Extends the v0.38.0 train-time quantization menu (gptq / awq / hqq:Nbit /
aqlm / eetq / mxfp4 / fp8) from SFT-only to all 11 transformer-backend
trainers (DPO / GRPO / KTO / ORPO / SimPO / IPO / PPO / RewardModel /
Pretrain / Embedding / BCO). Closes the v0.38.0 known gap.
Schema gate: SoupConfig._validate_quant_menu_supported_tasks removes the
`task != "sft"` rejection branch. MLX backend rejection retained with
distinct message; modality=text gate retained (vision/audio Quant Menu
deferred — modality-specific kwargs not yet threaded through the unified
loader).
Trainer wiring (11 sites): each non-SFT _setup_transformers replaces the
inline BitsAndBytesConfig(load_in_4bit=True, ...) block with a call to
build_quantization_config_for_loader(tcfg=tcfg, base=cfg.base, console=console)
— mirrors sft.py:420-440 exactly. kbit-prep tuple widened from
("4bit", "8bit") to ("4bit", "8bit", "mxfp4"). BitsAndBytesConfig import
removed from each non-SFT trainer.
Review fix — PPO reward model: _load_reward_model gains optional tcfg
kwarg; when supplied, the reward checkpoint loads with the same Quant
Menu config as the policy. Both PPO call sites forward tcfg=tcfg.
Defends against silent fp16 OOM on a GPTQ/AWQ/HQQ policy run.
Review fix — defence-in-depth: new TrainingConfig.reward_model field
validator rejects null bytes and caps length at 512 chars (matches
cfg.base policy). The Quant Menu loader's per-call null-byte check
in _check_local_marker remains as the runtime backstop.
Tests: +131 net new (4930 -> 5061). New tests/test_v0405_part_a.py
parametrizes 11 tasks x 7 quant formats; covers MLX rejection per task,
quantization_aware x Quant Menu cross-validator regression for non-SFT,
source-level invariants (no inline BNB literal, kbit tuple regex),
and a live mock-based dispatch test for _load_reward_model proving the
Quant Menu path is reachable when tcfg is supplied and skipped when
tcfg=None.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Train-time support for 7 new quantization formats — close the width gap
with LlamaFactory. Wired into SFT trainer + transformers backend + text
modality; multi-trainer/modality expansion deferred to v0.38.1 (mirrors
v0.27.0 MII / v0.37.0 multipack stub-then-live pattern).
- Part A — GPTQ: quantization='gptq' + gptq_disable_exllama (PEFT triton)
- Part B — AWQ: quantization='awq' + GEMM/GEMV builder
- Part C — HQQ: hqq:1bit..hqq:8bit (no 7bit; not supported upstream)
- Part D — AQLM: locked-2-bit
- Part E — EETQ: locked-8-bit
- Part F — MXFP4 + FP8 dequantize-on-load
- Part G — bnb_4bit_quant_storage for FSDP+QLoRA
("crucial for fsdp+qlora" — LlamaFactory quantization.py:178)
- Part H — check_quant_distributed_compat matrix + docs/QUANTIZATION.md.
HQQ/EETQ/AQLM x {FSDP, ZeRO-3} hard-fail; BNB-4bit + FSDP without
quant_storage warns. Wired into commands/train.py startup.
Three new schema validators:
- _validate_prequantized_no_qat — pre-quantized + QAT incompatible
- _validate_bnb_quant_storage_only_with_4bit — silent no-op guard
- _validate_quant_menu_supported_tasks — sft + transformers + text gate
Net: +61 tests (4374 -> 4435). Four review-agent waves clean before tag
(python-review / code-review / security-review / tdd-guide);
verification-loop performed as manual equivalent per CLAUDE.md allowance.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Alpamys