---
language:
  - en
  - zh
license: apache-2.0
library_name: transformers
base_model: Qwen/Qwen3-1.7B
tags:
  - bija
  - cerebellum
  - lora
  - distillation
  - mlx
  - gguf
  - memory
  - qwen3
pipeline_tag: text-generation
---

# BIJA-cerebellum-Qwen3-1.7B-v1

LoRA-distilled variant of [Qwen/Qwen3-1.7B](https://huggingface.co/Qwen/Qwen3-1.7B), fine-tuned to power the **cerebellum** (small-brain) of [Bīja](https://github.com/cxyAI/bija) — a memory-system-as-AI built on the eight-consciousness theory.

The cerebellum runs continuously alongside Bīja's daemon, performing low-latency memory routing decisions: **classify intent**, **judge memory-worthiness (memorize)**, and **arbitrate write-time conflicts (UPDATE / DELETE / NONE)** when new facts collide with existing seeds. The base 1.7B model handled most of these well — except for **paraphrase detection**, where it correctly identified only **17%** of cross-language / synonym / abbreviation duplicates as `NONE`. This adapter fixes that to **100%**.

## Why this model exists

Bīja's 30-day case eval (`bija/eval/cerebellum-{memorize,arbitrate}/benchmark.json`) revealed three structural issues that **prompt-only iteration cannot fix**:

| Task | Baseline 1.7B | Symptom | Root cause |
|---|---|---|---|
| arbitrate NONE-duplicate | 17% (1/6) | Paraphrases (cross-lang / synonym / abbreviation) misjudged as `UPDATE` | Training prior: prefer emitting an "action" over `NONE` |
| memorize FN | 13.3% | Valuable seeds (lessons / corrections) misjudged as `SKIP` | Conservative SAVE bias |
| memorize FP | 3.3% | Some commit-style logs slip through as `SAVE` | Same prior, opposite direction |

A separate experiment with [Granite 3.3-2B](https://huggingface.co/ibm-granite/granite-3.3-2b-instruct) ran 4 prompt-rewrite iterations across 120 cases and confirmed the same prior cannot be undone by prompts alone. **Behavioral-cloning LoRA distillation from a Qwen3-4B teacher** was the next path.

## Results

Evaluated on the same 120 + 30 case benchmark used by the production cerebellum (`bija/eval/cerebellum-memorize/run.ts` + `bija/eval/cerebellum-arbitrate/run-with-sim.ts`):

| Metric | Baseline (Qwen3-1.7B-Q8_0 prompt-only) | LoRA Q8_0 GGUF | Δ |
|---|---|---|---|
| memorize accuracy | 91.7% (110/120) | **97.4%** (excl 5 cold-start parse-fails) | **+5.7pp** |
| memorize FP rate | 3.3% | 3.3% | 0 |
| memorize FN rate | 13.3% | **1.7%** | **−11.6pp** |
| memorize avg latency | 480ms | **436ms** | **−9%** |
| arbitrate accuracy | 76.7% (23/30) | **86.7%** (26/30) | **+10pp** |
| **arbitrate NONE-duplicate** | **17%** (1/6) | **100%** (6/6) | **+83pp** |
| arbitrate avg latency | ~1500ms | **1097ms** | **−27%** |

Notably the LoRA-tuned Q8_0 GGUF is **faster** than the baseline Q8_0 GGUF — a side-effect of distillation: the model emits canonical JSON without preamble or thinking blocks, reducing total generated tokens.

**A more detailed comparison vs the MLX fp16 evaluation is in the project repo's [Phase 5 wrap-up](https://github.com/cxyAI/bija/blob/main/docs/path-b-wrap-up-2026-04-26.md).**

## Files in this repo

| File | Purpose |
|---|---|
| `Qwen3-1.7B-BIJA-cerebellum-Q8_0.gguf` (1.7 GB) | Drop-in Q8_0 GGUF; `llama.cpp` / Ollama / cerebellum-style sidecars load it directly |
| `adapters.safetensors` (38 MB) | Raw LoRA weights — apply on top of vanilla `Qwen/Qwen3-1.7B` (HF format) with `mlx_lm.fuse` or `peft` |
| `adapter_config.json` | mlx-lm LoRA config: rank=16, scale=2.0, dropout=0.05, num_layers=16, target=`q_proj+v_proj` |

## How to use

### Drop-in replacement (recommended) — llama.cpp / Ollama

```bash
hf download doncxy/BIJA-cerebellum-Qwen3-1.7B-v1 \
  Qwen3-1.7B-BIJA-cerebellum-Q8_0.gguf \
  --local-dir ~/models

llama-server -m ~/models/Qwen3-1.7B-BIJA-cerebellum-Q8_0.gguf -c 4096
```

Or for Bīja users — replace the production GGUF directly:

```bash
mv ~/.seeddb/cerebellum/models/Qwen3-1.7B-Q8_0.gguf{,.baseline}
ln -s ~/models/Qwen3-1.7B-BIJA-cerebellum-Q8_0.gguf \
      ~/.seeddb/cerebellum/models/Qwen3-1.7B-Q8_0.gguf
pkill -f llama-server   # next call respawns sidecar with new weights
```

### Apply LoRA on top of vanilla Qwen3-1.7B (MLX)

```bash
pip install mlx-lm
hf download doncxy/BIJA-cerebellum-Qwen3-1.7B-v1 \
  adapters.safetensors adapter_config.json --local-dir ./bija-cerebellum-lora

mlx_lm.generate \
  --model Qwen/Qwen3-1.7B \
  --adapter-path ./bija-cerebellum-lora \
  --prompt "Decide whether this text is worth saving as long-term memory..." \
  --max-tokens 128
```

## Training recipe

| Field | Value |
|---|---|
| Base model | `Qwen/Qwen3-1.7B` (1.72B params) |
| Teacher | `Qwen/Qwen3-4B` (Q8_0 GGUF, behavioral cloning via local `llama-server`) |
| Distillation | Behavioral cloning — teacher generates SFT data, filtered by gold labels |
| Dataset | 137 SFT samples (104 train / 33 valid), stratified by task × category |
| Trainable params | **9.96M** (0.579% of base) |
| LoRA rank / scale | 16 / 2.0 (effective alpha 32) |
| LoRA dropout | 0.05 |
| Target modules | `q_proj` + `v_proj` (mlx-lm default) |
| LoRA layers | last 16 of 28 transformer blocks |
| Batch size | 4, max-seq 4096 |
| Iterations | 600 (~52 min on Apple M2 Pro 64 GB) |
| Optimizer / LR | Adam / 1e-4 |
| Final train loss | 0.006 |
| Best val loss | 0.077 (iter 350); final 0.086 |
| Peak memory | 33.3 GB / 64 GB (fp16, no QLoRA / no grad checkpoint) |
| Tokens/sec | ~820 avg |

## Intended use

Designed for the Bīja project's cerebellum role: **JSON-only, low-latency routing decisions** for memory operations. The system prompts the model expects are project-specific (see `seeddb/packages/sdk/src/cerebellum/prompts.ts` in the source repo) — they enumerate SAVE/SKIP categories for `memorize` and UPDATE/DELETE/NONE rules for `arbitrate`.

This is **not** a general-purpose chat model. Outside Bīja's prompt distribution, behavior may regress versus the base Qwen3-1.7B. For general use, prefer the base model.

## Limitations

- **Trained on 137 samples** — task ceiling closely tracks the Qwen3-4B teacher; `MIXED` and certain `UPDATE-relational` cases inherit teacher errors.
- **Cold-start parse failures** — first ~5 sidecar requests after spawn may miss the 500 ms timeout (warmup). Persistent daemons amortize this away.
- **Production daemons only** — short-lived spawns will hit cold-start every time.
- **Q8_0 quantization** loses ~3pp arbitrate accuracy versus fp16 MLX; use the safetensors adapter on fp16 base if you need maximum accuracy.

## Citation / acknowledgements

Built on:
- [`Qwen/Qwen3-1.7B`](https://huggingface.co/Qwen/Qwen3-1.7B) (base)
- [`Qwen/Qwen3-4B`](https://huggingface.co/Qwen/Qwen3-4B) (teacher; via local Q8_0 GGUF)
- [`mlx-lm`](https://github.com/ml-explore/mlx-lm) (training + fuse)
- [`llama.cpp`](https://github.com/ggerganov/llama.cpp) (HF→GGUF conversion)

## License

Apache 2.0 (matches base model).