Jebadiah 4B v2 MLX

MLX builds of Jebadiah 4B v2 for Apple silicon, one folder per precision (8bit/, 4bit/, group size 64). Jebadiah answers a typed question (choice, noul or score) with a probability for every option, read from one forward pass. Nothing is generated. Code, trainer and evals: getainode/jebadiah.

Files

Every file was checked on the 260 held-out questions the merged weights were checked on, and compared with the merged bf16 weights and with the training run's own eval records.

File	Size	Same answer as bf16	Same as the run	choice + noul	score	Prob. diff median / max
`8bit/`	4.5 GB	252 / 260	253 / 260	169 / 173	84 / 87	0.004 / 0.110
`4bit/`	2.4 GB	215 / 260	215 / 260	157 / 173	58 / 87	0.056 / 0.380
bf16 weights			259 / 260	172 / 173	87 / 87	0.002 / 0.019

Which one: 8bit if your Mac has the memory; 4bit when it does not. A folder needs about its own size in unified memory, plus about 1 GB for a 2k-token prompt.

8bit changes 8 of 260 answers against bf16 (3 on score questions) and moves probabilities more (median 0.004, max 0.11). Use it only when a larger build does not fit. 4bit changes 45 of 260 answers against bf16 (29 on score questions) and moves probabilities more (median 0.056, max 0.38). Use it only when a larger build does not fit.

Run it

The script renders the prompt exactly as AINode does, runs one forward pass with mlx-lm, multiplies the last hidden state by the option labels' output-head rows in fp32 and applies temperatures.json (choice 1.1167, noul 1.3319, score 1.1974). Needs mlx-lm 0.31 or newer (qwen3_5 support).

pip install "mlx-lm>=0.31"
hf download frontier-infra/jebadiah-4b-v2-MLX --include "8bit/*" "scripts/*" temperatures.json --local-dir jebadiah-4b-v2-MLX
cd jebadiah-4b-v2-MLX
python scripts/decide_mlx.py --model 8bit --request scripts/example-request.json

--no-temperatures returns the raw probabilities.

On example-request.json (8bit/):

{
 "route": {"type": "choice", "choice": "billing", "confidence": 0.394292, "probabilities": {"billing": 0.596195, "support": 0.0839, "sales": 0.319905}},
 "urgent": {"type": "noul", "noul": 0.147991}
}

How it was measured

Jevals PubMedQA, Banking77 (77 options) and HelpSteer2, plus Nimble: the merge check's fixed sample (seed 20260925), the run's option order and temperatures. "Same answer" is the top option; "prob. diff" is the largest change on any option against the run's CUDA record. Records: eval/agreement-*.json.