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Control Surface Studio allows you to build MIDI remote scripts visually, but also supports advanced Python coding for full flexibility. If you’re comfortable with code, you can extend your scripts using your own custom Python logic — directly inside Reactions or externally via the user.py file.

This guide covers the three supported approaches to custom coding in CSS:

• Inline Custom Coding
• Block-Level Custom Coding
• External Custom Coding with user.py

Inline Custom Coding

Inline custom code lets you insert switch a Reaction menu for a text field where you can enter Python snippets. This is ideal for things such as adding a dynamic variable, a method call or performing some math to get the desired value.

Example Use

1. Add an Action (e.g. Set Track Color) using the visual editor.
2. Instead of choosing a static color number, click the custom code icon next to the value field.
3. The field switches to Custom Code, allowing you to type inline Python such as:

   2 + 3

or reference a variable like:

   self.my_color_value

How It Works

• You’re modifying a single value in the action, condition, or listener.
• CSS shows you the generated code (e.g. self.song.tracks[0].color) and updates it live when parameters change.
• This is ideal for small, calculated expressions or variable overrides.

Block-Level Custom Coding

Block-level custom code replaces entire Reactions components — like actions, conditions, loops, or listeners — with raw Python.

How to Use

1. In a Reaction block (e.g. an Action), select Switch to Custom Code.
2. The block will convert from the visual menu to a raw code editor and will display the code version of what ever was selected in the GUI / menus.
3. Enter multi-line Python directly. Example:

   for i in range(4):
       self.log_message(f"Track {i} color: {self.song.tracks[i].color}")

4. You can switch back to the visual menu at any time — it will remember your previous menu configuration.

Use Cases

• Multi-step operations
• Loops or conditionals more complex than the visual tools support
• Custom logging or debugging
• Dynamic control logic across multiple devices or parameters

You can also apply block-level custom code to Conditions, and even create multiple if/elif style blocks by using multiple conditions sections.

External Custom Coding with user.py

For more complex or reusable Python code, you can create a dedicated user.py file and import it into your CSS script.

What Is user.py?

• A standalone Python file you place in your script’s folder.
• Automatically loaded by Control Surface Studio when the script is installed.
• Can contain custom methods, class-level logic, and initialization code.

Setting Up user.py

1. Copy the appropriate user.py file into your CSS script folder. You can download the user.py file from: https://remotify.io/user_py_files/user.py_files.zip

• Ensure it’s the correct version for your installed Ableton Live (e.g. Live 10 or Live 11+).

1. The file typically contains (For Live 11+):

import Live
from _Framework.ControlSurface import ControlSurface

class user(ControlSurface):
  def __init__(self, c_instance):
    super(user, self).__init__(c_instance)
    with self.component_guard():
      # add init code here
      return

  def test_method(self):
    self.log_message("csslog: it works!")

3. Place the user.py file inside the generated midi remote script folder for your script. i.e. if your script is called ‘beginner script’, find the folder css_beginner_script inside Ableton Live’s MIDI Remote Script Folder. (note: you will need to have already generated the script from CSS into Ableton Live).
   How to install midi remote scripts into Ableton Live
4. Back in CSS: In a Reaction action block, switch it to Custom Code, then call your method:

   self.user.my_custom_method()

Calling External Methods with Parameters

You can also pass values into your custom methods:

self.user.my_custom_method("some text", 42)

This allows for highly dynamic behavior and more modular code organization.

Using Modifiers in user.py

Modifiers can be used as dynamic inputs for your external functions.

How to Pass a Modifier to user.py

1. In CSS, set a modifier (e.g. M1) in a Reaction:

   Set modifier M1 to: "Hello World"

2. In a separate Action block, call your method and pass the modifier:

   self.user.my_custom_method(self.get_modifier_value("M1"))

3. In your user.py file:

   def my_custom_method(self, message):
       self.log_message(f"Received from M1: {message}")

Notes

• When calling a Modifier, be sure to use self.get_modifier_value("M1") — not just M1.
• The modifier must be set before the action block that references it.

Summary

Method	Use Case
Inline Custom Code	Small value overrides inside individual fields
Block-Level Custom Code	Full control of a Reaction block (multi-line logic)
User.py External Code	Modular, reusable code that lives outside CSS
Using Modifiers in user.py	Dynamically pass values to external methods via modifiers

Advanced coding in CSS opens up a wide range of possibilities — from reacting to complex conditions to structuring logic that adapts across tracks, devices, or even user interaction.

If you’re comfortable with Python and want to go even further with midi remote scripting and Control Surface Studio, then this is the path forward.