Connect an AI assistant to Cymasphere

Connect Cursor or Claude Desktop to Cymasphere in a few minutes. Cymasphere must be open and licensed. Your assistant then drives the app while you listen and decide what stays.

Quick setup

1. Open Cymasphere (standalone window open, or the plugin with its editor open).
2. Open the profile menu, then Global Settings. In AGENT, click Copy on the local address. It looks like http://127.0.0.1:54321/mcp with your port number. Use 127.0.0.1, not localhost, on Windows.
3. Add that address to your AI client (Cursor or Claude below). Replace PORT with the digits from that row.
4. Reload the client if it asks, then send a test prompt in the next section.

Only one standalone copy listens at a time. The plugin uses a different port than standalone. Copy the address from the window you want the assistant to control.

Cursor

In .cursor/mcp.json (project) or your user MCP settings, add:

{
  "mcpServers": {
    "cymasphere": {
      "url": "http://127.0.0.1:PORT/mcp"
    }
  }
}

Reload MCP servers in Cursor.

Claude Desktop

Claude needs a small bridge. Edit claude_desktop_config.json (Windows: %APPDATA%\Claude\; macOS: ~/Library/Application Support/Claude/). Replace PORT with your port from AGENT.

{
  "mcpServers": {
    "cymasphere": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "http://127.0.0.1:PORT/mcp",
        "--allow-http"
      ]
    }
  }
}

Quit Claude Desktop fully and open it again.

ChatGPT connectors need a public HTTPS URL. They cannot reach Cymasphere on your computer.

Try it

With Cymasphere in front of you and the client connected, paste:

"Set the key to D minor, generate a progression, then audition the third voicing."

You should see the key change, chord blocks appear, and hear the voicings. Keep what you want, change a chord, or undo the rest. For what the assistant can and cannot do, see AI music composition tools that leave the music to you.

If it does not connect

• No address in AGENT: Cymasphere is not licensed or not listening. Open a licensed copy with its window (or plugin editor) open.
• Address changed: If the port was busy, Cymasphere picks a new one. Copy the row again and update your client config.
• Plugin: The editor must stay open while you connect.
• Second standalone: Only the first copy listens. Close the extra window or use the copy that shows an address.
• Mixer in the plugin: Level and effect changes work in the standalone app, not in the plugin host.

Optional Follow the screen as the agent works in AGENT moves the view when the assistant edits. Leave it off if you prefer to steer the screen yourself.

Another computer on your network

Warning: There is no password. Anyone on the network who has the address can control the app. Use this only on networks you trust, never on public Wi-Fi.

In AGENT, copy the second row (your LAN IP, same port) instead of 127.0.0.1. Paste that full URL into Cursor or mcp-remote the same way as above.

Written for Cymasphere 2.1.10 (agent protocol revision 2026-07-28).