Modify LTX Model

This one sits in the ltxtricks cluster with the FlowEdit and attention-injection nodes, and it's the plainest of the lot: model in, model out, no knobs. It patches your LTX model so the editing-trick nodes downstream can hook into it. If you're building an LTX video-editing graph - inversion, attention injection, the whole remix pipeline - this is usually a required prep step that wires the model up to accept those interventions.

The reason it exists as a separate node instead of being baked into the sampler is the same reason ComfyUI splits anything: composition. The attention-injection and FlowEdit machinery needs the model instrumented in a particular way before it can read and write attention or run a reversed pass. Rather than every trick node re-patching the model itself, one node does the modification once and passes a prepared model down the graph. It's the "prime the engine" step.

How it works

You feed it a MODEL and it returns a MODEL - a version prepared for the ltxtricks editing nodes. That's the entire contract. There are no exposed parameters, which is honest: whatever it toggles is internal setup, not something you're meant to tune. You place it early, right after you load the LTX model, and route its output into the rest of the editing chain.

The inputs and outputs that matter

Nothing to configure. Literally:

• model (MODEL) in.
• MODEL out - wire it into your FlowEdit sampler / attention-injection branch.

No strength, no mode, no seed. If you're looking for a dial here, there isn't one - the tuning lives in the sampler and injection nodes further along.

How to install it

ComfyUI Manager: Ctrl+M, Install Custom Nodes, search LTXVideo, install, restart. Manual clone:

cd ComfyUI/custom_nodes
git clone https://github.com/Lightricks/ComfyUI-LTXVideo

then restart. Part of Lightricks' official LTXVideo pack. The node itself is a lightweight patch and downloads nothing; the LTX model it modifies is where the weight and VRAM go (the pack targets the LTX-2 family, so expect the full checkpoint, the Gemma 3 text encoder, and a card with real headroom).

Common issues & troubleshooting

You added it but nothing downstream works. This node prepares the model; it doesn't do anything visible on its own. If the FlowEdit sampler or attention-injection nodes still misbehave, the problem is almost always further down the chain (inject steps at 0, q/k/v flags off, an empty attention bank), not here.

You're not sure whether you need it. If you're doing plain LTX generation - text-to-video, image-to-video, no source-clip editing - you almost certainly don't. ModifyLTXModel earns its place only in the editing/tricks pipeline. Dropping it into a normal generation graph adds a patch you don't use.

It's not in the menu where you expected. Look under the ltxtricks category, and search the node menu by its display name "Modify LTX Model." Like the rest of this cluster, it's an advanced editing tool rather than a headline generation node, so it's easy to miss if you're browsing the Lightricks generation categories. The cleanest way to get the wiring right is to open one of the pack's FlowEdit example workflows and see where this node lands in the chain.