Quickstart

Two flavors: scripting (one-shot reads/writes) and an extension (lives in Live's right-click menus). Make sure Live is open with the Bridge installed first.

Scripting: read & write the Set

Connect, do something, done. Great for batch jobs and experiments.

from ableton_extensions import connect

app = connect()
song = app.song

print("Tempo:", song.tempo)
print("Tracks:", [t.name for t in song.tracks])

# write a 4-note MIDI clip on the first MIDI track
from ableton_extensions import MidiTrack, NoteDescription
track = next(t for t in song.tracks if isinstance(t, MidiTrack))
clip = track.create_midi_clip(0.0, 4.0)
clip.name = "Made in Python"
clip.notes = [NoteDescription(pitch=60+i, start_time=i, duration=0.5, velocity=100) for i in range(4)]

app.close()

Run it: python my_script.py. Switch Live to Arrangement view (Tab) and you'll see the clip.

An extension: add a right-click action

This is the real point of the SDK. Save as my_ext.py:

import random
from ableton_extensions import Extension, MidiClip

app = Extension("My Tool", author="you", version="0.1.0")

@app.context_menu("MidiClip", "Humanizer")
def humanize(clip: MidiClip):
    notes = clip.notes
    for n in notes:
        n.velocity = max(1, min(127, n.velocity + random.randint(-12, 12)))
    clip.notes = notes
    print(f"Humanized {len(notes)} notes")

if __name__ == "__main__":
    app.run()

Run it:

ableton-ext run my_ext.py

[My Tool] connected to bridge 0.0.4. 1 menu action(s) registered. Ctrl+C to stop.

Now in Live, right-click a MIDI clip → you'll see Humanizer. Click it and your Python function runs against that clip.