Derp Seed V2

The Derp Seed V2 is a seed controller with a brain: it tracks your seed history, gives you modes instead of a bare number box, and even has a "lucky number" because sometimes you want the universe to pick. It's part of xcp_derp-UI (search "xcp_derp-UI" in ComfyUI Manager, by lordwedggie), under derpNodes/ControlDeck.

Why you'd want it

If you've ever been bitten by the classic ComfyUI seed trap - the one the KB's comfyui-node-plumbing.md documents: you find a great image on a random seed, flip the KSampler's control_after_generate to fixed, and the good seed was already overwritten after the run that produced it - you'll immediately see the appeal of a dedicated seed node. Seed V2 is built for seed-hunting: you can see which seed made which image, re-randomize with a click, step incrementally, or lock a favorite, all in one place.

How it works

The Python side is small: it takes value (INT, 0 to 2^64-ish) and values_data (STRING, default "{}", holding the UI state), and returns the seed as an INT output. Crucially, it implements IS_CHANGED returning NaN, which - per the same KB doc - is the engine trick that forces a node to run every single queue, so your seed actually updates instead of getting cached into a stale value.

The real behavior is in the UI. Click the big seed display to randomize, or switch to edit mode and type a specific number. The mode control cycles through Random, Increment, Fixed, and Decrement - random gives a new seed per queue, increment counts up (great for systematic exploration), fixed stays put, decrement does what you think. There's an execute button that queues a prompt and a stop button that halts the current run, both of which only light up when they're usable. Under the system panel you control History Logs (how many previous seeds to keep - handy for "wait, which one was the good one?"), Decimals (digit count, default 15 because ComfyUI seeds are massive), and the Lucky Num display.

Like the other derp ControlDeck nodes, it broadcasts its seed as a wireless signal - if you're using derp loaders downstream you'll need a derpRouter to route it.

The author's own warning

Read this before you judge the layout: Seed V2 is built on the Uncle framework, not the newer Fatha one, and the author is upfront that it "has layout quirks that cannot be fixed without a full rewrite. It runs fine, but it'll occasionally do something weird with spacing or alignment and you'll just have to live with it." A Fatha-based replacement is planned. So if this node occasionally looks slightly off, that's a documented quirk, not you.

Install

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

Restart ComfyUI. No pip requirements, no model downloads, no npm step. Manager users: search xcp_derp-UI.

Honest takes

This is the original derp seed, and V3 is the rewrite on the newer framework. If you're starting fresh, V3 is the better long-term bet; V2 exists for people whose workflows were built on it. But if you already use V2 and it works for you, the quirks are cosmetic. And as always with this young pack: no third-party docs exist yet - the bundled derp_docs/ControlDeck Nodes/Derp SeedV2.md is the reference, and it includes that layout-quirk warning verbatim.