KAT-Coder-V2.5-Dev — MTP GGUFs

KAT ships mtp_num_hidden_layers: 0 — no draft head. These builds graft Qwen3.6-35B-A3B's original MTP head onto KAT's trunk, quantized with an imatrix calibrated on KAT's own output.

Includes the bf16 master so you can build any tier yourself without a 69 GB safetensors pull or a conversion.

Which head is in here, and why it matters

We fine-tuned this head twice on KAT's own rollouts. Both fine-tunes made it worse. Measured live on 79 configs, same tier, same flags, only the head differing:

MTP head	COPY	NOVEL	AGENTIC
Qwen donor (shipped here)	76%	48%	73%
our fine-tune, 450 steps	50%	24%	46%
our fine-tune, 80 steps	47%	37%	45%
(reference) Qwen head on Qwen's own trunk	89%	53%	76%

Draft acceptance, --spec-type draft-mtp, DraftMax 2, temp 1.0 / top_k 20 / top_p 0.95 / presence_penalty 1.5.

The donor head on KAT is within 3 points of Qwen's own co-trained head on its own trunk. There is essentially no trunk-swap penalty. Every file here carries that head, verified byte-identical to the donor at build time:

donor-head sha256  faac91f15cbe54475faa2578bedc46a7c29a947b8a3e7ef3ecd376ae079826ab
blk.40.nextn.hnorm.weight  sha256  6dda2c53989ed9a8   <- fingerprint, verify yours

Files

tier	recipe
`UD-IQ4_XS`	Unsloth Dynamic 2.0
`UD-Q4_K_XL`	Unsloth Dynamic 2.0
`UD-Q5_K_S`	Unsloth Dynamic 2.0
`UD-Q6_K`	Unsloth Dynamic 2.0
`APEX-I-Mini`	mudler APEX
`APEX-I-Compact`	mudler APEX
`APEX-I-Quality`	mudler APEX
`APEX-I-Balanced`	mudler APEX
`APEX-I-Compact-v2D-lite`	mudler APEX + v2D-lite
`BF16/*-00001..2-of-00002.gguf`	bf16 master, MTP embedded
`original-mtp-head.safetensors`	the head alone, for re-grafts

Every map was read from that tier's own published GGUF header — none assumed, none shared between tiers.

v2D-lite is applied to I-Compact only. It raises attn_k/attn_v on the 10 full-attention layers and output.weight, funded by token_embd. Unsloth's maps already sit at Q8_0 on all of those, so applying it there would only lower token_embd — measurably worse, so we didn't.

Serving

llama-server -m <model>.gguf -c 65536 -fa on --jinja \
  --spec-type draft-mtp,ngram-mod \
  --spec-draft-n-max 1 --spec-draft-n-min 0 --spec-draft-p-min 0.75 \
  --spec-ngram-mod-n-min 8 --spec-ngram-mod-n-max 24 --spec-ngram-mod-n-match 48

Found by coordinate ascent over 79 live configs. Measured, RTX 3070 Ti Laptop 8 GB, 35 of 40 MoE layers on CPU:

workload	t/s	draft acceptance
copy-heavy	71.0	97%
agentic	33.0	64%
novel prose	33.9	81%

Two knobs carry most of it:

--spec-draft-p-min 0.75 — the highest-leverage setting found. Drafting only when confident turns a mediocre head into a useful one.
draft-mtp + ngram-mod together. Either alone is far worse: on this hardware MTP alone is a net loss versus no speculation. With ngram, every head reaches 96-97% on copy — ngram covers the repeats, and the head covers the rest.

--spec-draft-n-max 1 beat 2 and 3: a longer MTP chain starves ngram-mod's dispatch opportunities.

Building your own tier

No conversion, no graft, no 69 GB pull:

hf download gbuzhf/KAT-Coder-V2.5-Dev-MTP-GGUF --include "BF16/*" --local-dir .
llama-gguf-split --merge BF16/Kwaipilot_KAT-Coder-V2.5-Dev-BF16-MTP-00001-of-00002.gguf master.gguf
llama-quantize --imatrix imatrix.gguf --tensor-type-file your_map.txt master.gguf out.gguf Q4_K_M

Known limitation

No imatrix contains statistics for blk.40 — llama-imatrix never executes the MTP head during a forward pass. That block is quantized unguided in every build, ours and everyone else's.

Credits

Kwaipilot — KAT-Coder-V2.5-Dev · Qwen — Qwen3.6-35B-A3B base and the MTP head · Unsloth — Dynamic 2.0 maps · mudler — APEX maps · bartowski — calibration corpus · llama.cpp

License: apache-2.0, inherited from the base model.