Open the WebSocket to the MuseScore plugin; returns {"success": bool}.

Ping the MuseScore WebSocket API to check the connection.

Also performs a version handshake: the response carries the server version and the plugin's version. If versionsMatch is false, the installed plugin is out of sync with the server - fix with musescore-mcp install-plugin (then restart MuseScore and relaunch the plugin).

Get the full score analysis (metadata, all measures, staves, notes, harmonies).

Get score metadata only (title, composer, measures, staves, time/key signatures).

Get the current cursor position, the selection and a score summary.

Process a sequence of documented plugin actions.

Each entry is {action, params}; the available actions, their parameters and return shapes are specified in docs/ACTIONS.md. Sequences may nest one level (a processSequence action inside a sequence); edit actions are wrapped and rolled back per action.

Execute QML/JavaScript code inside the MuseScore plugin and return its result.

For complex score tasks that would otherwise need many round trips. The code is a function body, run as function(ctx, params, state):

• ctx: plugin API facade - ctx.score (current Score), ctx.newCursor(), ctx.processCommand({action, params}), ctx.processElement(element), ctx.getScoreSummary(), ctx.getVoices(params), ctx.log(msg)

• params: the params object of this call (yours to shape)

• state: object persisting across run_qml calls (for multi-step work; mutate it, do not reassign it) The return value must be JSON-serializable (checked before commit). Undo-aware engraving changes in a run form one undo step; errors roll them back, including nested ctx actions. Playback/mixer actions, undo and recursive eval are rejected inside a run. Raw native writes bypassing MuseScore's undo stack (such as setMetaTag) are outside this guarantee. Call get_score before and after a run when you want your own before/after comparison - the server itself keeps no state. The code runs on MuseScore's GUI thread - an infinite loop freezes MuseScore unrecoverably. See docs/AGENT-COOKBOOK.md for patterns and known pitfalls. Requires the plugin property allowEval: true; otherwise returns an error explaining how to enable it.