ComfyUI-Sigmax is a planned model-aware sigma schedule and sampler toolkit for ComfyUI. Its first validation targets are Krea 2 Turbo and Krea 2 RAW; the longer-term design supports versioned profiles for other flow-matching and diffusion model families.

Status: pre-alpha foundation. No user-facing ComfyUI nodes are implemented yet. The current repository provides a side-effect-free package shell, packaging metadata, quality gates, and the first framework-independent ownership/domain contracts. It does not yet construct numerical schedules.

Why Sigmax

Sampling systems often mix four different concerns:

how a model interprets time or sigma;
how the sigma sequence is constructed;
which numerical sampler integrates model predictions;
which settings are authoritative for a specific model variant.

Sigmax will keep those concerns separate. A schedule must come from an explicit, traceable profile; experimental transforms must remain distinguishable from reference behavior; and features that require stateful sampler steps must not be represented as inert sigma controls.

Planned Product Shape

The intended toolkit includes:

official-parity Krea 2 Turbo and resolution-aware Krea 2 RAW schedules;
a pure, independently testable schedule engine;
versioned model profiles with evidence and provenance;
simple model-aware and advanced schedule nodes;
schedule inspection, comparison, metadata, and fingerprints;
native ComfyUI Euler reuse where it is mathematically equivalent;
separate full-sampler implementations only where sigma tensors are insufficient;
numerical golden, parity, property, and integration test lanes.

These are roadmap targets, not claims about the current package.

Current Repository Surface

The import contract is intentionally minimal:

import comfyui_sigmax

assert comfyui_sigmax.NODE_CLASS_MAPPINGS == {}
assert comfyui_sigmax.NODE_DISPLAY_NAME_MAPPINGS == {}

Empty mappings prevent unfinished nodes from being registered. Runtime dependencies are also empty; Diffusers is an optional reference dependency used for later parity research.

The pure core currently exposes explicit schedule ownership, sigma domains, transform stages, pre-execution compatibility validation, and immutable request/result structures:

from comfyui_sigmax.core import ScheduleInputs, ScheduleOwnership, SigmaDomain

ownership = ScheduleOwnership.EXTERNAL_SIGMAS
domain = SigmaDomain.UNIT_FLOW
requested_inputs = ScheduleInputs(steps=8, width=1024, height=1024)

Model-native, externally constructed, and model-patched schedules are mutually exclusive. External transforms cannot be silently applied to native or patched ownership. Requested and effective inputs are stored separately, and effective step or dimension changes require an explicit override record.

Development Setup

Python 3.10 or newer is required.

Windows:

python -m venv .venv
.\.venv\Scripts\python.exe -m pip install -e ".[dev]"
powershell -File scripts/run_full_tests_windows.ps1

Linux or WSL:

python3 -m venv .venv-wsl
.venv-wsl/bin/python -m pip install -e '.[dev]'
bash scripts/run_full_tests_linux.sh

See Contributing for the development workflow and Compatibility for the distinction between validated environments and planned host/model support.

Documentation

License and Attribution

ComfyUI-Sigmax is distributed under the MIT License. The project retains attribution for its audited source lineage in NOTICE.