osc-bridge

io.github.roomi-fields/osc-bridgeroomi-fieldsstreamable-httpv0.13.0Scanned 46 minutes ago

OSC ↔ MIDI bridge — 963 synthesizers and DAWs. A MIDI MCP and OSC MCP for controlling them.

13 tools: 1 do something that can't be undone, 7 change things and 5 only read.

Reads private data · 2
Reads text others write · 8
Can send data out · 2
4 findings

Anlyon alternative

8 of these tools change something. Run those as governed actions.

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Tools

Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.

13 tools

Can't be undone 1Sends, pays, publishes or merges: once done, it cannot be taken back.Claude Code: ask

relay_sendPlay or set something on the user's hardware through a relay: give a driver (id or slug) and one of its OSC addresses from list_routes with its arguments (e.g.Reads text others writeCan send data outNo findings
Why it is in this group
- The name "relay_send" says "send": a word for sending, and what is sent cannot be taken back.
- The input takes a statement or command to run (input.code), which can change anything it can reach.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- outboundThe name "relay_send" says "send": it sends or publishes something to other people.
Description, as the server wrote it
Play or set something on the user's hardware through a relay: give a driver (id or slug) and one of its OSC addresses from list_routes with its arguments (e.g. address '/filter/cutoff', args [64]; '/note/on', args [60, 100]) — the server turns it into the right CC, NRPN, note or SysEx message. Or give raw MIDI bytes as hex. Values are the device's own numbers, clamped to the parameter's range. Sending a patch store or memory-writing SysEx overwrites the device: ask the user first.
Annotations the server declares
- destructiveHint: false
- idempotentHint: false
- openWorldHint: true
- readOnlyHint: false
- title: Send through a relay

Changes things 7Creates or changes something that can be changed back.Claude Code: ask

relay_detectFind which devices are connected to the user's machine through a relay: sends the MIDI Identity Request (F0 7E 7F 06 01 F7, changes nothing on the device) to every output and match…Reads text others write1 finding
Why it is in this group
- The description's first verb is "find": a word for reading.
- The input takes a statement or command to run (input.code), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
Findings
- Warn
  The server marks "relay_detect" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":true}; The description's first verb is "find": a word for reading.
  What this check looks for
Description, as the server wrote it
Find which devices are connected to the user's machine through a relay: sends the MIDI Identity Request (F0 7E 7F 06 01 F7, changes nothing on the device) to every output and matches the answers — manufacturer, model, firmware version — against the catalogue. Returns the best driver ids and identity_hex to pass to report_result. Devices that do not answer are only listed by port name.
Annotations the server declares
- idempotentHint: true
- openWorldHint: true
- readOnlyHint: true
- title: Detect devices through a relay
relay_listenListen to what the user's hardware sends through a relay for a few seconds: notes, CC, NRPN, SysEx, decoded.Reads text others write1 finding
Why it is in this group
- The input takes a statement or command to run (input.code), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
Findings
- Warn
  The server marks "relay_listen" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"idempotentHint":false,"openWorldHint":true}; The input takes a statement or command to run (input.code), which can change anything it can reach.
  What this check looks for
Description, as the server wrote it
Listen to what the user's hardware sends through a relay for a few seconds: notes, CC, NRPN, SysEx, decoded. With a device, each CC or NRPN that moved is matched to the driver's OSC addresses — ask the user to move one control on the device while listening to learn which address it is, or to check that the driver's map is right (then record what you saw with report_mapping, so the catalogue learns it).
Annotations the server declares
- idempotentHint: false
- openWorldHint: true
- readOnlyHint: true
- title: Listen through a relay
relay_statusCheck a relay: the user opened https://osc-bridge.roomi-fields.com/connect/ (or ran osc-bridge connect) and gave you its pairing code.Reads text others write1 finding
Why it is in this group
- The name "relay_status" says "status": a word for reading.
- The input takes a statement or command to run (input.code), which can change anything it can reach.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- untrusted-inputThe description's first sentence says "http": it reads web pages, which anyone can write.
Findings
- Warn
  The server marks "relay_status" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
  Matched text
  annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":true}; The name "relay_status" says "status": a word for reading.
  What this check looks for
Description, as the server wrote it
Check a relay: the user opened https://osc-bridge.roomi-fields.com/connect/ (or ran osc-bridge connect) and gave you its pairing code. Returns the MIDI output and input ports of their machine. Nothing is sent to the hardware.
Annotations the server declares
- idempotentHint: true
- openWorldHint: true
- readOnlyHint: true
- title: Relay status
report_mappingTeach the catalogue which MIDI message a control really sends: after the user moved one control on the device (see relay_listen), give the driver address it is (from list_routes) —…Can send data outNo findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
What it can reach
- outboundThe input takes a destination (input.cc): what the tool writes goes there.
Description, as the server wrote it
Teach the catalogue which MIDI message a control really sends: after the user moved one control on the device (see relay_listen), give the driver address it is (from list_routes) — or, for a control the driver lacks, its panel label — and the CC, NRPN or note it sent, with the firmware and the device's Identity Reply when you have them. When several accounts observe the same thing on one firmware the mapping is learned; get_trust shows learned mappings and where they differ from the driver.
Annotations the server declares
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: false
- title: Report what a control sends
report_resultTell the catalogue how a driver behaved on a real device, after testing it: 'works', 'fails' or 'partial', for the whole driver or one OSC address (from list_routes).No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Tell the catalogue how a driver behaved on a real device, after testing it: 'works', 'fails' or 'partial', for the whole driver or one OSC address (from list_routes). Give the firmware version, and the device's reply to the MIDI Identity Request (F0 7E 7F 06 01 F7) as identity_hex when you can: trust is counted per firmware, so a failure on another firmware does not count against the driver, and a report of unknown firmware cannot be placed. Several accounts that agree on one firmware mark the driver usage-verified there; a report that several others contradict is rolled back and puts its account under review. Report only what was actually tested.
Annotations the server declares
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: false
- title: Report a test result
submit_driverContribute a driver for a device the catalogue lacks (or a better one): the full driver file as a JSON object, in the osc-bridge device schema (device.name, device.vendor, device.o…Reads text others writeNo findings
Why it is in this group
- The name "submit_driver" says "submit": a word for a change.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
Description, as the server wrote it
Contribute a driver for a device the catalogue lacks (or a better one): the full driver file as a JSON object, in the osc-bridge device schema (device.name, device.vendor, device.osc_prefix, and cc_params / params / commands / triggers — see https://osc-bridge.roomi-fields.com/DEVICE_JSON_SCHEMA/). It is checked, then merged into the public catalogue by the merge job if it parses, lints and passes the tests, as its own file of source 'agent-contributed'. Say where the data comes from (manual page, tested on the device).
Annotations the server declares
- destructiveHint: false
- idempotentHint: false
- openWorldHint: true
- readOnlyHint: false
- title: Contribute a driver
submit_fixContribute a corrected variant of a driver from what the catalogue learned: where learned mappings (get_trust → mappings, differs: true) disagree with the driver on one firmware, b…Reads text others writeNo findings
Why it is in this group
- The name "submit_fix" says "submit": a word for a change.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
Description, as the server wrote it
Contribute a corrected variant of a driver from what the catalogue learned: where learned mappings (get_trust → mappings, differs: true) disagree with the driver on one firmware, builds a copy of the driver with the learned CC / NRPN numbers, as a new file for that firmware, and queues it for the merge job.
Annotations the server declares
- destructiveHint: false
- idempotentHint: false
- openWorldHint: true
- readOnlyHint: false
- title: Contribute a fix from learned mappings

Only reads 5Looks things up and changes nothing.Show 5 read-only tools

get_contributionWhere a contribution stands: pending (waiting for the merge job), merged (with its pull request), rejected (with the reason), or held (its account is under review).Reads text others writeNo findings
Why it is in this group
- The name "get_contribution" says "get": a word for reading.
What it can reach
- untrusted-inputThe description's first sentence says "pull request": it reads issues, which other people can write.
Description, as the server wrote it
Where a contribution stands: pending (waiting for the merge job), merged (with its pull request), rejected (with the reason), or held (its account is under review).
Annotations the server declares
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: true
- title: Contribution status
get_device_docsFetch the markdown companion documentation for one device, if present.Reads private dataNo findings
Why it is in this group
- The name "get_device_docs" says "get": a word for reading.
What it can reach
- private-dataThe name "get_device_docs" says "get" and "doc": it reads documents.
Description, as the server wrote it
Fetch the markdown companion documentation for one device, if present. The slug is the device's OSC prefix without the leading slash (e.g. 'ableton' for /ableton).
Annotations the server declares
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: true
- title: Get device docs
get_trustHow far a driver has been confirmed by people who used it, per firmware: status (unreported, unconfirmed, usage-verified, firmware-dependent, failing, disputed), how many users rep…No findings
Why it is in this group
- The name "get_trust" says "get": a word for reading.
Description, as the server wrote it
How far a driver has been confirmed by people who used it, per firmware: status (unreported, unconfirmed, usage-verified, firmware-dependent, failing, disputed), how many users report it works / fails / partly works, each firmware's own status, the device identities seen for each firmware, and the same per OSC address. needs_firmware: true means reports disagree and some have no firmware — identify the device before reporting (see learn). Check it before relying on a driver, together with its source_tier.
Annotations the server declares
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: true
- title: Get a driver's trust
list_devicesFind device drivers in the catalogue (about 980 synths, drum machines, controllers and DAWs).No findings
Why it is in this group
- The name "list_devices" says "list": a word for reading.
Description, as the server wrote it
Find device drivers in the catalogue (about 980 synths, drum machines, controllers and DAWs). Without arguments it lists them all; `query` keeps drivers whose vendor, name or slug contain every word (e.g. 'korg minilogue'). Returns name, vendor, OSC prefix (slug), kind, source tier and firmware version when the source states one. Pass the slug to list_routes for the full CC/NRPN/SysEx map.
Annotations the server declares
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: true
- title: List devices
list_routesReturn the OSC routes a device exposes: declarative commands (OSC paths it accepts), cc/nrpn params, sysex params, named note triggers (drum sounds), and reply patterns.Reads private dataReads text others writeNo findings
Why it is in this group
- The name "list_routes" says "list": a word for reading.
What it can reach
- private-dataThe description's first sentence says "return" and "note": it reads notes.
- untrusted-inputThe description's first sentence says "return" and "reply": it reads comments, which other people can write.
Description, as the server wrote it
Return the OSC routes a device exposes: declarative commands (OSC paths it accepts), cc/nrpn params, sysex params, named note triggers (drum sounds), and reply patterns. Use this to discover what a device can do.
Annotations the server declares
- idempotentHint: true
- openWorldHint: false
- readOnlyHint: true
- title: List device routes

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Exfil surface

Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.

32 paths in this server alone from private data, through text someone else wrote, to a way out. Denying 2 outbound tools breaks every one.

Reads private data2: Reads files, mail, messages, databases, secrets, calendars or repositories.; get_device_docs
list_routes
Reads text others write8: Brings in text someone else can write: web pages, inbound email, messages, issues and comments.; get_contribution
list_routes
relay_detect
relay_listen
relay_send
relay_status
submit_driver
submit_fix
Can send data out2: Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.; relay_send
report_mapping

deny to break every path

{
  "permissions": {
    "deny": [
      "mcp__osc-bridge__relay_send",
      "mcp__osc-bridge__report_mapping"
    ]
  }
}

Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.

Findings

Matches of fixed checks, with the text they matched.

3 warn1 info

Warnrelay_status
The server marks "relay_status" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":true}; The name "relay_status" says "status": a word for reading.
What this check looks for
Warnrelay_detect
The server marks "relay_detect" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"idempotentHint":true,"openWorldHint":true}; The description's first verb is "find": a word for reading.
What this check looks for
Warnrelay_listen
The server marks "relay_listen" read-only (readOnlyHint: true), and its own name, description or input give the class "write".
Matched text
annotations: {"readOnlyHint":true,"idempotentHint":false,"openWorldHint":true}; The input takes a statement or command to run (input.code), which can change anything it can reach.
What this check looks for
InfoThe whole server
The package.json has a "postinstall" script, which npm runs on install.
Matched text
scripts.postinstall: "node scripts/postinstall.js"
What this check looks for

History

Changes to its tool definitions and to its remote endpoint, newest first.

No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.

All changes to this server

Install

Pinned to version 0.13.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http osc-bridge https://mcp.osc-bridge.roomi-fields.com/mcp

claude mcp add --transport http osc-bridge https://mcp.osc-bridge.roomi-fields.com/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json

{
  "permissions": {
    "allow": [
      "mcp__osc-bridge__list_devices",
      "mcp__osc-bridge__get_device_docs",
      "mcp__osc-bridge__list_routes",
      "mcp__osc-bridge__get_trust",
      "mcp__osc-bridge__get_contribution"
    ],
    "ask": [
      "mcp__osc-bridge__report_result",
      "mcp__osc-bridge__report_mapping",
      "mcp__osc-bridge__submit_driver",
      "mcp__osc-bridge__submit_fix",
      "mcp__osc-bridge__relay_status",
      "mcp__osc-bridge__relay_detect",
      "mcp__osc-bridge__relay_send",
      "mcp__osc-bridge__relay_listen"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as osc-bridge. Review it before you use it.

Capability tags behind 10 rules

mcp__osc-bridge__get_device_docs private-data
mcp__osc-bridge__list_routes private-data, untrusted-input
mcp__osc-bridge__report_mapping outbound
mcp__osc-bridge__submit_driver untrusted-input
mcp__osc-bridge__submit_fix untrusted-input
mcp__osc-bridge__get_contribution untrusted-input
mcp__osc-bridge__relay_status untrusted-input
mcp__osc-bridge__relay_detect untrusted-input
mcp__osc-bridge__relay_send untrusted-input, outbound
mcp__osc-bridge__relay_listen untrusted-input

Keep the decision: fail CI when the tools change, follow every change, or show a badge.

Pin in CI

Fail a build when the tools you reviewed are not the tools the server serves today.

curl -s "https://anlyon.dev/api/v1/servers/io.github.roomi-fields/osc-bridge/verify?hash=0b6157092de9ff8950143963707cb18cc4ec916fd3474707e7e9dce5702e3b92" | jq -e '.changed == false'

Pinned hash 0b6157092de9, from Oct 23, 2026, 06:18 UTC.

Watch

Get told when its tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/io.github.roomi-fields/osc-bridge/changes.xml

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Badge

[![anlyon.dev](https://anlyon.dev/badge/io.github.roomi-fields/osc-bridge.svg)](https://anlyon.dev/servers/io.github.roomi-fields/osc-bridge)

Source: MCP Registry · repository. Synced Oct 23, 2026, 06:17 UTC.