Extending Protocol 0

Protocol 0 is built to be extended. There are three ways to add your own behavior:

• Add a smart action — drop in a small file and get a new action you can bind to a shortcut. The simplest path.
• Call the HTTP API — drive Protocol 0 from your own tools over a REST API.
• Write a plugin — full control over Ableton UI - for the brave.

Add a smart action

A smart action is the easiest way to add a new action: a tiny .py file you drop into Protocol 0's plugins folder. On Windows that's:

C:\ProgramData\Ableton\Live 12 Suite\Resources\MIDI Remote Scripts\Protocol_0\protocol0\plugins\

Start from the example, which includes comments and a working action you can copy and adapt: the example plugin on GitHub. A smart action is a small plugin with a single @action method — the method name is the action, and its typed parameters become the inputs:

from protocol0.application.plugin.PluginInterface import PluginInterface
from protocol0.application.plugin.action import action
from protocol0.shared.logging.StatusBar import StatusBar


class HelloPlugin(PluginInterface):
    name = "hello"                       # the namespace shown in the shortcut UI

    @action
    def hello(self, name: str) -> None:  # method name = action; params = inputs
        StatusBar.show_message("Hello %s!" % name)

Save the file, restart Ableton, and hello appears in the shortcut UI at http://127.0.0.1:9010/shortcuts — bind it to any combo.

Full reference on GitHub.

Call the HTTP API

When Ableton is open, Protocol 0 exposes a REST API on your machine — the same calls a keyboard shortcut makes under the hood. Any tool that can send an HTTP request (a script, a Stream Deck, your own app) can drive Live through it.

The full, always-up-to-date list of endpoints — with parameters and a try-it-out button — is in the interactive Swagger UI:

http://127.0.0.1:9010/api-docs/index.html

• Localhost only — the server binds to 127.0.0.1, so it's never reachable from the network.

Write a plugin

If you want full flexibility you write a plugin. Coding a plugin is like coding a remote script, except you can use methods and classes from Protocol 0 — so it might be simpler than starting from scratch :)

Like smart actions, plugins are Python files and are discovered automatically — you subclass PluginInterface, declare what you listen to and what you expose, and the script wires it all up.

Full reference on GitHub.