Sonder Guides Bridge Start

Sonder Guides Bridge Start is the first half of the loop that makes timeline guide frames work in Sonder Editor. In a Sonder project, guide frames are reference images you drop onto the timeline wherever you want them - first frame, last frame, or anywhere between - and the model fills what falls between. That's the whole "first/last/any frame" workflow, and this node is how those frames get into your generation graph one at a time.

The problem it solves is the classic ComfyUI shape problem: the number of guides in your selected range varies from run to run. You can't wire a fixed LTXVAddGuide chain and hope it lines up. So the Start node opens a loop that emits one (image, frame_index, strength) tuple per iteration, with the loop body being your guide-processing nodes - LTXV Preprocess, LTXVAddGuide, or whatever your model needs - wrapped between Start and its paired End node. No LTXVAddGuideMulti, no hand-indexing. If the section has no guides, the loop just doesn't run.

How it works

Wire the project output from a Sonder Editor in. iteration_index is the loop counter (0-based) and bridge_overrides_json is workflow-local override state - {} unless you're forcing something. The outputs are:

• flow_control - the loop handle that connects Start to End.
• image - the guide image for this iteration.
• frame_index - where on the timeline it sits (rebased to the render window).
• strength - the guide's conditioning strength.
• value_0 … value_7 - dynamic passthrough sockets that carry loop-carried state around the body, so a value from before the loop survives to after it.

A note from the README worth remembering: Sonder has two guide injection paths - this bridge, and the editor's CSV outputs - and you should not inject the same project guides through both. Pick the bridge for generation, or the editor export, not both.

Install and the wiring you'll actually do

Ships with the pack: ComfyUI Manager search Sonder Editor, or git clone https://github.com/SonderSaid/ComfyUI-Sonder-Editor.git + pip install -r requirements.txt + restart.

The one beginner trap: the Bridge Start looks like a standalone node but is half of a loop - forgetting the End node leaves the graph hanging, and on older ComfyUI builds the "Node Expansion" loop machinery can look like a missing node until you wire the pair. The launch-thread advice from the author is the template: drop the Bridge Start, put your usual guide nodes (LTXV Preprocess, LTXVAddGuide, whatever your model uses) between it and Bridge End, wire it once, and every guide in the section flows through automatically.