OpenOutpainter Serving Checkpoints List

openOutpaint has a checkpoint dropdown, and by default it has no idea what your ComfyUI has installed. This node is how you tell it. OpenOutpainter Serving Checkpoints List builds the list of model names that the canvas's dropdown shows, and the API serves it up whenever openOutpaint asks for /sdapi/v1/sd-models.

The name is a mild lie, by the way - "Model" in the classname is legacy, per the source comments; the display name says Checkpoints, and that's what it actually is. It's a dead-simple node: one multiline string input, one output, no magic.

• checkpoint_names (STRING, multiline) - one checkpoint name per line. These are what show up in the canvas dropdown. Use names you'll recognize; more importantly, use names your Checkpoint Switch node will match (more on that below).
• oop_checkpoints (optional, in) - lets you chain multiple Define nodes, each contributing its lines to a growing list.
• oop_checkpoints (out) - the accumulated list, wired into the Serving node's optional oop_checkpoints input.

Mechanically it's almost boring: it splits the input on newlines and extends the list, skipping any name that's already in it. Same-name entries don't duplicate; chained nodes merge.

The important caveat

This node only populates the dropdown. It does not load or select any model, and the Serving node doesn't load models either. When a user picks a checkpoint in the canvas, openOutpaint stuffs the chosen name into the request's checkpoint field - and then it's up to your workflow to do something with that name. That's what the Checkpoint Switch node is for: it reads the request's checkpoint field, compares it against what you're looking for, and routes the job to the branch that loads the right model. So the practical pattern is: define a few named checkpoints here, build a loader branch per checkpoint, and let the Switch route between them.

Install and gotchas

Standard pack install: ComfyUI Manager (search "OpenOutpaint ComfyUI Interface") or git clone https://github.com/without-ordinary/openoutpaint_comfyui_interface into ComfyUI/custom_nodes, restart. Only opencv-python in requirements, no model downloads.

Gotchas are mostly naming discipline. If the names here don't exactly match what your Checkpoint Switch compares against (or your regex), users will pick a model in the canvas and the graph will silently route to the wrong branch - or block. Keep the list short and intentional; a 40-checkpoint dropdown you never route is just noise. And remember the pack rule: one serving workflow at a time, so keep this node's output wired to a single Serving node.