CLIPMergeAdd_motorway_edition

Model merging gets all the attention, but you can merge text encoders too. CLIPMergeAdd is the core ComfyUI node that takes two CLIPs and adds the weights of the second onto the first - the additive extreme of CLIP merging. This _motorway_edition is the version wired for agilly1989's Motorway pipe, so both CLIPs come out of the Motorway by key, and the merged result goes back in under a key you name.

Honest framing: CLIP merging is a niche within a niche. Most people run one text encoder and never think about blending two. The use cases that keep this alive are experiments like combining the prompt-following of one CLIP with the style bias of another, or reproducing a known-good merged-CLIP recipe from a workflow someone shared. If you're not deliberately doing that, you don't need this node - but if a Motorway workflow you inherited uses it, now you know what it's doing.

How it works

The wrapper pulls two things out of the Motorway and writes one back:

• INPUT_clip1_key - key for the base CLIP (default clip1)
• INPUT_clip2_key - key for the CLIP to add on (default clip2)
• OUTPUT_CLIP_key - where the merged CLIP goes (default CLIP)

Under the hood it instantiates the real core CLIPMergeAdd, feeds it the two CLIPs pulled from those keys, and stores the result under the output key. The only visible output is the MOTORWAY 🚌💨.

"Add" here means the second CLIP's weights get summed onto the first - there's no ratio slider to soften it. If you want a blend you can dial in, that's the separate CLIPMergeSimple node (ratio-based) or CLIPMergeSubtract (subtract clip2 scaled by a multiplier). Add is the blunt instrument; the other two are where the fine control lives. A common pattern is to use Add to fold a small, specific tweak onto a base CLIP, then let the downstream text-encode nodes read the merged result from the CLIP key.

Motorway specifics

MOTORWAY 🚌💨 is required here (the original has connection inputs, so the generator made it so). The defaults assume your chain stored the two source CLIPs under clip1 and clip2; if your loaders wrote them under CLIP instead, update the key fields - a key that was never written throws the signature 'MotorwayClass' object has no attribute 'hash_' error. Keys overwrite as they flow down the chain, so don't write the merged result over a source CLIP you still need downstream.

Install

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

Restart, or find "ComfyUI_agilly1989_motorway" in ComfyUI Manager. No pip dependencies, no model downloads.

Fine print

The pack is an explicitly-beta side project - README opens "BIG BROKEN WITH ASYNC WILL FIX WHEN I GET THE TIME/MOTIVATION" - and the current hotfix release has the _motorway_edition clone generation commented out of __init__.py, so on the newest main these nodes may not load at all. Old workflows referencing them and coming up with missing nodes are hitting exactly that. GitHub issues are the channel; the author has stated his Discord DMs get ignored.