IAMCCS V2V Active Backend Switch

Video-to-video work in the IAMCCS system can route through several different engines - LTX, SCAIL, WanAnimate, pose transfer - and each one is a different sub-graph with different inputs. V2V Active Backend Switch is the node that decides which of those engines is live this run, so you can keep every backend wired into one graph and switch by changing a setting instead of re-plumbing.

The word "Active" matters. Instead of a manual dropdown, it reads the control bus metadata (the backend_mode / backend_family / backend_profile values) carried on the cine_linx, and routes to whichever backend input matches. It's a lazy node - only the selected branch actually evaluates, so the unselected backends aren't doing work or consuming VRAM. If you've ever used a ComfyUI AnySwitch or lazy-routing utility, this is that idea specialized for the V2V system.

Inputs

• cine_linx - required; the metadata that decides the selection.
• control_bus (optional) - a IAMCCS_V2V_CONTROL_BUS whose backend settings override the linx's. If a planner wrote a backend mode into the control bus, that wins.
• ltx, scail, scail_multi, wananimate, pose_transfer (optional) - the candidate backends' outputs. Any type (*), lazy-evaluated, so only the selected one gets computed.

Outputs

• selected - the output of whichever backend was chosen, passed through untouched.
• report - which backend key matched, so you can see what got routed.

Install

Ships in IAMCCS-nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/IAMCCS/IAMCCS-nodes.git

or via ComfyUI Manager (search "IAMCCS"), restart.

The selection logic

The matching is string-based on the combined mode/family/profile. If it sees pose or flux_klein it routes to pose_transfer; wan → wananimate; scail_multi/multi_person_identity → scail_multi; scail → scail; otherwise it lands on ltx. Practically: whatever sets backend_mode on the control bus (the Shotboard planner V2V does) determines which branch fires. If nothing sets it, the default ltx_simple backend wins - which is the safe fallback.

The trap is wiring quality: because the inputs are all *, ComfyUI won't complain if you connect mismatched outputs, and a typo in a bus string silently routes to the default backend. Check the report output the first time you switch; it'll tell you exactly which branch matched. If you're not using the IAMCCS V2V bus/Shotboard system at all, this node is overkill - it exists to be driven by the bus, not by hand.