basicIn_Seed

The third of this pack's "pull a stock KSampler widget out into its own node" trio, alongside basicIn_Sampler and basicIn_Scheduler. Same motivation: if you've got a base pass and a refiner pass and you want them locked to the same seed instead of manually typing the same 19-digit number into two separate widgets, this node gives you one place to set it and one wire to fan out.

What it is

One field, seed - a genuinely huge integer range, defaulting to 0 and capping out around 1.8 * 10^19 (the full 64-bit unsigned range ComfyUI's own seed widgets use). One output, seed, matching. Wire it to every sampler in your graph that needs to reproduce the same noise.

Why locking a seed actually matters

This isn't just a convenience node - a consistent, fixed seed is the entire foundation of how debugging a diffusion workflow works. The universal community advice for diagnosing why a generation looks wrong is: lock the seed, change exactly one other variable, compare. Randomize the seed while you're also changing prompts or settings and you genuinely can't tell what caused the difference you're looking at. If you're troubleshooting an Apt_Preset workflow and something looks off after a change, the first thing to check is whether this node (or whatever seed source you're using) actually stayed fixed across your test runs.

Where it fits in a multi-stage graph

The real payoff shows up once you've got more than one sampler in the same workflow - an basic_Ksampler_adv first stage handing off to a second basic_Ksampler_adv for refinement, say. Both stages need the same noise_seed for the handoff to make sense, and typing the same long number into two widgets is exactly the kind of thing that silently drifts apart after a few edits - you change one, forget the other, and spend ten minutes wondering why your "identical" comparison run looks different. Wire this node's output to both and that class of bug simply can't happen.

Installing it

Search "ComfyUI-Apt_Preset" in ComfyUI Manager, or:

cd ComfyUI/custom_nodes
git clone https://github.com/cardenluo/ComfyUI-Apt_Preset.git

Run install.bat on Windows (pip install -r requirements.txt on Linux/Mac), restart ComfyUI. No models - it's a plain integer primitive with a very large ceiling.

Common issues

The gotcha specific to this node: unlike a stock KSampler's seed widget, which typically comes with a "randomize after each run" control built into the ComfyUI UI, this is a bare value node - it stays exactly where you set it unless you change it yourself, which is usually what you want but can surprise you if you're used to the control-widget behavior auto-incrementing for you between queues. If you're getting the exact same output run after run and expected variation, check whether you're still pointed at this fixed-seed node rather than a randomizing source. The upside of that same behavior: once you've found a seed you like, it stays locked across every downstream sampler you've wired it to, with no risk of one sampler drifting to a different seed than the others.