[ ONE-OFF / OP-1 JAM ]

OP-1 Jam

Claude writes the notes. Your OP-1 plays them.

  1. Plug in your OP-1. The Mac app finds it over USB.
  2. Claude writes a loop. Bass, chords or drums, on whatever sound you pick.
  3. Play along, layer up. Claude answers what you play and writes around what’s on tape.

It shows you which keys to press.

Getting started plays each step on a 3D OP-1: hold shift, press COM, press T1. For the cable, the power switch and your headphones it turns to the right-hand end. Drag it round to look.

The app's 3D OP-1, seen from the front left: speaker, volume knob, screen, the four encoders and the keyboard
The 3D OP-1 from above, every key in its place
Every key where it is on yours
The right-hand end of the 3D OP-1: power switch, mini USB, the red line-in jack and the grey headphone jack
Power, USB, line in, headphones
Get it on GitHub →FREE · OPEN SOURCE · MACOS

OP-1 is a trademark of teenage engineering. Not affiliated with teenage engineering or Anthropic. The video is staged, and Claude’s replies are sped up. The OP-1 renders are our own model, not teenage engineering’s artwork. © 2026 One-Off Dev Inc. · MIT licensed.