MiniMax H3 · Lazy Delivery Path Router

The R42 universal graph can have four delivery pipelines hanging off the same native checkpoint - native/windowed, RTX final, fast two-pass, and LTX master. So how does ComfyUI know which one actually ran? IAMCCS_MiniMaxH3UniversalPathRouterR42 is the answer: a lazy router that makes the universal graph an output node and resolves to exactly one of those routes' results.

Here's the elegance. Each delivery branch outputs a video_path string. This router takes all four as optional, lazy inputs and asks ComfyUI for only the one that matches the shot plan's selected route. Read its check_lazy_status and you'll see the mapping: off/h3_pixel_refine routes request native_or_windowed_path, the RTX route requests rtx_final_path, the fast route requests fast_path, and anything master-related requests master_path. The other three delivery branches are never evaluated, which is the entire point of the architecture - you can leave every branch wired up and only the chosen one burns GPU time.

Because it's an output node, it's also where the run "ends" for UI purposes. It reports the resolved route, the current segment out of total, and whether the path is ready. And IS_CHANGED returns NaN, so it always re-executes rather than trusting cache - for a router whose job is to reflect the current state of the run, that's the right call.

Inputs and outputs

Required: cine_linx (the shot plan that decides the route), current_segment and total_segments. Optional: the four lazy STRING path sockets - native_or_windowed_path, rtx_final_path, fast_path, master_path - each fed from the matching delivery node's video_path output.

Outputs: video_path (the actual file path of whatever route ran), delivery_ready (BOOLEAN - true once a real path is in hand), and report.

The honest take

If you're following an R42 reference workflow, this is the node you can point at as "where the render's result comes out." You don't set a dropdown on it - the route comes from the plan, set elsewhere (RouteControlR42 reads the same plan). The router is downstream of that decision and just reports it. Two things will bite you if you hand-wire it:

• The route in the plan must match a connected branch. If the plan says RTX but you didn't feed rtx_final_path, the router asks for an input that never comes and you get no path - the report will show "waiting" and delivery_ready will be false.
• The master path only becomes ready after the whole native film is checkpointed and merged, so don't read "not ready yet" as a bug mid-run. It's the master-delivery design doing its two-phase thing; the report tells you which route and segment it's waiting on.

Install

Part of IAMCCS-nodes:

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

or via ComfyUI Manager (search "IAMCCS"), then restart. It needs the full R42 ecosystem plus the H3 stack - current ComfyUI (≥ 3.x), MiniMax H3 (~42 GB) and VAEs - and an LTX setup if the master path is in play. Lazy inputs are a modern ComfyUI feature, so keep ComfyUI updated. H3's licence, as always, excludes the US, EU, UK and Korea.