RavenGuard-Gen — Multilingual Safety Guard for LLM Agents

RavenGuard-Gen is a compact, multilingual safety guard for LLM agents. Multilingual support is a first-class design goal rather than an English model plus translated safety examples: the tokenizer, pretraining mixture, backbone, safety taxonomy, and evaluation protocol were built to handle different scripts and language families from the start.

RavenGuard is built on Netis Amniota, a decoder language model trained from random initialisation by Netis rather than fine-tuned from a Qwen, Llama, or other existing backbone. Its 65,536-entry tokenizer and NetisMix multilingual data recipe were developed together with the model. Pretraining and mid-training processed more than 13.6B tokens; safety post-training processed approximately 4.5B tokens, for more than 18B training tokens in total. This count is the cumulative number of tokens presented to the model, including repeated post-training passes, not the size of a deduplicated source corpus.

The model officially covers 18 languages: English, Chinese, Hindi, Spanish, Arabic, Bengali, Portuguese, Russian, Japanese, German, French, Korean, Italian, Vietnamese, Thai, Indonesian, Swahili, and Javanese. This includes right-to-left Arabic, non-segmented Thai, CJK scripts, Indic scripts, and broad Southeast Asian coverage. The model is compact (≈0.8B) and is designed as a low-latency trust layer in front of enterprise LLM agents.

RavenGuard-Gen is a generative whole-input / whole-output guard. It reads a prompt or a full response and, in a short greedy decode, emits a structured label block (Decision / Risk / Severity / Categories / Refusal); the binary verdict is the Severity line, and a reference soft score is the calibrated softmax at the Severity token (see Usage below). Use it as a prompt filter or an end-of-response check.

A companion streaming guard, RavenGuard-Stream — a per-token 3-way classification head on the same Netis Amniota backbone that flags harmful content while it is being generated — is released separately in its own repository. This card covers RavenGuard-Gen only.

Repository: netis-ai/RavenGuard-gen.

Multilingual design and coverage

Multilingual guardrails are not solved by translating an English policy dataset. Languages differ in writing direction, word-boundary conventions, morphology, tokenisation length, regional usage, and the way harmful intent is expressed indirectly. These differences are especially consequential for a 0.8B model: inefficient tokenisation consumes context and model capacity before the safety decision is even made.

RavenGuard addresses this at three levels:

1. Tokenizer and backbone: the 65,536-entry tokenizer was trained for multilingual use and is native to Netis Amniota; the released RavenGuard-Gen configuration uses 20 decoder layers, a 1,280 hidden dimension, 10 attention heads, and a 2,048-token context window.
2. Training recipe: NetisMix introduces multilingual data during pretraining instead of adding target languages only at the final safety-tuning stage. Safety post-training then uses a shared severity and risk-category grammar across languages.
3. Evaluation and calibration: ChineseSafe measures Chinese safety directly; PolyGuard compares all guards on the same 2,039 examples across 17 languages. Production thresholds should still be calibrated per language and domain, on the deployment's own traffic.

The 18-language list above is the model's declared training coverage. PolyGuard's 17-language set is a benchmark-specific evaluation slice and is not the product language list.

Cross-model comparison

All comparisons below are computed on shared public benchmarks over identical sample sets with identical gold labels and a common decision rule.

Chinese safety — ChineseSafe (same 500-sample set, all models)

¹ Qwen3Guard-Gen emits a categorical verdict with no probability, so a threshold-free AUROC is not defined for it; every model that does emit a score is scored below.

² RavenGuard's AUROC is a reference metric: the calibrated softmax read at the generated Severity token (the same score guardbench and reproduce_eval.py emit). Baseline AUROCs are each model's own continuous score. Treat AUROC as a rough separability indicator, not the headline — the usable comparison is F1/recall at a calibrated operating point.

RavenGuard-Gen leads every evaluated guard on Chinese F1 (by ≥16 points) at roughly one-tenth the parameter count. Precision is uniformly high across guards; the gap is almost entirely recall: the 8–9B guards catch only 25–56% of Chinese harm, RavenGuard 78.6%.

General multilingual — PolyGuard response (same 2,039-sample set, 17 languages)

¹ Qwen3Guard-Gen emits categorical verdicts (no probability → AUROC undefined). ² RavenGuard AUROC is the calibrated Severity-token read (reference only, see footnote ² above); baseline AUROCs are each model's own continuous score.

On usable F1/recall, RavenGuard-Gen (0.8B) sits with the Qwen generative guards at the top (F1 83.1, recall 77.1) and far above the 8–9B guards, which catch only 32–59% of harm. On threshold-free AUROC RavenGuard (87.0) reads a few points below the 8B guards (Granite 92.1, Llama 93.3) — its edge is not raw separability but the recall-first operating point: the 8B guards buy their low FPR (1–3%) by sitting at conservative operating points that discard most of that recall, while RavenGuard's higher FPR here (8.5) is the flip side of keeping recall high — the subject of the next section.

RavenGuard on the full heldout (n=6,800)

³ AUROC and R@1%FPR here are the calibrated Severity-token figures — the same score source as every other table in this card, and what guardbench reproduces. Treat them as reference separability indicators; F1/Recall/FPR (read from the Severity line) are the usable operating-point metrics.

FPR here (10.5%) is on PolyGuard's own benign responses, which include dual-use and borderline content; it reflects the recall-tuned operating point rather than any particular deployment's traffic. The p50 latency is the generative moderation call on an H200.

Over-refusal: real traffic vs. adversarial benchmarks

"False-positive rate" depends entirely on how benign the benign set is:

• OR-Bench-Toxic (prompts that read as toxic but are benign): 0.0% over-block.
• XSTest (crafted over-refusal probes): 5.6% over-block.
• PolyGuard heldout benign (includes dual-use and borderline responses): a 6–16% per-language band.

The spread is deliberate: RavenGuard-Gen is tuned for harm recall, which raises false-positives on adversarial benchmark-benign. How that operating point behaves on a given deployment's traffic depends on that traffic — measure it before rollout, and calibrate the per-language threshold to your own false-positive budget.

Why RavenGuard does not chase the PolyGuard score

The PolyGuard table above rewards a specific behaviour: label its "benign" responses as safe. But a large share of those responses are dual-use — a fluent, detailed answer to a harmful-adjacent question (how a certain toxin acts on the body; how an exploit class works; how a scam is structured) that the dataset marks benign because it reads educational. A guard optimised to score well there learns to let that content through.

That is a policy choice disguised as a metric. Consider a concrete case: a detailed, competent explanation of how to synthesise a controlled substance, framed as "for a chemistry class." PolyGuard's benign label says allow it; a strict enterprise guard says flag it. Counting the flag as a false-positive doesn't make the guard wrong — it makes the benchmark's boundary more permissive than the deployment's.

You can see the cost of chasing the score in the same tables. The 8–9B guards post the lowest PolyGuard FPR (1–3%) — and the lowest real recall: 25–56% on ChineseSafe, 32–59% on PolyGuard. Their low false-positive rate is bought by being lenient on exactly the ambiguous content that matters. RavenGuard's higher benchmark-FPR is not a capability gap but a deliberate operating-point choice: it accepts a higher benchmark-FPR to keep recall high, where the 8B guards sit conservative and discard recall. The choice of operating point is the product. What that choice costs on real traffic is a property of the traffic, and is left to the deployment to measure — see release/REPRODUCE.md for the harness and docs/prodsim-v2-results.md for a worked measurement on public real-traffic data.

Usage

RavenGuard-Gen ships as a self-contained trust_remote_code model (the custom backbone is bundled in the repo). Weights are byte-faithful to the trained checkpoint. The guard reads a prompt (or a prompt + response) under the policy prompt below and, in a short greedy decode, emits a fixed label block:

Decision: <allow|block|rewrite|ask_clarification|require_approval|human_review>
Risk: <comma-separated risk names, or none>
Severity: <Safe|Controversial|Unsafe>
Categories: <comma-separated S-codes, or None>
Refusal: <Yes|No>

The binary safe/unsafe verdict is the generated Severity line — this is the deployment decision. For a soft score (AUROC / threshold tuning) read the calibrated softmax at the generated Severity token: P(Unsafe ∪ Controversial) vs P(Safe). Treat this as a calibrated-severity read for reference, not a free-threshold ranking score.

import os
os.environ.setdefault("NETIS_AMNIOTA_ATTN_BACKEND", "sdpa")  # see "Runtime notes" below
from transformers import AutoModelForCausalLM

model = AutoModelForCausalLM.from_pretrained(
    "netis-ai/RavenGuard-gen", trust_remote_code=True,
    torch_dtype="float32").cuda().eval()

For the complete, self-contained inference recipe — the exact policy prompt, the greedy decode, the label parse, and the Severity-token calibrated score — see reproduce_eval.py in this repo (Guard.classify). It runs the model end to end with no guardbench install and no network.

Runtime notes (please read before running)

• Attention backend: set NETIS_AMNIOTA_ATTN_BACKEND=sdpa. The default FlashAttention-4 (CuTeDSL) path raises a window_size_left error on GPUs that support only FlashAttention-2 (e.g. consumer Blackwell / RTX 5090, sm_120). SDPA is portable and numerically identical.
• Batch size 1 only, for now. The bundled forward does not yet consume attention_mask, so a left-padded batch would be scored incorrectly and silently. Moderate one sequence at a time until the batched (attention_mask / KV-cache / generate) path is released.
• Runtime dependencies beyond transformers: torch, tiktoken, rustbpe, filelock.

Intended use

RavenGuard-Gen performs input and output moderation: run it as a prompt filter before the main model, as an end-of-response check before a reply reaches the user, or both. It suits multilingual input/output moderation and end-of-turn checks, including Chinese-, Arabic-, Spanish-, Portuguese-, Hindi-, and Thai-heavy workloads. For latency-sensitive streaming deployments where harmful content must be interrupted mid-generation, pair it with the companion RavenGuard-Stream model (released separately).

Operating notes

• RavenGuard is a probabilistic classifier. Operating thresholds are calibrated per language and should be re-calibrated to the target false-positive budget of each deployment.
• Validate tokenisation, recall, and false-positive rates on the deployment's own language varieties, code-switching patterns, and regional vocabulary. Declared language support does not remove the need for domain-specific calibration and monitoring.
• Cross-model figures in this card are computed on shared public benchmarks (ChineseSafe n=500, PolyGuard response n=2,039) with identical sample sets and gold labels.

Evaluation methodology

All figures come from a reproducible harness (guardbench) with an EVAL_ONLY firewall between training and test corpora, per-language threshold calibration, and threshold-free capability metrics (AUROC, Recall@FPR). Cross-model comparisons are computed on identical id sets with identical gold labels. See docs/ravenguard-technical-report.md for the full protocol.

Citation

@misc{ravenguard2026,
  title  = {RavenGuard: Multilingual Safety Guards for LLM Agents},
  author = {netis},
  year   = {2026},
  url    = {https://huggingface.co/netis-ai/RavenGuard-gen}
}