Model Checker 💎 Just Nodes

Model Checker is a workflow doctor with a single button. Drop it on any canvas, click check models, and it scans every node in the graph for model-referencing widgets, then reports which referenced files actually exist and which are missing. That's the entire job - no inputs, no outputs, no data flowing through it. It exists to answer the single most common ComfyUI complaint in the community: you load a shared workflow, hit run, and get a wall of "model not found" errors because the author had files you don't.

Mechanically it's a small server-side audit. The node's front-end gathers the widget values from every node on the canvas and POSTs them to the pack's /just_nodes/check_models endpoint. The backend walks each node's declared input types, finds inputs whose options look like model filenames (anything ending in .safetensors, .ckpt, .pt, .pth, .bin, .onnx, .gguf), and compares the widget's current value against the list of available files. The result lands in two places: the button label summarizes (✓ 4 models OK, or ✗ 2 missing, 4 found) and a report textarea on the node lists every missing model with its node ID, node title, and the exact input it belongs to. There's also a debug list for nodes the checker couldn't inspect, which is where the limits start.

The limits are real and worth understanding before you trust it blindly. It only audits nodes whose classes ComfyUI itself knows about (in the core NODE_CLASS_MAPPINGS) - a LoRA loader from another custom pack gets skipped and shunted to debug, not audited. It also only catches values sitting in dropdown widgets at check time, not files that get resolved dynamically at runtime. So treat it as a fast triage for "is my base model actually here," not as a complete dependency audit.

Installing it

Same as every Just Nodes node: ComfyUI Manager → search "Just Nodes" → install → restart, or cd ComfyUI/custom_nodes && git clone https://github.com/Arroz-11/ComfyUI-Just-Nodes.git. No models, no extra dependencies, MIT licensed.

Gotchas

• It's a button, not a node you wire. No inputs, no outputs - if you're looking for something to connect, this isn't it.
• It covers core ComfyUI model loaders only. Custom pack loaders fall through to the debug list.
• It checks dropdown values at click time, so a value that's still empty (nothing selected) is ignored rather than flagged.
• The report is on the node, not in the console - and it's the front-end doing the talking, so if ComfyUI's front-end changes (the Nodes 2.0 rewrite being the big one), this node is exactly the kind that can break silently.