Adds a `flux2_klein` model family for Black Forest Labs' Flux.2 Klein 9B
release. Different architecture from Flux.1 D — required a separate
workflow rather than extending flux_unet.
Architecture differences from Flux.1 D:
- Single Qwen3-8B text encoder via CLIPLoader(type=flux2), producing
12288-dim conditioning (3 stacked hidden layers). NOT DualCLIPLoader.
- EmptyFlux2LatentImage instead of EmptySD3LatentImage (different
latent shape).
- Custom-sampling pipeline: Flux2Scheduler -> SIGMAS, fed into
SamplerCustomAdvanced together with BasicGuider + RandomNoise +
KSamplerSelect. No standalone KSampler node, so the caller's
scheduler argument is ignored.
- Dedicated VAE: flux2-vae.safetensors (not Flux.1's ae.safetensors).
Detection:
- New FLUX2_KLEIN_PATTERNS constant lists known Klein filenames
("lust_", "moodydesire"). _is_flux2_klein() checks base_model field
first ("flux.2 klein" / "flux2 klein") then filename pattern.
- detect_model_family() runs the Klein check BEFORE flux_unet, so
Klein checkpoints that also match UNet-only patterns (lust_v10,
moodyDesireMix) correctly route to flux2_klein.
Affected checkpoints reclassified from flux_unet -> flux2_klein:
- lust_v10.safetensors (Flux.2 Klein 9B-base per CivitAI DB)
- moodyDesireMix_v20PRO.safetensors (Flux.2 Klein 9B)
Still flux_unet (genuinely Flux.1 D UNet-only):
- cyberrealisticFlux_v25, fcFluxPonyPerfectBase,
getphatFLUXReality_v11Softcore.
Required ComfyUI host setup (one-time):
- /home/madcat/comfyui/models/text_encoders/qwen_3_8b_fp8mixed.safetensors
(8.1 GB, from Comfy-Org/vae-text-encorder-for-flux-klein-9b on HF)
- /home/madcat/comfyui/models/vae/flux2-vae.safetensors (321 MB)
Verified end-to-end on madcat: lust_v10 generated successfully through
the new flux2_klein workflow (~85s per image at 1024x1024, 20 steps).
7 new tests; 253 -> 259 total. Existing flux_unet tests retargeted to
genuine Flux.1 D checkpoints (getphat, fcFluxPony, cyberrealisticFlux).
aladac
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