SenseNova U1.5 AEGIS Loader

The name makes it sound like some GPU-residency magic, but the first thing to know about the SenseNova U1.5 AEGIS Loader is simpler and weirder: this node will never fetch model weights for you. Drop a checkpoint in, pick it from the list, and it loads whatever is already sitting in ComfyUI/models/diffusion_models/. If nothing's there, you get an error, not a download. That's deliberate - model licensing is a tangle and the author chose to stay cleanly out of it.

So why "AEGIS"? That's the VRAM management scheme underneath, and it's the actual reason you'd use this pack instead of wrestling SenseNova U1.5 into ComfyUI yourself. SenseNova U1.5 is an 8B multimodal model (text and image go through one token stream - it's why the pack ships both a text-to-image and an image-edit node). People have been running it in ComfyUI for a while, but the usual path involves a big repo checkout and model files scattered in several places - a commenter on r/comfyui called those setups "convoluted." This loader collapses all of it into a single INT8-quantized safetensors file that loads directly into a meta model, streaming tensor-by-tensor with safetensors.safe_open so you never hold a second full-precision copy in RAM.

The inputs that matter:

• checkpoint - picks from ComfyUI/models/diffusion_models/. Use the pack's recommended SenseNova-U1.5-8B-MoT-pruned-int8_convrot.safetensors (the author targets the final MoT checkpoint, not the older Preview one). You can grab it from the joyfox/SenseNova-U1.5-8B-MoT-FP8 Hugging Face repo, which also has BF16 and scaled FP8 variants if you'd rather not quantize.
• vram_mode - the AEGIS heart. aegis (default) keeps generation weights resident and prefetches layers asynchronously; its default profile targets 16 GB cards. balanced and low offload more for tighter cards; full shoves everything to GPU and can OOM on consumer hardware. Start at aegis, drop down only if you see pressure.
• dtype - bfloat16 default, float16 if you're tight on VRAM.
• attention - auto tries FlashAttention and falls back to PyTorch SDPA when it's missing or broken. That fallback is the correct default; don't touch it.

Outputs are a model socket (SENSENOVA_U15_AEGIS_MODEL) that feeds the pack's other nodes, plus an info string with a JSON dump of what got loaded - checkpoint path, quantization format, dtype, VRAM mode. Handy for confirming you actually got the INT8 ConvRot file and not some doppelganger.

Installing it

Easiest: ComfyUI Manager → install custom nodes → search "SenseNova" and install the pack, then restart ComfyUI. Or by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/vizart-vj/ComfyUI-SenseNova-U1.5-AEGIS

Then restart and put the checkpoint in ComfyUI/models/diffusion_models/ (the LoRA goes in ComfyUI/models/loras/ if you use one). On first startup the pack bootstraps its runtime: it downloads the SenseNova-U1 runtime archive and tokenizer config from GitHub, and installs small aux packages like accelerate, sentencepiece, and safetensors. Notice it explicitly leaves ComfyUI's own torch and transformers alone - that's rare and good, most similar packs try to own your whole Python env. So: internet needed once for the runtime, but never for weights.

Where people get burned

• "Why is my node listing empty?" The checkpoint combo reads diffusion_models at startup. Put the file there, restart ComfyUI, then check. Nothing auto-downloads, remember.
• "First load looks stuck." It's downloading the runtime and tokenizer files. Give it a minute; it's one-time.
• "It OOMs." You're probably on full or a sub-16 GB card. Try low, and consider float16 dtype.
• "It says attention broken." Leave it on auto - SDPA is a perfectly good fallback, you don't need FlashAttention for this to work.