docs/MODIFICATIONS.md

Modifications and attribution

Community MLX/Metal adaptation and distribution by Devin Lai, November 2026. This is an independent port, without MiniMax endorsement. No model pretraining, fine-tuning, new training data or quality calibration was performed.

• BF16: original transformer files, retained byte for byte. Native BF16 matrices and FP32 precision islands remain at their original precision.
• Packed12: the fifty main DiT blocks use the lossless h3-palette12-v1 layout. BF16 payloads are reconstructed before the native matrix operation. QKV storage follows the MLX Q/K/V ordering. This is storage compression, not 12-bit quantization. Native refiners are shared.
• Q8 / Q4: the fifty main blocks and two token-refiner blocks use MLX affine weight quantization, group size 64, with the required QKV reordering. Native support tensors and FP32 precision islands remain unquantized. Quantization changes generated images and can be slower than BF16.
• Shared support: native constants, normalization weights and native token refiners are repacked. The original timestep projections are evaluated once for the six released PDD steps, plus the fixed editing anchor. There is no interpolation or timestep skipping. These frozen tables were evaluated on Apple M5 Pro with MLX 0.32.4 and strict FP32 operations; the published loader checks the schedule, MLX version and precision environment.
• VAE and output heads: original files, unchanged. The default runtime follows the inspected BF16 decoder policy; its source weights are FP32.
• Text encoder: downloaded separately from the pinned official MiniMaxAI/MiniMax-H3 repository. It is not relicensed by this project.

The inference implementation follows the inspected SGLang and Transformers contracts. Apache-2.0 applies to this project's runtime code, with source identities in provenance/sources.json. Model weights and derivatives retain the MiniMax-H3-Image Community License Agreement. The separate text encoder retains the MiniMax H3 Community License Agreement. See LICENSE-model, LICENSE-text-encoder and NOTICE in the main repository, and LICENSE in each model component repository.