create-extension

Create Extension Workflow

Use the create_extension MCP tool to create a fully-wired TD extension:

create_extension(
    parent_path='/path/to/parent',
    class_name='MyFeatureExt',
    name='MyFeature',           # Optional: COMP name
    code='...',                 # Optional: initial Python code
    promote=True,               # Optional: promote extension methods
    ext_name='MyFeature',       # Optional: extension name
    ext_index=0                 # Optional: extension index
)

This creates: baseCOMP + text DAT + extension wiring, initialized and ready to use.

Extension Lifecycle Methods

Always implement these in your extension class:

class MyFeatureExt:
    def __init__(self, ownerComp: COMP) -> None:
        self.ownerComp = ownerComp

    def onDestroyTD(self) -> None:
        """Called on old instance before TD reinitializes. Clean up callbacks, timers, etc."""
        pass

    def onInitTD(self) -> None:
        """Called at end of frame after init. Safe to access other extensions and cooked network."""
        pass

Naming Convention

Extension classes and source DATs must follow the NameExt convention:

• Class: MyFeatureExt
• DAT: MyFeatureExt (matches class name)

Three Namespace Tiers

TD promotes every capitalized member -- methods and class constants alike. There is no per-member opt-out, so the capital letter is the access modifier. Pick the tier by who calls it:

Tier	Name	Reached as	Who calls it
1. Public API	UpperCamelCase	op.MyFeature.DoSomething()	A user or an agent, deliberately
2. Wiring	lowerCamelCase	op.MyFeature.ext.MyFeature.onFrame()	The COMP's own exec / callback / parexec DATs
3. Private	_lowerCamelCase	inside the class only	The class itself

Test: could a user or an agent reasonably call this ON the COMP? If not, it is not tier 1. Promoting a frame hook is a design flaw, not a shortcut.