Connect your synth to an AI agent¶
This page is SynthHub's relay: it lets an AI agent reach the MIDI devices plugged into this computer, with nothing to install. Your browser talks to your synth; the SynthHub server (built on osc-bridge) turns the agent's requests ("set the filter cutoff to 64", "play middle C") into the right MIDI messages for your device, from a catalogue of 963 drivers.
Not connected. Works in Chrome, Edge, Opera and Firefox; not in Safari.
Your code: ····-····
- In your AI assistant, add a remote MCP server (in Claude: Settings → Connectors → Add custom connector) with this address, once:
- Tell the agent:
- Keep this tab open while you play. Closing it ends the session.
The first agent to use a code is the only one that can drive your devices; a new code ends the session and pairs again.
What happens¶
- The agent asks the server; the server sends MIDI messages to this page, which plays them on your device. Every message appears in the list above as it passes.
relay_detectasks each device who it is (the standard MIDI Identity Request, which changes nothing on it) and finds its driver and firmware.relay_sendsets a parameter or plays a note by its name in the driver.relay_listenhears what your device sends: turn a knob and the agent sees which parameter it is.
Trying it without a synth¶
Tick Add a virtual test synth: the page then offers a simulated device,
Test Synth, alongside your real ones. It
answers relay_detect like a real synth, and sends back everything it
receives, so relay_send followed by relay_listen shows the round trip.
Ask your agent: "Detect my devices, set the Test Synth's cutoff to 90 and
check what it sends back." The same synth is available on the command line
with osc-bridge connect --test-synth.
Privacy¶
The server gives this browser an account — a random id, kept in this browser so you stay the same user next time; no sign-up, no personal data.
Sharing is on by default: the identity (model, firmware) of the devices your agent detects is recorded to improve the catalogue for everyone. Untick Share the identity of my devices to record none, or tick private next to one device to keep only that one out; this browser remembers which devices you made private. Your MIDI messages themselves are never recorded.
The server does not keep your address; like any site, the web server in front of it keeps a short access log for a few days. Details: API for agents.
Limits¶
- Safari and iOS do not give web pages access to MIDI devices; use Chrome or
Edge, or
osc-bridge connecton your computer. - Messages that can overwrite your device — every SysEx message except the Identity Request: patch dumps, stores, settings — are never sent without you. The page shows what the agent wants to send, and nothing goes out until you press Accept. Refuse sends nothing.
- Timing follows the network: fine for setting sounds and playing test notes, not for tightly timed sequences.