JSON OutputList

JSON OutputList is the pack's Swiss-army knife for anything structured: API responses, config files, workflow metadata, even literal arrays you want to sweep. It extracts values from a JSON object with a JSONPath query and flattens every match into one output list, so downstream nodes run once per extracted value.

It's built on jsonpath_ng, the standard Python JSONPath library, so the query syntax is the familiar $.dict, $.arr[*], $..value style. The mechanism is worth knowing: each match gets flattened into a single long list. A matched object's keys become entries, a matched array's elements become entries, scalars become a single entry - all merged in order, and the count output tells you how many you ended up with.

The inputs

• jsonpath - the query, e.g. $.dict. Default $.dict comes pre-filled.
• json - a JSON string (multiline box). A default sample object ships with it.
• obj - optional wildcard input that replaces the JSON string entirely. This is the sneaky-powerful one: feed it any node's object output and query that instead of a pasted string.

Outputs are key (dictionary keys or array indices, as strings), value (the values as strings), int and float (parsed numbers, defaulting to 0 when unparseable), count, and debug - a pretty-printed JSON of every matched object, invaluable when a query returns nothing and you need to see why.

The use case that justifies it

The pack's flagship pattern: Load Any File.metadata → JSON OutputList with jsonpath=$.["PNG:Prompt"]. ComfyUI embeds the full workflow JSON in every PNG it saves, so you can load a batch of saved images, extract each one's prompt, and re-run or iterate them. That's how the Workflow Discriminator node recovers the exact prompt behind each image in a grid. You can also use it standalone with literal strings: [1, 2, 3] as json with jsonpath=$ gives you an instant number list when Number OutputList's ranges don't fit.

Installing

Search "OutputLists Combiner" in ComfyUI Manager, or clone into ComfyUI/custom_nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/geroldmeisinger/ComfyUI-outputlists-combiner
cd ComfyUI-outputlists-combiner
uv pip install -r requirements.txt

Restart after. jsonpath_ng is one of the lighter deps in the pack's requirements - no models, no binaries. If a JSONPath returns empty, check debug first: a malformed path silently yields zero matches, and debug showing [] tells you it's the query, not the data.