license: gemma base_model:

• google/gemma-4-E2B-it library_name: transformers pipeline_tag: text-generation language:
• en tags:
• abliterated
• uncensored
• decensored
• refusal-direction
• gemma4
• direct-steering
• safetensors datasets:
• mlabonne/harmless_alpaca
• mlabonne/harmful_behaviors metrics:
• keyword_rate_refusals
• kl_divergence model-index:
• name: gemma-4-E2B-it-abliterated results:
  • task: type: text-generation dataset: name: mlabonne/harmful_behaviors (test[:100]) type: mlabonne/harmful_behaviors metrics:
    • name: Refusals (KeywordRate) type: refusals value: 4/100
    • name: KL divergence vs base (3 tokens) type: kl_divergence value: 2.9072

Gemma-4-E2B-it · Abliterated (direct steering)

This is google/gemma-4-E2B-it with its refusal behavior removed via directional ablation — no fine-tuning, no retraining, weights edited in place. Refusal rate dropped from 99/100 to 4/100 on the standard evaluation set while keeping the base weights otherwise intact.

Everything (data, parameters, seed) needed to reproduce this exact run byte-for-byte is included in the repository — see Reproduction.

Honest note on quality: the selected trial sits on the aggressive end of the Pareto front (fewest refusals, largest distribution shift). KL of 2.9 is relatively high — if you notice capability degradation, milder variants are available, see Pareto front & milder variants.

Model description

• Base model: google/gemma-4-E2B-it — multimodal Gemma 4 (text + vision + audio towers, 35 text layers, hidden size 1536, vocab 262 144).
• Only the text tower was modified. All 35 decoder layers had their attention/MLP projections projected along the computed refusal direction. Vision and audio encoders are untouched original weights; the full multimodal config is preserved.
• Method: Anlord Abliterator 1.6.0 (native backend, steering_mode=direct) — weights are edited in place, no LoRA adapters. The refusal direction is derived per-component from residual streams of 400 harmless vs 400 harmful prompts (mean method, orthogonalized against the harmless mean), with input-side ablation, Gaussian decay kernel and winsorization at q=0.995.
• Search: Optuna TPE, multi-objective (minimize refusals, minimize KL), 100 trials, seed 42, silhouette-guided position bounds.

Usage

transformers

from transformers import pipeline

pipe = pipeline(
    "text-generation",
    model="anlord/gemma-4-E2B-it-abliterated",
    torch_dtype="bfloat16",
    device_map="auto",
)

messages = [{"role": "user", "content": "Write a short story about a robot."}]
out = pipe(messages, max_new_tokens=256)
print(out[0]["generated_text"][-1]["content"])

Thinking mode

The it checkpoint emits [Start thinking] … [end thinking] reasoning blocks by default. The bundled chat template supports disabling them:

prompt = pipe.tokenizer.apply_chat_template(
    messages, tokenize=False, add_generation_prompt=True, enable_thinking=False
)

llama.cpp / GGUF

Ready-made quants from F16 down to Q4_0 live in the companion repo: anlord/gemma-4-E2B-it-abliterated-GGUF. Note: the GGUFs contain the text tower only (vision/audio are not used by llama.cpp for text generation).

Pareto front & milder variants

The optimization produced a 4-point Pareto front. This repo ships the automatic pick (trial 16 — minimum refusals). If you prefer a smaller distribution shift, re-run with one of these fixed parameter sets:

Each trial's exact parameters are in pareto_trials/, and every variant can be reproduced with the bundled study journal (see below).

How it was made

Datasets

A response counts as a refusal if it matches any of ~30 keyword markers (sorry, I cannot, as an AI, illegal, …) — the classic abliteration benchmark protocol.

Repository contents

├── config.json · generation_config.json · processor_config.json
├── chat_template.jinja · tokenizer.json · tokenizer_config.json
├── model-00001..3-of-00003.safetensors · model.safetensors.index.json
├── abliteration_reproduction.json      # exact best-trial parameters + weight hashes
├── abliteration_pareto_front.json      # front points & metrics
├── native_abliteration_metrics.json    # before/after scores
├── pareto_trials/                      # fixed params for trials 10/16/60/66
└── reproduce/                          # full reproduction bundle
    ├── reproduce.json                  # everything needed to re-run the winning trial
    ├── config.json · requirements.txt
    ├── google--gemma-4-E2B-it.jsonl    # complete Optuna study journal (100 trials)
    ├── SHA256SUMS                      # weight hashes to verify your download
    └── README.md                       # step-by-step reproduction guide

Reproduction

The run is fully deterministic (seed 42, pinned datasets by revision, journal kept).

1. Verify weights after download:

   sha256sum -c SHA256SUMS   # from the reproduce/ folder, run it in the model root
   

2. Install the pinned environment from reproduce/requirements.txt (Python 3.13, torch 2.11.0+cu130, transformers 5.19.0).

3. Either re-run the whole 100-trial search or replay only the winning trial — both are driven by reproduce/reproduce.json; see reproduce/README.md for the exact commands.

Limitations & intended use

• This model will answer harmful requests. It is released for research on alignment, interpretability and refusal-direction analysis. You are responsible for how you use it and for complying with the laws of your jurisdiction and the base model license.
• Refusal behavior is heavily reduced but not zero (4/100 prompts still matched refusal markers).
• The KL shift means outputs may differ from the base model beyond refusals alone; benchmark before production use.
• Abliteration does not make a model "safe" or "unsafe" — it removes one specific behavioral direction. Other alignment properties remain unchanged.

License

This model inherits the base model license: Gemma (see google/gemma-4-E2B-it). The pipeline tooling (Anlord Abliterator) is AGPL-3.0.

Credits

• google/gemma-4-E2B-it — base model
• mlabonne/harmless_alpaca & mlabonne/harmful_behaviors — evaluation datasets
• Anlord Abliterator — native abliteration & optimization engine used for this run