Derp Vae Loader

Every VAE switcher has a ritual: open the VAE Loader, scroll through the dropdown, curse, try the one you actually meant. Derp Vae Loader replaces that with a deck of clickable VAE cards sitting right on the node. Click a card, it becomes the active VAE. That's the whole pitch, and honestly it's enough - if you A/B decodes while dialing in a model, one-click switching is the difference between a workflow you use and a workflow you fight.

It's part of xcp_derp-UI (lordwedggie/xcp_derp-UI-Release), a small UI-framework pack that overlays custom control surfaces on the regular ComfyUI graph. The VAE Loader is one of seven loaders it ships, and it loads .safetensors, .pt, and .ckpt VAEs from your ComfyUI/models/vae folder. There's a refresh button so you don't restart ComfyUI when a file appears, a remove button, drag-to-reorder, and a search tab so you don't scroll past eighty-seven files named vae-ft-mse-840000-ema-pruned variants.

How it "loads" - spoiler: it mostly doesn't

Like every node in this pack, DerpVaeLoaderNode is a "pure virtual" Python shell: no inputs, one VAE output named vae, and a do_nothing() method that returns None. It never touches disk. Instead the frontend broadcasts a wireless signal containing a tiny descriptor - basically {vae_name: "whatever.safetensors"} - and the Derp Router (xcpDerpSignalOut) does the actual loading on the backend, resolving that name against ComfyUI's VAE folder and handing you a real VAE object.

That's why the pack's own docs are blunt about it: "This loader needs derpRouter to function. Without it, it's just a decorative rectangle." Add a Router to your workflow first, every time.

One genuinely nice extra: a system-panel toggle called Extract VAE from model switches the file browser from your vaes folder to your models folder and rips the VAE straight out of checkpoint files. If a model ships with a baked-in VAE you want to compare against, you don't need a separately downloaded file - the Router's fallback machinery extracts it via comfy.sd on the fly. There's also a "Show Folder Names" toggle if you'd rather your deck not display embarrassing directory paths.

The one output

The schema is minimal on purpose:

• No inputs.
• One VAE output, vae - again a type label more than a real socket, since the value travels wirelessly.

The output that actually matters is on the Router. In the pack's own example workflow, the Router's slot carrying this VAE plugs straight into VAEDecode's vae input. So: VAE Loader → Router → VAEDecode, and click between VAEs as much as you want. Which matters more than usual here, because the whole VAE game is "use the one your checkpoint was trained against," not "use the famous one" - the KB's VAE panel hammers this: modern checkpoints bake their VAE in, so attaching a random one is often the mistake. Fast switching is exactly how you find out which is which.

Installing it

Same pack, same boring install. Via ComfyUI Manager, search "xcp_derp-UI" or "Derp"; or:

cd ComfyUI/custom_nodes
git clone https://github.com/lordwedggie/xcp_derp-UI-Release

Restart and you're done. No requirements.txt, no model downloads - it reads whatever's already in your vaes and models folders. That's the cleanest part of this pack: install is genuinely clone-and-restart.

Where people get burned

• No Router = decorative rectangle. If you queue and the decode silently uses something else, or nothing happens at all, you almost certainly forgot the Derp Router. It's not optional for this node; it's the loader.
• "Could not resolve VAE signal for 'name'" at queue time. The name in your deck isn't in your vaes folder (or your models folder, if you're extracting). Click refresh after dropping a file in - the deck doesn't watch the folder.
• Wrong colors / washed decode isn't the loader's fault - it's the "right VAE" problem above. The deck just makes trying the alternatives painless, which is its whole job.

One honest caveat: this is a niche, fast-moving pack with effectively no community footprint yet. The wireless magic is neat, but it's an indy project's opinionated design, and the debug path when a signal doesn't resolve is a runtime error rather than a red wire. If you live on stock VAE Loaders this is a quality-of-life upgrade worth trying; if you'd rather stay on the boring path, you're not missing a capability - you're missing clicks.