GLM-5.3-Flash Uncensored β Prefill Top-up (steering vectors)
Zero-refusal GLM-5.3-Flash as ~180 KB: two refusal-direction vectors + a runtime loader. No weights are included or modified β this is a prefill-only activation top-up for OrcaRouter's GLM-5.3-Flash-Uncensored abliteration.
Why it's this small
The winning refusal-suppression technique is prefill-only constant injection: add dose Γ rΜ to the inter-layer hidden state after layers 25/26, during prompt processing only. A weight edit cannot express "prefill only" β weight edits fire on every forward pass, including every decode step, and that decode-time injection is exactly what destroys long-generation quality in classic constant-steering abliterations. So the intervention is inherently a runtime one, and the release is inherently tiny: the model you need is OrcaRouter's, unchanged.
Results
Served eval: 20 held-out harmful prompts + 10 capability prompts, greedy decoding, 1000-token generations, low reasoning effort:
| configuration | refusal | capability |
|---|---|---|
| dealign CRACK (community) | 25% | 10/10 |
| OrcaRouter abliteration alone | 10% | 10/10 |
| OrcaRouter + this top-up (dose β8) | 0% true* | 10/10 |
* The classifier reads 5%, but the single hit is a false positive β the model says "I can't produce an actual video file" (a text model being honest) and then produces the full script.
Usage
pip install -e git+https://github.com/Libertai/prefill-steering.git
Bake the injection into your vLLM glm5next/nvidia/model.py (details in the repo README):
python3 bake_injection.py \
--model /path/to/vllm/models/glm5next/nvidia/model.py \
--subspace vectors/glm53_flash_orca_rhat_L25_L26.json \
--mode const_po --dose -8 --layers 25,26
GLM53_REFUSAL_INJECT=1 <vllm serve the OrcaRouter NVFP4 checkpoint>
Runtime hooks (prefill_steer.py) and the full reproduction harness (direction capture β steering sweep β served eval) are in the GitHub repo.
Files
vectors/glm53_flash_orca_rhat_L25_L26.jsonβ unit refusal directions at layers 25/26, captured from the OrcaRouter abliterationprefill_steer.pyβ runtime forward-hook implementation (reference mechanism)bake_injection.pyβ patches the injection into the vLLM model file, gated byGLM53_REFUSAL_INJECT
Findings behind this release
- Projection ablation β the canonical abliteration operator β fails on this model (8 variants, 90β100% refusal retained). Only constant displacement along the refusal direction works.
- Magnitude removes refusal; direction preserves capability β a random vector at the same dose suppresses refusal and collapses capability (0/10).
- Only the inter-layer hidden state is injectable β the 4-stream mHC architecture (
hidden_states, residual, post, comb) is destroyed by injection into any other stream. - Decode-time injection is the quality killer β prefill-only gating preserves suppression and restores creativity.
- Abliteration stages compose β the residual direction of an abliterated model is cheaper to suppress than the original's (roughly half the dose here).
Full writeup: LibertAI Labs β story β’ LibertAI Labs β paper β’ GitHub: Libertai/prefill-steering
Credits
Built on OrcaRouter's community abliteration (weights unchanged), the single-direction account of refusal from Arditi et al. (arXiv:2406.11732), prompt-only steering vectors from Bao et al. (arXiv:2605.05983), and the open abliteration community. The entire study β direction capture, falsification sweeps, weight surgery, serving, evaluation β was run by an autonomous agent session.
Caveats
20 harmful prompts, 10 capability prompts, single seed, greedy decoding, marker-classifier scoring. "0% refusal" is a measurement on a thin distribution sample, not a certificate. The vectors are specific to the OrcaRouter abliteration at NVFP4 precision; re-capture for other checkpoints (the harness does this in one command).