VRGDG_PythonCodeRunner

Every ComfyUI power user eventually hits the wall where the node graph can't express the transform they need - a JSON reshape, some string surgery, a math step - and wishes they could just write a few lines of Python. VRGDG_PythonCodeRunner is VRGameDevGirl's answer: a sandboxed Python node that runs your code on the inputs and hands the result back as a node output.

The key word is sandboxed, and the default code shows it. The comment block at the top of the editor spells out the deal: "Safety mode: imports, filesystem/process/network APIs are blocked." You get a curated set of built-ins - json, math, re, plus your two inputs input_text and input_json - and you set a variable named result. That's the whole API surface.

How it works

One required input:

• python_code - your script. The available vars are listed in the default template: input_text, input_json, json, math, re. Set result to any value before the script ends.

Two optional inputs:

• input_text - a plain string you can feed in.
• input_json - a JSON string, typically a prompt map or scene list from upstream.

Outputs:

• result_text - your result coerced to a string.
• result_json - your result serialized as JSON text.
• has_error - a boolean that flips true if your code raised, so downstream logic can branch on failure.

The default code is a working example: parse input_json, re-serialize it with indentation. Run it once to confirm the plumbing, then replace it.

What it's actually good for

The pack's prompt-map workflow is full of small transforms that are miserable in pure nodes - reordering fields, stripping keys, merging scene lists, regex-cleansing LLM output. Instead of a chain of five string-manipulation nodes, you write one five-line function. It's also handy for debugging: dump json.dumps(input_json, indent=2) to result_text and see exactly what an upstream node produced.

The safety caveat

The sandbox blocks file/process/network access - that's the point, and it's the responsible default given how many compromised custom nodes have shipped in this ecosystem. The trade-off: you can't read a file, write state, or call out to an API from inside it. If you need that, you need a real Python executor, not this node. Read the sandbox block before you trust it with anything sensitive, same as you would any custom node.

Installing it

Part of the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/vrgamegirl19/comfyui-vrgamedevgirl

restart, or ComfyUI Manager → search vrgamedev. No models.

Gotchas

result is the only thing that matters - return statements are ignored. If your output stays empty, check you assigned result. And remember input_json arrives as a string; parse it with json.loads() before treating it as data, exactly like the default template does.