Declarative OSC bridge for music hardware and software
@roomi-fields
Declarative OSC bridge for music hardware and software — and an MCP server to drive it from an LLM.
849 hardware synthesizers over MIDI / SysEx, plus DAWs and live-coding environments over OSC (Ableton, Bitwig, Reaper, Sonic Pi, SuperCollider, Pure Data, TouchDesigner, VCV Rack). Every device gets a clean, named OSC surface described by one JSON file. Drive it from a live-coding client, a DAW, a script, the CLI — or from Claude via the built-in MCP server (a MIDI MCP and OSC MCP).
Why a bridge? Modern synths — hardware and software alike — expose themselves over MIDI, SysEx, and OSC with proprietary, scattered protocols. Using them from live-coding environments, a DAW, a script, or an LLM is painful:
CC / NRPN addresses are cryptic SysEx byte formats are hand-rolled per device Bidirectional state (what the device CURRENTLY knows) is hard to track osc-bridge gives every supported synth a clean, named OSC surface:
~mb = NetAddr("127.0.0.1", 7777); ~mb.sendMsg("/minilab3/knob/3/cc_number", 64); // reconfigure knob 3 ~mb.sendMsg("/minilab3/pad/0/color", 127, 0, 0); // pad 1 red ~mb.sendMsg("/minilab3/display/text", "Hello", "World"); Each synth is described by one JSON file. No Rust recompile required to add a device.
What makes it different One JSON = one driver. Adding a synth is ~30 lines of declarative JSON — CC numbers, SysEx frame templates, optional parameter tables. No Rust, no bindings, no build step. Ship a PR, osc-bridge run picks it up. 849 devices out of the box. Every Prophet, every Oberheim, every Yamaha DX-family, MatrixBrute, Hydrasynth, Virus TI, Digitone, Matrix-1000… most of the catalogue is usable today. Fully searchable at roomi-fields.github.io/osc-bridge. Hardware and software. The same named OSC surface drives a hardware synth over MIDI/SysEx or a DAW / live-coding environment over OSC — Ableton, Bitwig, Reaper, Sonic Pi, SuperCollider, Pure Data, TouchDesigner, VCV Rack. See § Software targets. An MCP server built in. osc-bridge mcp exposes the whole catalogue to Claude (or any MCP client) — a MIDI MCP and OSC MCP. Discover devices, read a device's OSC surface, send OSC to synths and DAWs. See docs/MCP.md. Honest provenance. Each device declares its source in _sources[]: ✅ hardware-verified, ✅ software-verified, 📘 vendor-doc, 📡 vendor-osc-api / 📡 third-party-osc, 🎛️ electra-preset, 📦 pencilresearch. You always know whether a mapping was tested on the device or lifted from a spec sheet. Bidirectional out of the box. Incoming MIDI (knob turns, SysEx replies, NRPN) is decoded and re-emitted as OSC. Multi-client fan-out is a --osc-client flag. N-to-N orchestration. One process can drive several synths at once (osc-bridge orchestrate --config bridge.toml), each reachable under its own OSC prefix — so two MatrixBrutes live side-by-side as /matrixbrute-1 and /matrixbrute-2. First-class reconfigurable controllers (Electra One MK2). Upload a generated preset as one OSC call; the bridge parses the JSON, reconfigures the device over SysEx, and dynamically rewires its own CC↔OSC routing so each knob on the new layout is reachable by name. Self-describing over OSC: /bridge/docs returns the integration guide, /electra1/routes/list returns the authoritative address table, so clients (or LLM-driven integrators) never hardcode slugification or protocol details. See § Reconfigurable controllers below. Escape hatch when JSON isn't enough. For devices with checksums, quirky scaling, or stateful protocols, an optional per-parameter transform / per-command script runs Lua 5.4 sandboxed (1 MiB / 10 ms caps, no os/io/loaders). Used sparingly — osc-bridge lint warns on every script use — but it lets the declarative core stay small without giving up on edge cases. See docs/scripting.md. Runtime you can trust. Rate-limiting per device, backpressure-aware, zero-alloc hot path, no GC. Single static binary on Windows / Linux / macOS.
Server Config
{
"mcpServers": {
"osc-bridge": {
"command": "npx",
"args": [
"-y",
"@roomi-fields/osc-bridge",
"mcp"
]
}
}
}