MIDI Note 60 on channel 1, button 9 on a generic gamepad, the ASCII line "BTN1_DOWN\n" coming out of an Arduino at 115 200 baud — into an OSC packet at 127.0.0.1:7000. Designed for Resolume Arena; works for any OSC receiver. One window, no daemons, no service to install.

The input matrix

• Keyboard — any key code with modifier capture (Ctrl / Alt / Shift / Meta). Discrete trigger, plus ASCII string payload for receivers that want the raw key name.
• MIDI via Web MIDI — Note On/Off, CC, Pitch Bend, Program Change. Channel and note number forward as OSC args; CC numbers fan out to addressable output nodes.
• Gamepad via the HTML5 Gamepad API, polled at 60 Hz. Buttons fire discrete triggers; axes forward raw floats. Up to four pads addressable independently.
• Serial on any COM port via node-serialport, line-buffered. Each unique line is its own trigger — wire an Arduino with five push-buttons and you have five named OSC events.

Signal chain

Capture → match → emit. The OS reports an event; the input bus normalizes it to a stable signature (midi:noteOn:1:60, kbd:F13, serial:COM4:BTN1_DOWN); the React Flow mapping graph routes it to every wired output node; each output node owns its host:port and emits a UDP packet. Pulse, Toggle, and Hold arg modes determine the payload shape. Multiple outputs fire in parallel — fan out to two Resolume machines, an Avolites desk, and a QLab cue stack at the same time.

How it's split

The renderer is React + React Flow: the mapping graph, the listeners that don't need Node (keyboard, Web MIDI, Gamepad API), and every UI surface. The main process owns the Node-only pieces: the node-osc UDP sender, serialport for COM input, Electron's globalShortcut for system-wide hotkeys, and a JSON config file at %APPDATA%\XOSC. IPC is a thin command channel — the renderer asks main to send OSC, register a shortcut, or open a serial port; main streams events back.

Ten themes, no purple-cyan-glossy

The whole UI is driven by a flat token map applied to :root — eight dark themes (Solder, Phosphor, Blueprint, Sodium, Rack, Console, Vapor, Obsidian) and two light (Bone, Newsprint). Each one repaints both the marketing site and the in-app graph live with no reload. The defaults are tuned for FOH operators staring at the screen for hours — high-contrast monospace, no gloss, no gradients, no glow.

How it ships

Tagging vX.Y.Z kicks GitHub Actions, which builds on windows-latest, runs NSIS for the installer, and uploads XOSC-Setup-X.Y.Z.exe to the GitHub release. The Astro site at xosc.gamingworld.uk auto-fetches the latest release for its download button. The whole pipeline is just release patch → git push --tags. Currently Windows-only and unsigned; macOS / Linux builds are scoped for after the mapping-graph editor lands its v0.2 polish pass.

Why "XOSC"

The X stands for "any" — any input, any output, any receiver. The original brief was a single binding for one Resolume macro from a USB foot-pedal; once the mapping graph existed, every other input class was a half-day of plumbing. The whole project is the FL-Studio "press the button you want to bind" experience, applied to OSC.