JSON File Parser🐶

Config files, cached API responses, exported data - a lot of useful stuff sits in JSON files that never touch your ComfyUI graph directly. JSON File Parser is the bridge: point it at a .json file and a key, and it reads the file off disk and hands you back that field's value, ready to wire into the rest of your workflow.

The important distinction inside comfyui_LLM_party's converter family: this node reads from a file path. If your JSON is already in-graph as a string - say, an LLM's structured output - the sibling node JSON Get Value is the one built for that instead.

How it works

Give it file_path and a key, and it opens the file, parses it as JSON, and looks up that key. Two things come back: the whole file's contents as text, and the specific value at your key. Because it's marked as an output node, it also surfaces its result directly on the canvas rather than requiring you to route it somewhere just to inspect it.

The inputs and outputs that matter

• file_path (default data.json) - the JSON file to read.
• key - which top-level field to pull out.
• is_enable - the pack's standard bypass toggle.

Outputs: show_json_file (STRING) - the entire file's raw content, handy for confirming you're reading the file you think you are, and value_by_key (typed *, ComfyUI's wildcard) - the value at your key. That wildcard typing matters: it'll connect to a STRING, INT, LIST, or whatever socket matches what's actually stored under that key in the file, without you needing a separate converter for each type.

How to install it

Search comfyui_LLM_party in ComfyUI Manager and install, then restart. Manual route:

cd ComfyUI/custom_nodes
git clone https://github.com/heshengtao/comfyui_LLM_party.git

Run pip install -r requirements.txt from inside the pack's folder using ComfyUI's own Python, then restart. This particular node is plain file I/O with no dependencies of its own worth mentioning - the heavier install cost in this pack belongs to its LLM, embedding, OCR, and TTS nodes elsewhere, not this one. If those cause version conflicts, the README's requirements_fixed.txt is the pinned-version fallback.

Common issues & troubleshooting

It errors before returning anything. Check file_path first - a relative path resolves against wherever ComfyUI's working directory happens to be, which is a more common mistake than a genuinely missing file. Use an absolute path if you're unsure.

value_by_key comes back empty or wrong. key has to match exactly - case, spelling, the works - against a top-level field in the JSON. If your data is nested (a key inside another object), a plain top-level key lookup won't reach it; check show_json_file first to confirm the actual structure of what you're reading before assuming the node is broken.

The file parses fine elsewhere but fails here. A JSON file with a trailing comma, an unescaped quote, or similar isn't valid JSON even if some editors tolerate it silently - run it through a validator, or through this pack's JSON Repair node, before this one if you suspect the file itself is the problem rather than your key.