ExtendModelList

ExtendModelList concatenates MODEL lists into a single list, in order. It's the least-used member of bmad4ever's Extend*List family, because there aren't many nodes that consume a list of loaded models - but when you're looping over checkpoints, it's the node that lets a single list carry the whole roster.

Why you'd reach for it

Model lists show up when you want to compare generations across checkpoints, or when a custom node (or a loop you built yourself) is designed to iterate over several models without you manually copying the sampler chain. Instead of wiring one loader into a duplicated chain per checkpoint, you collect all the models into one list and let the consuming node step through it.

Honestly, most people never need this. If you're doing a checkpoint comparison you'll often just re-queue with a different loader - but the moment you have a node that accepts a model list, or a batch-capable workflow that wants several checkpoints at once, this is the junction. It also pairs with the pack's ToModelList if you're wrapping single loaders into list form.

How it works

Same family mechanics, no surprises. inputs_len (default 2, up to 32) sets the number of model-list inputs, and after changing it you right-click → "update Inputs" for the sockets to appear (the README's ❔ marker). Each input is a list of MODEL objects; they're appended in order onto the output.

The MODEL type is a Python object (the loaded checkpoint), not a tensor, so "list of models" works exactly like a list of anything else. Just don't confuse it with the pack's MODEL-list making nodes - Extend takes lists in; ToModelList takes single models and wraps them into a list.

Install

It ships with the bmad4ever pack, so install that once:

cd ComfyUI/custom_nodes
git clone https://github.com/bmad4ever/comfyui_bmad_nodes

then restart ComfyUI. Manager users search "comfyui_bmad_nodes". The pack's Python requirements install alongside and aren't used by this node.

Common issues

• Sockets not appearing after inputs_len changes. Right-click → "update Inputs".
• Feeding a single MODEL. Wrap with ToModelList first.
• Consumer mismatch. This node is only useful if something downstream actually accepts a model list - check your target node's socket for the [ ] before building the chain.

It's a niche connector in a niche family. When you need it, it saves you from an absurd amount of duplicated graph; when you don't, you'll never notice it's installed.