ModelMergeAuraflow_motorway_edition

AuraFlow was the first serious open-weights flow-matching DiT - the architecture family that Flux later made famous - and its block layout is completely unlike a U-Net. There's no encoder/decoder split; there are stacked transformer blocks, a dual-stream "double" section up front and a single-stream tail, plus embedders. ModelMergeAuraflow is ComfyUI's per-block merge for exactly that layout, and this is its Motorway-ed clone.

How the blocks map

The node exposes a ratio per named region, all defaulting to 1.0:

• init_x_linear, positional_encoding, cond_seq_linear, register_tokens, t_embedder - the input embedders and conditioning wiring.
• double_layers.0–double_layers.3 - the early dual-stream blocks, where text and image tokens attend to each other separately before merging.
• single_layers.0–single_layers.31 - the long single-stream tail, the bulk of the model and where most of the texture lives.
• modF and final_linear - the output projection.

The same merge-node gotcha applies and is worth stating again: all ratios default to 1.0, so an untouched node returns model2. Set a base blend first, then push individual regions. With DiT merges, the interesting split is usually double layers (conditioning/structure) versus single layers (finish).

One thing to know before you invest time here: AuraFlow's checkpoint ecosystem was a flash in the pan - the model was important as a proof that open flow-matching worked, but most people moved to Flux-class models for merging. This node is here because ComfyUI supports the architecture, not because it's the merge everyone's doing. If you're actually working with AuraFlow checkpoints, it's your tool; otherwise you're learning the layout for its own sake.

The inputs

• INPUT_model1_key (default model1) and INPUT_model2_key (default model2) - the two AuraFlow models.
• The block ratios above, each 0.0–1.0, step 0.01, default 1.0.
• OUTPUT_MODEL_key (default MODEL) - where the merged model lands.

The wrapper keeps every ratio as a widget, turns the two models into key strings, and keyed-writes the result. Runtime behavior matches stock ModelMergeAuraflow.

Install

One install for the whole pack. ComfyUI Manager, search "ComfyUI_agilly1989_motorway", or:

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

Restart ComfyUI. No requirements.txt, no model downloads.

Troubleshooting

• Result is pure model2? Every ratio defaults to 1.0 - set a base blend first.
• Only merge AuraFlow with AuraFlow (and matching sizes). The double/single layer counts differ across model families; Flux has 19 double + 38 single, so the numbers won't line up.
• 'MotorwayClass' object has no attribute 'hash_' = a model key isn't in the Motorway; check the loaders ran and the key spelling matches (case-sensitive).
• Pack caveats: BETA, and the newest published version (1.1.7) disabled clone generation, so on a fresh install these _motorway_edition nodes may be missing from the menu. They're present in the 1.1.0–1.1.6 builds comfy.icu indexed.