README.md

---
base_model: unsloth/gemma-4-12b-it
library_name: transformers
license: gemma
language:
  - en
tags:
  - gemma4
  - gemma4_unified
  - multimodal
  - tool-use
  - personal-assistant
  - qlora
  - merged
  - star
  - rejection-sampling
pipeline_tag: image-text-to-text
---

# Aria V9.2

**`google/gemma-4-12b-it`** fine-tuned into **Aria** — a personal assistant tuned for
**tool calling**, **memory-aware behaviour**, a **stable unprompted identity**, and now
**measurably better math** — with vision intact.

Merged standalone weights at the repo root (`from_pretrained` just works), the LoRA under
`adapter/`, GGUF quants under `gguf/`. Trained on a single RTX 3090 (24 GB); every teacher used
to generate training data was open-weight, so the corpus is legally clean.

---

## What's new: math actually moved

Math had been **stuck at 89/100 across five consecutive checkpoints**. Two attempts to shift it
failed. V9.2 moves it — and the gain was **replicated on a second, disjoint held-out sample**
before this model was released.

| Capability | Aria V9.1 | **Aria V9.2** |
|---|---|---|
| Math — fixed 100-item held-out set | 89 / 100 | **91 / 100** |
| Math — **fresh disjoint 150-item set** | 87.3 % | **92.0 %** |
| Math — pooled over all 250 held-out problems | 88.0 % | **91.6 %** |
| Tool calling | 10 / 10 | **10 / 10** |
| Identity (system-prompted) | 10 / 10 | **10 / 10** |
| Identity (unprompted) | 4 / 8 | **4 / 8** |
| Memory behaviour | 17 / 20 | **18 / 20** |
| Multimodal (vision) | pass | **pass** |

Nothing regressed.

> **On that memory 17→18.** One case on a 20-item suite is noise and is **not** part of the claim.
> It is reported because it happened, not because it means anything.

## Why the +2 wasn't trusted, and what was done about it

The first number was 91 vs 89 — a 2-point delta on 100 items, which is exactly the size of swing
this project has already been fooled by (a mid-run partial read of an earlier eval showed 91 % and
the final number landed on 89). Re-running the same eval would have proved nothing: the eval
serving path is **greedy** (`do_sample=False`), so identical inputs return byte-identical outputs.
A re-run is theatre, not evidence.

So a **confirmation set** was drawn: 150 GSM8K *test* problems, **disjoint from the 100-item eval
set** (disjointness asserted in code, not assumed), scored on both adapters back-to-back over the
same items. V9.2 led by **4.7 points — a larger gap than the original, in the same direction**.
Two independent samples agreeing is what turns a result into a finding.

## How: STaR (rejection-sampling SFT)

The corpus is **the model's own correct reasoning**:

1. Sample k=3 solutions at temperature 0.9 for 800 GSM8K **train** problems, from the V9.1 weights.
2. Keep a trace **only if its final answer matches gold**.
3. Fold the survivors into a single Stage-A training mix and train from base.

Result: **1,732 traces over 759 problems**, averaging 2.28 distinct solutions each.
Sampled pass@3 was **94.9 %** against greedy **88.6 %** — that ~6-point gap is the headroom STaR
is designed to harvest: problems the model *can* solve but doesn't do reliably in one shot.

**Data hygiene, verified programmatically before training:** zero overlap with the 100-item
held-out eval set, zero overlap with the *entire* GSM8K test split, every problem sourced from
train. If test had leaked, math would have jumped, the result would have looked like a triumph,
and every downstream number would have been worthless.

### Why this worked when DPO didn't

An earlier attempt used DPO on preference pairs mined from GSM8K train. It **trained correctly** —
held-out preference accuracy 0.875, reward margins +0.72; it genuinely learned to rank the right
answer above its own wrong one — and produced a **clean null**: every capability score came back
identical.

The likely reason is a **style confound**. "Chosen" was terse human gold rationale, stylistically
nothing like the model's own verbose reasoning, so what was rewarded and what was produced were
different objects; it plausibly learned *"prefer terse gold-style text"* rather than *"reason
correctly."* STaR removes that confound entirely — same voice, same format, correct reasoning.
**The mechanism was the difference, not the effort.**

### Data mix (single stage)

| Source | Rows | Purpose |
|---|---|---|
| `tools.jsonl` | 4,000 | tool-calling behaviour |
| `memory.jsonl` | 1,915 | memory-aware behaviour |
| `identity.jsonl` ×2 | 2,000 | unprompted identity — trained jointly, never as a repair pass |
| `curiosity.jsonl` | 800 | disposition |
| **`star_math.jsonl`** | **1,804** | **her own verified-correct GSM8K solutions** |
| multimodal floor | 3,000 | prevents vision degradation |
| replay pool | 1,600 | general-capability retention |
| **Total** | **14,664 train / 453 eval** | |

```python
r = 32, lora_alpha = 32, lora_dropout = 0.0, bias = "none"
target_modules = ["q_proj","k_proj","v_proj","o_proj",
                  "gate_proj","up_proj","down_proj",
                  "lm_head","embed_tokens"]
finetune_vision_layers = True     # encoder-free: shared weights must stay trainable
epochs 2 · effective batch 16 · lr 1e-4 cosine · 1,834 steps · train_loss 0.5679
```

Train loss came out at **0.5679 against V9.1's 0.572** — near-identical, which matters: it means
the model was *not* simply memorising its own easy output.

`gemma-4` is `gemma4_unified`, an **encoder-free multimodal** model where vision, audio and text
share weights. There is no vision tower to freeze, so the multimodal floor is load-bearing.

## Identity, and a rule worth stating

V8 shipped unable to name itself unprompted — asked "who made you?" with no system prompt it said
*"I am Gemma 4, developed by Google DeepMind."* Its identity eval scored 9/10 because that eval
supplied the answer in the system prompt. **An identity eval that tells the model the answer
measures nothing.**

Two attempts to repair this on the finished adapter both failed, costing 6–8 points of math each
time. The fix was to train identity **jointly in the first pass** (V9.1), which cost nothing.
A separate composable identity adapter was also built and **rejected** — it halved unprompted
identity, because the `lm_head`/`embed_tokens` exclusion that made it safe also made it unable to
change what the model says it is.

**The rule: identity goes in the first pass, or not at all.**

## Usage

> **Requires `transformers` 5.15.0.dev0 (from source).** Stock `transformers` <= 5.5.0 cannot load
> `gemma4_unified`.

```python
import transformers.integrations.heterogeneity.configuration_utils as het

# gemma4_unified has a HETEROGENEOUS per-layer config; reading a global attr that
# varies per layer raises AmbiguousGlobalPerLayerAttributeError. Install this shim
# BEFORE loading, or most loaders will fail.
_HCM, _Err = het.HeterogeneousConfigMixin, het.AmbiguousGlobalPerLayerAttributeError
_orig = _HCM.__getattribute__
def _permissive(self, key):
    try:
        return _orig(self, key)
    except _Err:
        self.__dict__["allow_global_per_layer_attribute_access"] = True
        return _orig(self, key)
_HCM.__getattribute__ = _permissive

from transformers import AutoProcessor, AutoModelForCausalLM

model = AutoModelForCausalLM.from_pretrained("SurgeFF/AriaV9.2", device_map="auto")
processor = AutoProcessor.from_pretrained("SurgeFF/AriaV9.2")
```

GGUF: `gguf/` holds `Q8_0`, `Q6_K`, `Q5_K_M`, `Q4_K_M`, `Q4_0` plus **`AriaV92-mmproj-F16.gguf`,
which is required for vision** — without it the GGUF is text-only. The full-precision F16 text
GGUF is deliberately not shipped (same precision as the root safetensors; it would double the repo
for no benefit).

Tool calls use the trained convention:

```
<tool_call>{"name": "recall", "arguments": {"query": "..."}}</tool_call>
```

## Limitations

- **Unprompted identity is 4/8.** Asked cold, with no system prompt and no memory, she still fails
  to name herself about half the time. A system prompt or memory layer covers this in practice —
  but those *mask* the gap rather than close it.
- **Math is ~92 % on GSM8K-style problems.** Not evaluated on MATH, competition problems, or long
  symbolic derivation. The remaining errors are decode-time reliability, not missing knowledge:
  sampled pass@3 (94.9 %) still exceeds greedy accuracy.
- **Not a general-purpose assistant release.** Tuned for one person's fleet, tools and conventions.
- **Memory behaviour is not a memory system.** The model is trained to *behave* correctly around
  memory; it has none of its own. You supply the tools and the store.
- **Tool schema is specific** to five tools (`remember`, `recall`, `exec`, `web_search`,
  `send_message`). Generalisation to arbitrary schemas is untested.
- **Vision is verified, not optimised.** The multimodal floor prevents regression; the eval is a
  smoke test, not a VQA benchmark.

## Things that did not work

Recorded because negative results are the useful part. All were fully trained, evaluated, and
declined under a promotion rule fixed *before* the numbers were seen.

| Experiment | Result | Decision |
|---|---|---|
| Stage B (integration) | memory +1, **math 89→84** | rejected |
| Memory top-up | memory 17→18 (noise), **math 89→85** | rejected |
| Math DPO | **identical on every capability** despite pref-acc 0.875 | rejected — null |
| Identity repair pass ×2 | identity_bare 0→5/8 and 0→4/8, but **math 89→83 / 89→81** | rejected |
| Layer-2 identity adapter | **identity_bare 4/8→2/8** | rejected |
| **STaR math (this release)** | **math 89→91, replicated 87.3 %→92.0 % on fresh data** | **promoted** |

Six rejections, one promotion. The rejections are why the promotion means something.

## License

Derived from `google/gemma-4-12b-it`, governed by the
**[Gemma Terms of Use](https://ai.google.dev/gemma/terms)**. Training data was generated
exclusively with open-weight teacher models.

## Citation

```bibtex
@misc{aria-v92,
  title  = {Aria V9.2: STaR-improved math on a tool-using, memory-aware Gemma-4-12B assistant},
  author = {Williams, Sergio},
  year   = {2026},
  url    = {https://huggingface.co/SurgeFF/AriaV9.2}
}
```