LatentBatchSeedBehavior_motorway_edition

LatentBatchSeedBehavior_motorway_edition wraps core's LatentBatchSeedBehavior, a small node that sets one property on a latent: whether the batch should treat its seed as fixed or random. The motorway edition reads the latent from a pipe key and writes the adjusted latent back to a key. There's one widget and two keys - this is the whole node.

What the switch actually changes

When you sample a batch of latents - say, four images generated together - the seed decides the noise. With fixed, every item in the batch shares the same seed behavior, so the images stay consistent with each other in a controlled way (useful when you want the batch to be a family of variations on one base). With random, each slot effectively gets its own randomness, which is what you want when the batch is meant to be four unrelated attempts. The naming is a little abstract, but the practical read is: fixed = batch moves together, random = batch scatters.

It sits in the pack's latent/advanced category, and honestly it's one of those nodes you only touch when a batch is coming out more uniform than you wanted (or less). Most people never need to adjust seed behavior explicitly - the default behavior of the sampler handles it - so treat this as a debugging knob for batch workflows, not a daily driver.

You set:

• seed_behavior - "fixed" or "random" (default "fixed").
• INPUT_samples_key (default "samples") - the latent batch in the pipe.
• OUTPUT_LATENT_key (default "LATENT") - where the adjusted latent lands.

Only output socket is MOTORWAY 🚌💨; read the latent back out via a Motorway AxB ramp when you want to sample it.

Motorway notes

One key in, one key out. The signature error - 'MotorwayClass' object has no attribute 'hash_' - means INPUT_samples_key didn't match anything a node actually wrote into the pipe; check the spelling and that the upstream node ran. Keys are exact and case-sensitive.

Install and the standing caveats

cd ComfyUI/custom_nodes
git clone https://github.com/agilly1989/ComfyUI_agilly1989_motorway

Restart ComfyUI, or install via ComfyUI Manager. No pip deps, no model files - this node only stamps a flag onto the latent's metadata.

Pack-wide reality check: one-developer beta, README-frank about breakage ("IF THINGS BREAK ITS BECAUSE I BROKE IT"), and the current repo HEAD comments out the _motorway_edition registration mid-refactor, so a fresh clone may not even load this node. And the honest recommendation for a node this thin: if seed behavior is the only motorway-ed thing you need, the stock LatentBatchSeedBehavior does the identical job with a socket. The wrapper only earns its keep inside a workflow that's already routing latents through the pipe.