The project
This adapter comes out of a campaign teaching fleets of AI coding agents to
reconstruct shipped game binaries byte-for-byte — matching
decompilation, the console-preservation community's gold standard: rewrite
C++ until the original vintage compiler, at the original flags, reproduces
the retail machine code exactly. In that campaign, agent swarms byte-matched
over 44,000 functions of a stripped retail Xbox 360 binary in about ten
weeks — with every proposal judged by the real compiler and
objdiff, never by a model. Start
with the flagship write-up
and the methodology post;
the full project context lives on
the r32 card,
which is the primary release of this pair.
Why publish a twin
The family has run this experiment before:
v13-chain r64
vs r32 was a measured null — doubled adapter capacity at fixed data
bought nothing detectable at 9B — and a later internal rank ladder (v16) was
flat as well. That history is exactly why the r32 arms are this generation's
primaries. But v17's supply is qualitatively different from anything those
rank experiments trained on (multi-turn trajectories to ~87k tokens, tool
calls, recovery sequences), so the project re-ran the twin rather than
assuming the null transfers.
No verdict exists yet: unlike the v13 pair, neither v17 arm has been
evaluated, so this pair currently offers matched artifacts, not a
measured contrast. Both repos' training-job-written PUBLISHED.json pin the
same corpus sha256, so the corpus difference is provably zero for anyone who
wants to run the comparison.
Honest status notes
Published as a research artifact with its evidence stated plainly:
- No evaluation has been run on this adapter yet — nor on any v17 arm.
Until numbers land,
v14-evalformat
remains the measured pick for the multi-turn feedback loop.
- Training loss learned cleanly (1.03 → 0.48 over 190 optimizer steps,
2 epochs; min 0.42) — a supervision readout, not an evaluation claim, and
the small gap to the r32's 0.52 endpoint is not evidence of capability.
- "full" means all admissible trajectory rows, including tool-use turns
from teacher sessions that did not end byte-exact; the byte-exact-only
filter is the sibling
v17-matched arm.
- Single training seed (42) — any future r32-vs-r64 verdict is
provisional under the project's multi-seed rule.
- The adapter is ~2× the r32's size (660 MiB vs 330 MiB safetensors) for,
on prior rank-ladder evidence, likely the same capability — prefer the
r32 for actual decompilation work unless you are studying capacity.
Model facts
Table | |
|---|
| base | Qwen/Qwen3.5-9B (apache-2.0) |
| method | LoRA r=64, α=128, dropout 0.05, all-linear, bf16 |
| corpus | 3,032 tool-trajectory rows (v17full.jsonl, sha 411cfaed…) — byte-identical to the r32 arm |
| window | 90,112 tokens max_seq (zero rows dropped) |
| schedule | 2 epochs, 190 steps, eff. batch 32, linear LR, seed 42 |
| trained | 2026-08-31 |
| format | Qwen3.5 chat template, thinking ON, native XML tool calls |
Training data
The corpus is the project's 2026-08-30/31 teacher-mint union: multi-turn
trajectories where a tool-armed teacher (GLM-5.3-flash) works decompilation
targets from a private Halo: Combat Evolved Anniversary (Xbox 360)
reconstruction effort through the project's compile-and-score harness —
reading disassembly, proposing C++, compiling with the real toolchain, and
reacting to objdiff feedback across turns (up to 8). Trajectories are
converted at tool-turn granularity, holdout-gated at translation-unit grain
against the project's eval sets, and student-rendered through Qwen3.5-9B's
own tokenizer template.
The completions are therefore teacher-model-generated text plus tool-call
structure; the surrounding context (assembly, diffs, compiler output)
derives from that private reconstruction effort, which is not publicly
linkable. No license claim is made for the corpus; it is not published. The
shipped PUBLISHED.json pins the corpus file's sha256
(411cfaedcae6…, 3,032 rows) as provenance.
How to use it
from transformers import AutoModelForCausalLM, AutoTokenizer
from peft import PeftModel
base = AutoModelForCausalLM.from_pretrained("Qwen/Qwen3.5-9B", dtype="bfloat16", device_map="auto")
tok = AutoTokenizer.from_pretrained("Qwen/Qwen3.5-9B")
model = PeftModel.from_pretrained(base, "freeqaz/decomp-synth-lifter-v17-full-qwen3.5-9b-r64-lora")
This adapter is trained for agentic tool use: serve it behind an
OpenAI-compatible endpoint with tool calling enabled and give it compile /
diff / read tools. With vLLM:
vllm serve Qwen/Qwen3.5-9B --enable-lora \
--lora-modules v17r64=freeqaz/decomp-synth-lifter-v17-full-qwen3.5-9b-r64-lora \
--enable-auto-tool-choice --tool-call-parser qwen3_coder
The tool-call parser flag matters: the adapter emits tool calls in the
Qwen3.5 template's native XML form, which qwen3_coder parses; without it
(or with a JSON-style parser) the calls degrade silently into plain text.
Like every adapter in this family, it is a proposal engine for a
compile-and-score loop — sample multiple candidates, compile each with the
target project's real toolchain, and let objdiff judge. Byte-exact is the
only acceptance criterion. Training rows ran up to ~87k tokens of session
context, so give it a long context window. In bf16 the 9B base fits a
single 24 GB GPU.
The adapter family
Table with columns: adapter, base, format, role| adapter | base | format | role |
|---|
| v10 | Qwen3.6-27B | RAW | single-turn matcher, reference 27B |
| gtp0c | Qwen3.8-27B | RAW | v10 recipe verbatim on the newer base (matched pair) |
| v13-chain r32 | Qwen3.5-9B |
Integrity
PUBLISHED.json (shipped) carries per-file sha256 written by the training
job at publish time. Two internal metadata files it pins
(train_summary.json, artifact-manifest.json) are retained in the
project's artifact store but not shipped here — they carry training-box
paths. adapter_config.json was rewritten post-training to the HF base id;
original bytes at provenance/adapter_config.orig.json.
License
Adapter weights: Apache-2.0. A model trained to reproduce shipped game
code can reproduce shipped game code — that is its purpose; decompilation
projects operate in a long-standing community norm of clean-room
reconstruction for interoperability and preservation.