MiniMax H3 External BlockSwap Bridge / 流式驻留桥接 (Advanced)

This one is niche, so let's be clear about what it is and isn't up front. It's a bridge - it builds a BlockSwap configuration payload for the optional external streaming MiniMaxH3KSampler from xiaolibai-sys/ComfyUI-MiniMaxH3. It does not patch or replace ComfyUI's official MODEL path, it doesn't run the sampler itself, and it does absolutely nothing unless you've separately installed that external pack and are using its streaming runtime. If you're on the stock ComfyUI H3 sampler, this node is not for you - skip it and don't feel bad.

BlockSwap is the memory trick where model blocks get swapped between VRAM and disk (or pinned host memory) instead of being held resident, which is how some streaming pipelines fit big models on small cards. This node's job is to translate the settings into a payload the external runtime understands, in the exact MINIMAX_H3_SWAP type it expects, with a report of what it built.

The inputs that matter:

• profile - upstream_default_auto strictly reproduces the upstream runtime's current defaults (it only reads the fields below when you pick manual).
• block_to_swap (default 47) - which block starts the swap region; the H3 stack here is treated as 0–50, so 47 is "near the end".
• hot_blocks, prefetch, prefetch_count, pin_memory, disk_workers - the resident/streaming knobs. Defaults are conservative (2 prefetch, 2 disk workers, pinned memory on).
• auto_vram - lets the upstream runtime shrink the resident window based on the current sequence and available VRAM. Keep it on.
• offload_dit and dtype (bfloat16) - further residency controls.
• require_external_runtime (default true) - fails early with a clear error if the external streaming loader isn't installed, which beats discovering it three nodes later.

Outputs: block_swap_args (the MINIMAX_H3_SWAP payload for the external sampler) and report_json.

Two honest warnings from the pack. First, the external dependency: this needs xiaolibai-sys/ComfyUI-MiniMaxH3 installed separately - the T8 pack never ships it, and the README frames this whole path as "16GB not stress-verified." Second, the payload only serves the external MINIMAX_H3_* types; it won't interact with the official MODEL path, so wiring it into a stock graph won't do anything useful.

If you're not already in the streaming-BlockSwap world, this node reads like a spec sheet for a foreign runtime. That's because it is one. But if you are using the external streaming sampler and want the T8 pack's defaults + a visible JSON report of what got passed over, this is the clean way to do it.

Install is the same pack route - ComfyUI Manager, search "MiniMax H3 Audio T8", or:

cd ComfyUI/custom_nodes
git clone https://github.com/T8mars/comfyui-minimax-h3-audio-T8

Restart after. No forced pip deps; H3 weights are yours to provide. And remember the external streaming pack is a separate install - check that before you start chasing "why is my block_swap_args never consumed" errors.