Smart JSON Text

SmartJSONText is the odd one out in this pack. Everything else in the Ultimate Auto Sampler Config Grid Testing Suite is about generating and viewing test grids; this node is just a multiline text box that parses and pretty-prints JSON, with inline error display when your JSON is invalid. It lives in the text category, not sampling/testing. If you've only heard of the pack for its sampler grid, this is the node you might stumble on while browsing and wonder about - it's a small utility, but it earns its keep.

What it actually does

You type (or paste) JSON into its json_text input. With validation on, the node parses it and re-serializes it pretty-printed with 2-space indentation. If the JSON is invalid, it leaves your text alone and surfaces the error inline in the widget rather than crashing the graph - which is precisely the failure mode that bites beginners when they hand-edit a workflow file. The parsed_json output gives you a normalized version of the config, so downstream nodes see consistent, formatted JSON instead of whatever spacing you happened to type.

Why would you use it in this suite? Two reasons. First, the generator's configs_json input accepts a raw JSON string, and this node is a comfortable way to keep that config visible and validated without opening an external editor - a JSON error in a big grid config produces a confusing failure halfway through a run, and this catches it before queueing. Second, it's a handy general-purpose JSON helper for any workflow that consumes config blobs: type into SmartJSONText, get clean validated JSON out.

The inputs and outputs

• json_text (required) - the multiline JSON string you're editing. Default is a {"key": "value"} placeholder.
• validate_on_input (optional) - whether to parse and pretty-print as you type. Turn it off and the node just passes text through, though at that point you've removed its only reason to exist.

Outputs: json_text (the raw text, echoed back) and parsed_json (the validated, pretty-printed version). Wire parsed_json into whatever needs clean JSON.

Installing

It ships in the same repo, so it comes along for the ride with the suite:

cd ComfyUI/custom_nodes/
git clone https://github.com/JasonHoku/ComfyUI-Ultimate-Auto-Sampler-Config-Grid-Testing-Suite.git

Restart ComfyUI. Or use Manager and search ComfyUI-Ultimate-Auto-Sampler-Config-Grid-Testing-Suite. No model downloads, no heavy dependencies.

One honest caveat

This is a thin node and the pack doesn't document it at all - the README never mentions it. The tooltip-free info schema plus the pretty-printing behavior in the source are the whole story. It's genuinely useful for the exact moment a malformed config throws a cryptic error, but don't expect it to do more than validate, format, and pass JSON through. For that job it's simple and it works, and sometimes that's exactly what you want.