Shieldstral's core innovation lies in redefining content moderation as a binary question-answering task. Each request contains three parts: <Instruct> provides evaluation context and strictness, <Query> is a clear yes/no question (e.g., "Does the content promote physical violence?"), and <Document> is the content to be moderated, which can be a prompt, a response, a prompt-response pair, or an image with optional text.
At inference, the model reads only the logits for yes and no, and normalizes them via softmax into a continuous safety score. This design unifies prompt classification, response moderation, refusal detection, and toxicity detection, making the policy entirely present in the prompt, so a single checkpoint can adapt to new policies at deployment time without retraining.