Reusable components

A network you built with tdmcp is great for one show — but to reuse it across projects you want three things: knobs to tune it, behavior you can call by name, and a single .tox file you can drop anywhere. Three tools cover the full story:

Step	Tool	What it does
Build	(any generator)	Make the network — e.g. a feedback tunnel.
Knobs	add_custom_parameters	Append a custom-parameter page (sliders, toggles, menus, pulses, RGB/XYZ).
Behavior	scaffold_extension	Give the COMP a Python extension class with methods you can call.
Package	manage_component	Save the COMP as a reusable .tox (or load one back, live-linked).

You can drive every step in plain language. Here's the whole arc.

1. Build the network

"Create a feedback tunnel from noise with blur and displace, wrap it in a container, and show me a preview."

Say the container landed at /project1/tunnel. Everything below tunes that COMP so it becomes a self-contained, reusable widget.

2. Add knobs (add_custom_parameters)

"On /project1/tunnel, add a 'Controls' page with a Feedback knob (0–1, default 0.9), a Zoom knob (0.5–2), a Spin knob (−180 to 180) and a Reset pulse."

This appends a custom-parameter page so the component exposes a clean control surface instead of forcing the next user to dig into the internal nodes. An existing parameter is skipped with a warning, never overwritten, so re-running it to add one more knob is safe.

Bind the knobs to the work

The knobs are just inputs until you point them at something. Ask to "bind the Feedback knob to the feedback level's brightness" (that's create_control_panel / create_macro under the hood), or read them from the extension class you'll add next.

3. Add behavior (scaffold_extension)

Knobs hold values; an extension class gives the component real methods:

"Scaffold an extension class TunnelExt on /project1/tunnel with methods Reset and Randomize, and promote it."

That creates a Text DAT inside the COMP holding:

class TunnelExt:
    def __init__(self, ownerComp):
        self.ownerComp = ownerComp

    def Reset(self):
        pass

    def Randomize(self):
        pass

…wires it into the COMP's extension slot and promotes it, so the methods are callable straight off the component — op('/project1/tunnel').Reset(). Fill in the stubs (ask the AI, or edit the DAT) and the component now does things, not just holds values.

Promoted = callable by name

Promoted members (capitalized, like Reset) are reachable directly on the COMP. The extension parameter names live on the COMP's built-in Extensions page; tdmcp probes for them so it keeps working across TouchDesigner builds.

4. Save it as a .tox (manage_component)

"Save /project1/tunnel as /Users/me/td-components/tunnel.tox."

Now you have a single file that carries the network, its knobs and its extension class. Drop it into any project:

"Load /Users/me/td-components/tunnel.tox into /project1 as a live-linked instance."

A live-linked instance (externaltox) re-reads the file whenever it changes, so fixing the component once updates every show that uses it.

The same thing from the shell

Every step has a tdmcp-agent command, so you can package a component in a script:

# 2. knobs
tdmcp-agent add-params --params '{
  "comp_path": "/project1/tunnel",
  "page": "Controls",
  "params": [
    { "name": "Feedback", "type": "Float", "default": 0.9, "min": 0, "max": 1 },
    { "name": "Reset", "type": "Pulse" }
  ]
}'

# 3. behavior
tdmcp-agent scaffold-ext --params '{
  "comp_path": "/project1/tunnel",
  "class_name": "TunnelExt",
  "methods": ["Reset", "Randomize"]
}'

# 4. package
tdmcp-agent component --params '{
  "action": "save",
  "comp_path": "/project1/tunnel",
  "file_path": "/Users/me/td-components/tunnel.tox"
}'

Where to go next

• Prompt cookbook — ready-made prompts for building the network you'll turn into a component.
• Tools reference — the full input schema for add_custom_parameters, scaffold_extension and manage_component.