touchdesigner-mcp

Model Context Protocol (MCP) server that lets Claude drive a running TouchDesigner instance — create operators, wire them together, set parameters, run arbitrary Python, and introspect the td API.

Architecture

Claude (MCP client)  ──stdio──►  touchdesigner-mcp (Python)  ──HTTP POST──►  Web Server DAT  ──►  td.run()  ──►  main-thread eval/exec

The MCP server is a thin stdio bridge. All TD mutation happens on TouchDesigner's main thread via a Web Server DAT callback that execs or evals the code you send.

Prerequisites

• TouchDesigner (any recent 2022+ build — tools introspect the live API)
• Python 3.10+
• uv or plain pip

Install via .mcpb (recommended)

The .mcpb bundle is a single-file install for Claude Desktop. It vendors the Python deps and ships the TD-side .tox alongside, so both halves come from one file.

1. Build the bundle from the repo root:

   bash scripts/build_mcpb.sh
   # → built dist/touchdesigner-mcp.mcpb

2. Double-click dist/touchdesigner-mcp.mcpb. Claude Desktop opens a config form — defaults are fine for local TD (TD_HOST=127.0.0.1, TD_PORT=9980, TD_PATH=/mcp). Leave the multi-instance fields blank unless you're targeting more than one TD process. Click Install.
3. Continue with the TouchDesigner-side setup below, then skip the "MCP client configuration" section (the bundle wires that for you).

Requires python3 on PATH (default on most macOS/Linux installs; install from python.org if missing).

Install from source

git clone https://github.com/mrinalghosh/touchdesigner-mcp
cd touchdesigner-mcp
uv venv
source .venv/bin/activate
uv pip install -e .

This exposes a touchdesigner-mcp console script inside .venv/bin/.

TouchDesigner-side setup (one-time, per .toe)

1. Open your project in TouchDesigner.
2. Drag td_component/touchdesigner_mcp.tox into /project1 (or any persistent COMP). The component ships a pre-wired Web Server DAT on port 9980 with the callbacks already attached.
3. Save the .toe.

Manual setup (if you'd rather not use the .tox)

1. Inside /project1 create a Web Server DAT (suggested name: mcp_webserver).
2. Set Port = 9980, Active = On.
3. Replace the auto-created Callbacks DAT contents with td_component/webserver_callbacks.py.
4. Save the .toe.

Verify from a terminal:

curl -s -X POST http://127.0.0.1:9980/mcp \
  -H 'content-type: application/json' \
  -d '{"code": "_result = app.version", "mode": "exec"}'
# → {"ok": true, "result": "2023.xxxxx"}

Or run the packaged smoke test with TD open:

uv run python scripts/smoke_test.py

MCP client configuration

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) — single-instance form:

{
  "mcpServers": {
    "touchdesigner": {
      "command": "/absolute/path/to/touchdesigner-mcp/.venv/bin/touchdesigner-mcp",
      "env": {
        "TD_HOST": "127.0.0.1",
        "TD_PORT": "9980"
      }
    }
  }
}

Multi-instance form (target several TD processes from one Claude session):

{
  "mcpServers": {
    "touchdesigner": {
      "command": "/absolute/path/to/touchdesigner-mcp/.venv/bin/touchdesigner-mcp",
      "env": {
        "TD_INSTANCES": "main=127.0.0.1:9980,fx=127.0.0.1:9981,stage=192.168.1.40:9980",
        "TD_DEFAULT_INSTANCE": "main"
      }
    }
  }
}

Restart Claude Desktop after editing.

Claude Code CLI

claude mcp add touchdesigner /absolute/path/to/touchdesigner-mcp/.venv/bin/touchdesigner-mcp \
  --env TD_INSTANCES=main=127.0.0.1:9980,fx=127.0.0.1:9981 \
  --env TD_DEFAULT_INSTANCE=main

See claude_desktop_config.example.json for both forms in one place.

Environment variables

Var	Default	Purpose
TD_HOST	127.0.0.1	Single-instance host
TD_PORT	9980	Single-instance port
TD_PATH	/mcp	HTTP path the Web Server DAT answers on
TD_INSTANCES	—	Multi-instance map: name=host:port[/path],... (overrides the single-instance vars)
TD_DEFAULT_INSTANCE	first in map	Which instance unqualified tool calls target
TD_TIMEOUT	10.0	HTTP timeout in seconds

Per-instance path override: TD_INSTANCES="main=127.0.0.1:9980/mcp,dev=127.0.0.1:9981/mcp-dev".

Tools

Every tool accepts an optional instance argument to target a specific TD process. Omit it to hit TD_DEFAULT_INSTANCE.

Meta

• list_instances — show configured TD processes
• ping / ping_all — health check

Arbitrary code

• exec_python(code) — runs on TD's main thread; assign to _result to return a value
• eval_python(expression) — single-expression eval

Node lifecycle

• create_operator(parent_path, op_type, name)
• delete_operator(path)
• rename_operator(path, new_name)
• move_operator(path, x, y)

Parameters

• set_parameter(path, param, value)
• get_parameter(path, param)
• list_parameters(path)
• pulse_parameter(path, param)
• bind_parameter_expression(path, param, expression) — switch a parameter to Expression mode with verification (reports any eval exception or new op error)

Wiring

• connect_operators(source_path, target_path, source_output=0, target_input=0)
• disconnect_input(path, input_index=0)

Query

• list_children(comp_path)
• find_operators(root_path='/', op_type=None, name_pattern=None, depth=4)
• get_errors(path='/', recurse=True)

Templates (multi-op recipes that encode known gotchas)

• list_templates — discover available templates and their options
• create_from_template(template, parent_path, name_prefix, options=None) — instantiate one. Ships with chop_source_with_null, glsl_top_vec4_uniform, audio_in_with_analyze, feedback_loop_top, render_pipeline.

Introspection (lets the model discover the live td API rather than guessing)

• get_td_info — version, project, Python, platform
• get_td_classes(name_contains=None)
• get_td_class_details(class_name)
• get_module_help(name)

Example prompts

"Under /project1, create a Noise TOP called n1 and a Level TOP called lvl1, wire n1 → lvl1, then set lvl1.Brightness to 0.6."

"List every TOP under /project1 and report which ones have errors."

"Show me td.noiseTOP's parameters so I know what I can tweak."

Security

The Web Server DAT callback executes arbitrary Python against your live project. Bind it to 127.0.0.1 only, never expose the port to the internet, and don't run untrusted prompts against a TD instance with valuable state open.