Execution

By default, Live manages the Extension Host process. This means that during development you’d have to relaunch Live for every change to your extension — a significant slowdown in your iteration cycle. Live offers a Developer Mode that lets you take over the Extension Host yourself and reload your extension without restarting Live.

Enable Developer Mode

Open Live’s preferences, navigate to the Extensions tab, and enable Developer Mode. Live will shut down the Extension Host it would normally launch, leaving it to you.

Launch the Extension Host

A new extension project already has scripts for this. From inside your extension’s directory:

npm start

This builds your extension in development mode and launches the Extension Host with the right arguments. It reads EXTENSION_HOST_PATH from .env (filled in during setup) to locate Live’s Extension Host module.

Then npm start in the first terminal will pick up rebuilt code each time you restart it.

Using extensions-cli directly

npm start is a thin wrapper around extensions-cli build --dev && extensions-cli run. You can call the CLI yourself if you want to override settings:

npx extensions-cli run --live "/Applications/Ableton Live 12.4 Beta.app"

Options

• --live <path> — path to Ableton Live (.app on macOS, .exe on Windows, an install root, or a direct path to ExtensionHostNodeModule.node). Overrides EXTENSION_HOST_PATH.
• --storage-directory <path> — directory passed to your extension via context.environment.storageDirectory.
• --temp-directory <path> — directory passed to your extension via context.environment.tempDirectory.
• --inspect — enable VS Code debugging (uses --inspect-brk).

Note

If you don’t pass --live, the CLI reads EXTENSION_HOST_PATH from your environment or from a .env file in the current working directory. The project creator writes this file for you.