Building a stripped-down Live template (`als-template.mjs`) #

Live 12's stock "New Live Set" hands you 2 MIDI + 2 audio + 2 return tracks. The fleet wants a genuinely blank Set — one input channel + the Main out, nothing else. Live has no CLI for that, and its UI can't always be driven (a locked Mac has no UI, and Live throws blocking modals), so we shape the .als directly.

node als-template.mjs                                  # 1 audio + Main, no MIDI, no returns
node als-template.mjs --audio 1 --midi 0 --returns 0 --out AC-Blank.als
node als-template.mjs --xml-out AC-Blank.xml           # also emit the XML to read

Format #

An .als is gzipped UTF-8 XML rooted at <Ableton><LiveSet> — see docs/ableton-als-structure.md. The repo already reads .als three ways (saxes here, pako/JSZip in bios.mjs, native DecompressionStream + regex in wipppps.mjs); this is the only thing that writes one.

live-12-blank.xml is a stock blank Set, already decompressed — the base we carve from.

What the strip has to get right #

Removing whole <MidiTrack> / <AudioTrack> / <ReturnTrack> elements is most of the job, but one invariant is easy to miss: every track carries one <TrackSendHolder> per return track. Drop the returns without truncating each surviving track's <Sends> and the Set is inconsistent. With zero returns, every <Sends> must be empty.

Everything else is self-contained, which is what makes this safe:

TracksListWrapper / VisibleTracksListWrapper / ReturnTracksListWrapper / SendsListWrapper are empty LomId="0" stubs — they do not enumerate track IDs, so there is nothing to renumber.
The stray Id="12"/"13"/"14" hits elsewhere in the file are device-macro locals (ModulationTarget, NamedRemoteableKeyMidi), not track references.
<SendsPre> and <SendsListWrapper> are left alone — matching on the exact string <Sends> (with the closing angle bracket) never catches them.

Verify by opening it #

Hand-built XML is only correct if Live agrees. Open the result in Live — it should load with exactly the requested tracks and no repair prompt. (Confirmed for the 1-audio/0-MIDI/0-return default.)

Note the base is Live 12.2.1 schema (MinorVersion="12.0_12203"); 12.4.2 opens it fine and re-serializes on save.

Installing it #

toolchain/macos/fleet/ableton-template.mjs builds this and drops it in each fleet Mac's ~/Music/Ableton/User Library/Templates/, so it shows up in Live's browser under Templates > AC Blank — one click to a genuinely blank Set.

click menu item "Save Live Set As Default Set..." silently invokes the WRONG command. It reports success, but what actually fires is "Save Live Set As Template…", the item immediately above it in the File menu. That is why every attempt merely dropped a file into User Library/Templates/ and popped a rename field, and why ⌘N never changed.

Press it by index instead — item 17 of the File menu (16 is the Template item):

tell application "System Events" to tell process "Live"
  perform action "AXPress" of menu item 17 of menu 1 of menu bar item "File" of menu bar 1
end tell

With the stripped Set open, that press did the real thing: Live came back with a Set whose entire mixer was Audio + Main. Not yet verified across a Live restart — that check is the one thing between this and a fleet-wide installer.

Do NOT trust click menu item "<name>" for Live's File menu generally; verify by index and confirm the effect, because a wrong-but-adjacent command is worse than an error.

The default Set is a file — and the FILENAME is the whole trick #

~/Library/Preferences/Ableton/Live <ver>/BaseFiles/DefaultLiveSet.als

That is the Set New Live Set (⌘N) opens. DefaultLiveSet is one of the strings in the Live binary, and the file turned up for real on neo (which had a hand-made default). ableton-template.mjs --default installs there, backing up any existing default first.

Copies named anything else are ignored no matter where they sit — that is what made this so slippery. Template.als also appears in the binary but is a red herring for this purpose; dropping one into User Library/, User Library/Templates/, User Library/Defaults/, Preferences/Live <ver>/, or BaseFiles/ changes nothing (all checked across full Live restarts). BaseFiles/ is otherwise just where Live copies a Set opened from outside the User Library.

No pointer is written to Preferences.cfg — no .als path, no default key. It is purely this file.

Still unverified: installing DefaultLiveSet.als has not been confirmed to change ⌘N across a restart. Launch Live, press ⌘N, count the tracks.

Building a stripped-down Live template (als-template.mjs) #