RUM FLUX.2 Diffusers CFG Guider

RUMFlux2DiffusersCFGuider is the node that makes your prompt actually steer RUM. It wraps the loaded RUM model into a CFG guider - positive conditioning, negative conditioning, a cfg value - and produces the GUIDER that SamplerCustomAdvanced samples against. And here's the part that surprises people coming from distilled Klein: this is a real-CFG path, so the negative prompt genuinely works, and CFG is not stuck at 1.

By 2026 the guidance-distilled Klein weights are the ones everyone talks about - CFG 1, negatives dead, raise CFG and you burn the image. RUM is a different animal. It's RimoChan's cross-architecture distillation of Klein, but the reference pipeline uses honest classifier-free guidance, and the pack's shipped workflows default to cfg 9 at 20 steps (the upstream RUM inference defaults). So the r/comfyui instinct of "CFG high = artifact city, CFG 1 = correct" needs a reset here. Negative prompts are not decoration on this node - they're doing work.

Inputs

• model - the RUM model, straight from RUMFlux2LoadNativeModel → RUMFlux2DiffusersMatchModelPatch.
• positive / negative - CONDITIONING from RUMFlux2NativeMatchTextEncode (or hand-built via combine nodes). The negative gets the same Qwen 200 + SDXL teacher 77 treatment as the positive.
• cfg - default 5, shipped workflows use 9. This is your adherence dial; since guidance isn't baked into the weights, going higher is a legitimate lever, not a self-destruct button.
• reference_latents (optional) - the edit path. Feed it the output of RUMFlux2NativeMatchReferenceEncode and the guider injects reference tokens into the conditioning. It only works with RUMFlux2DiffusersEulerSampler - wire it to a stock sampler and the node raises a clear error telling you exactly that.

Output: a single guider → SamplerCustomAdvanced.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/Rinne414/ComfyUI-RUM
cd ComfyUI-RUM
pip install -r requirements.txt
python scripts/download_models.py --comfy-root /path/to/ComfyUI --include-teacher-clip

Restart. Needs recent ComfyUI (v0.26.2+) - the guider builds on ComfyUI's CFGGuider with nested-latent support.

Where people get burned

• CFG muscle memory. Someone ported the "CFG 1" reflex from distilled Klein, then wonders why RUM looks unguided. RUM's CFG 9 default is real. Start there, dial to taste.
• Reference latents on a stock sampler. The edit workflow won't apply, and the error message will name the exact sampler to use instead.
• Mixing match and native nodes. This guider is built for the diffusers-match chain; hand-wiring it into a plain native workflow is how you get conditioning that's neither fish nor fowl.