List Studio One songs on disk (newest first), from ~/Documents/Studio One/Songs or $STUDIO_ONE_SONGS.

Read a Studio One song from its .song file: tempo, time signature, markers, arranger sections, tracks with takes/clips (bar, beat and seconds), mixer channels with volume/pan/mute/solo and plug-in inserts, and media files. Reflects the last save, not unsaved edits.

List a song's autosaves and backups in its History folder (newest first). Each path can be passed to song_read to compare versions.

Is a running Studio One reachable through the MCP Bridge device? Explains how to fix it if not.

List the mixer channels of the song open in Studio One right now, with live volume, pan, mute, solo and record-arm.

Change one mixer channel in the running Studio One. Values are Studio One normalised values (volume/pan 0..1, pan 0.5 = centre; mute/solo/recordArmed 0 or 1). Returns before/after.

The song open in Studio One right now: title, transport (playing, recording, loop, position, tempo, loop range, precount, preroll), track count and selected tracks. Unlike song_read this includes unsaved changes.

Tracks of the song open in Studio One right now, with media type, colour, mixer channel, number of takes, selection, and (by default) their events: name, start/end/length in seconds, muted.

Select a track by exact name in the running Studio One, so that selection-based commands (live_command) act on it. Replaces the selection unless exclusive is false.

Press a transport button in the running Studio One and return the resulting transport state.

Set transport values in the running Studio One: tempo (bpm), playhead position (seconds), loop / precount / preroll on or off. Returns the resulting transport state.

Markers of the song open in Studio One right now: number, position (seconds and bar display) and name (from the last save). Briefly moves the playhead to read them and puts it back; refuses while playing. Only markers 1-20 are visible.

Add a marker in the running Studio One at a position in seconds (default: the playhead). The playhead is left where it was.

Delete a marker in the running Studio One, by number (from live_markers) or by exact position in seconds.

Select all events on the named track(s), or on every track, or clear the event selection. Then use live_command for selection-based edits, e.g. Event/Mute Events, Event/Unmute Events, Event/Toggle Mute, Edit/Split at Cursor, Event/Quantize, Event/Transpose Events Up, Track/Activate Next Layer (switch takes), Edit/Undo.

Set the loop range in the running Studio One (start/end in seconds or as bars like "9.1.1.0"), and optionally turn looping on or off. Returns the transport state.

A track's takes (layers) in the running Studio One: list them, switch to the next/previous take, or unpack all takes to separate tracks. Returns the number of takes and the names of the clips now playing. Takes do not wrap: next on the last take (or previous on the first) changes nothing.

Save the song open in Studio One (File/Save), or save it as a new version (File/Save New Version) to keep the old one.

Undo the last edit(s) in the running Studio One.

Redo edit(s) in the running Studio One.

Toggle a track's arm / monitor / mute / solo, hide it, or duplicate it, by track name; showAll unhides every track. Returns the track's mixer channel afterwards. The track selection is restored. Mute is not on Studio One's undo stack: revert it by toggling again, since live_undo would undo the edit before it.

Edit all events on one track in the running Studio One: mute, unmute, toggleMute, quantize, transposeUp/Down (instrument parts), split / trimStart / trimEnd at a time (seconds or bars), merge, delete. Returns the track's events afterwards. Use live_undo to revert.

Add a track to the song open in Studio One: audioMono (default), audioStereo, instrument, folder or automation.

Peak meters of every mixer channel in dB (-144 = silence). With duration_ms, samples repeatedly (e.g. while playing) and returns the highest peak per channel, plus which channels clipped (above -0.1 dB).

Run any Studio One command by category and name, exactly as listed in Studio One → Keyboard Shortcuts (e.g. Transport/Start, Transport/Stop, Transport/Record, Edit/Undo, File/Save, View/Console). Use live_list_commands to discover names. With check_only, only reports whether the command is currently enabled, without running it.

List Studio One commands available to live_command (about 1,000 on Studio One 5), optionally filtered by a substring. with_state adds whether each is enabled right now; many need a selection or an open editor.

Run JavaScript inside Studio One's script engine and return the result (host objects are described to a depth). Globals: Host, PreSonus, component, describe. Only works when the bridge was installed with --allow-eval. Useful for exploring the undocumented object model, e.g. Host.Objects.getObjectByUrl('://studioapp/DocumentManager'). Do not throw, and check that a host member exists (typeof) before calling it: either one pops a modal Scripting Error dialog in Studio One.