ChebyFlow for ComfyUI

ChebyFlow is an adaptive two-stage Chebyshev flow sampler for ComfyUI, developed and tuned around MiniMax H3 / CONST rectified-flow sampling.

The core idea is to use the second model evaluation not at a fixed midpoint, but at an adaptive internal stage whose position is driven by the locally observed flow behavior. The sampler also adapts correction strength and can do so per latent channel.

Nodes

ChebyFlow Auto Sampler

Recommended default. It self-calibrates online during the current generation using the two model evaluations it already performs per interval. No prior runs, logs, or extra NFEs are required.

Controls:

coordinate
base_stage_position
min_stage_position
max_stage_position
adaptivity
quality_bias
turbo_mode
correction_granularity

Presets:

balanced
detail
smooth
stable
dynamic

turbo_mode is an orthogonal low-step operating mode intended for distilled / Turbo-LoRA workflows around roughly 6–10 steps. It shortens warm-up, accelerates the online observer, biases the internal stage later, and narrows the final correction range for stability on large intervals.

Recommended normal default:

coordinate              = flow_lambda
base_stage_position     = 0.72
min_stage_position      = 0.58
max_stage_position      = 0.96
adaptivity              = 1.00
quality_bias            = balanced
turbo_mode              = false
correction_granularity  = per_channel

Recommended low-step / Turbo default:

coordinate              = flow_lambda
base_stage_position     = 0.72
min_stage_position      = 0.58
max_stage_position      = 0.96
adaptivity              = 1.00
quality_bias            = balanced
turbo_mode              = true
correction_granularity  = per_channel

ChebyFlow Advanced Sampler

Manually tunable version. Defaults keep the strongest combined configuration found during development:

coordinate                  = flow_lambda
base_stage_position         = 0.70
min_stage_position          = 0.55
max_stage_position          = 0.95
adapt_strength              = 1.00
curvature_smoothing         = 0.50
stage_curvature_scale       = 0.12

curvature_metric            = combined
residual_weight             = 1.00
angle_weight                = 1.00
magnitude_weight            = 0.50

correction_mode             = curvature_down
correction_granularity      = per_channel
correction_min              = 0.88
correction_max              = 1.08
correction_curvature_scale  = 0.12

How ChebyFlow works

For each non-terminal outer interval, ChebyFlow:

evaluates the model at the current state;
predicts an internal Chebyshev stage;
evaluates the model again at that stage;
measures local flow behavior using residual change, angular turning, and magnitude change;
adapts the next internal-stage position;
adapts the current correction strength, optionally per latent channel;
applies the two-stage corrected update.

The Auto sampler additionally maintains fast and slow online statistics so it responds to relative difficulty within the current generation, rather than requiring hand-tuned absolute curvature scales.

Approximate cost: ~2 model evaluations per non-terminal interval.

Installation

Copy the folder to:

ComfyUI/custom_nodes/ComfyUI-ChebyFlow/

Then restart ComfyUI completely.

Both nodes output SAMPLER and connect directly to the sampler input of SamplerCustomAdvanced.

Compatibility

ChebyFlow currently validates that the active ComfyUI model sampling object is CONST / rectified-flow. It was developed specifically around MiniMax H3 and should be considered experimental outside that setting.

Backward compatibility

The internal ComfyUI node class IDs remain compatible with the previous H3 Adaptive Chebyshev development builds, while the user-visible node names are now ChebyFlow Auto Sampler and ChebyFlow Advanced Sampler.