deepseek4-quantize.c: C HF-safetensors to GGUF quantizer.
quants.[ch]: the deliberately small local quantization implementation used by the quantizer. It implements the DS4 output formats we actually ship: q8_0, q4_K, q2_K, and iq2_xxs.
imatrix/: dataset and instructions for collecting routed-MoE activation importance with ds4.
quality-testing/: prompts and scripts used to compare local GGUF variants against official DeepSeek V4 Flash continuations.

Build

make -C gguf-tools

The quantizer is plain C and does not link GGML. GGUF metadata handling, safetensors loading, FP4/FP8 dequantization, and the quantizers used by our Q2 and Q4 recipes live in this directory.

Generate An Imatrix

First regenerate or inspect the calibration dataset:

python3 gguf-tools/imatrix/dataset/build_ds4_imatrix_dataset.py

Then collect activation statistics with the DS4 runtime:

./ds4 \
  -m gguf/DeepSeek-V4-Flash-Q4KExperts-F16HC-F16Compressor-F16Indexer-Q8Attn-Q8Shared-Q8Out-chat-v2.gguf \
  --imatrix-dataset gguf-tools/imatrix/dataset/rendered_prompts.txt \
  --imatrix-out gguf/DeepSeek-V4-Flash-chat-v2-routed-moe-ds4.dat \
  --ctx 32768

The imatrix file is useful immediately with this DS4 quantizer. Generic GGUF tools need DS4-specific tensor-name mapping and per-expert slicing before they can use it correctly. The accepted imatrix format is the legacy llama.cpp binary .dat file emitted by ds4 --imatrix-out.

Generating this .dat file locally is possible, but slow: it runs the DS4 prefill graph over the full calibration corpus and reads routed-MoE activation statistics back from the GPU. The latest published imatrix-generated GGUF files are available in the antirez Hugging Face repository:

https://huggingface.co/antirez/deepseek-v4-gguf/tree/main

Generate Q2 And Q4 GGUFs

The template GGUF supplies metadata, tokenizer, tensor order, and logical shapes. Tensor bytes are regenerated from the Hugging Face safetensors. Full generation is intentionally offline and heavy: expect roughly 80-90 GB outputs for the 2-bit template family and roughly 150-170 GB for the 4-bit routed-expert family, plus enough free disk for the temporary output. Use --dry-run and --compare-tensor before starting a full write, and use --overwrite only when you really mean to replace an existing GGUF.

Q2 routed experts with imatrix:

gguf-tools/deepseek4-quantize \
  --hf ../deepseek-v4-quants/hf/DeepSeek-V4-Flash \
  --template gguf/DeepSeek-V4-Flash-IQ2XXS-w2Q2K-AProjQ8-SExpQ8-OutQ8-chat-v2.gguf \
  --out gguf/DeepSeek-V4-Flash-IQ2XXS-w2Q2K-AProjQ8-SExpQ8-OutQ8-chat-v2-imatrix.gguf \
  --imatrix gguf/DeepSeek-V4-Flash-chat-v2-routed-moe-ds4.dat

Q4 routed experts with imatrix:

gguf-tools/deepseek4-quantize \
  --hf ../deepseek-v4-quants/hf/DeepSeek-V4-Flash \
  --template gguf/DeepSeek-V4-Flash-Q4KExperts-F16HC-F16Compressor-F16Indexer-Q8Attn-Q8Shared-Q8Out-chat-v2.gguf \
  --out gguf/DeepSeek-V4-Flash-Q4KExperts-F16HC-F16Compressor-F16Indexer-Q8Attn-Q8Shared-Q8Out-chat-v2-imatrix.gguf \
  --imatrix gguf/DeepSeek-V4-Flash-chat-v2-routed-moe-ds4.dat

You can override tensor families:

--experts iq2_xxs
--routed-w2 q2_k
--attention-proj q8_0
--shared q8_0
--output q8_0

Useful checks before writing a full model:

gguf-tools/deepseek4-quantize \
  --hf ../deepseek-v4-quants/hf/DeepSeek-V4-Flash \
  --template MODEL.gguf \
  --compare-tensor blk.0.attn_q_a.weight

--compare-tensor regenerates a single tensor and byte-compares it against the template or --compare-gguf. --threads N controls routed-expert workers.

When No Imatrix Is Given

iq2_xxs requires an importance vector. If --imatrix is not provided and the target type requires one, deepseek4-quantize computes a synthetic fallback from the dequantized weight itself:

importance[column] = sum(row[column]^2) over all rows

This is a weight-energy heuristic. It is not as good as measuring real DS4 activations, but it gives the quantizer a stable column weighting and was good enough for the first working 2-bit GGUFs.

Quality Testing

See quality-testing/README.md. The short version is:

python3 gguf-tools/quality-testing/collect_official.py
make -C gguf-tools quality-score
gguf-tools/quality-testing/score_official MODEL.gguf gguf-tools/quality-testing/data/manifest.tsv /tmp/model.tsv 4096
python3 gguf-tools/quality-testing/compare_scores.py /tmp/old.tsv /tmp/new.tsv