add semantic guard registration

litellm/proxy/guardrails/guardrail_hooks/semantic_guard/__init__.py

@@ -0,0 +1,76 @@
+"""
+Semantic Guard guardrail — embedding-based prompt injection detection.
+
+Uses semantic-router to match user prompts against known attack patterns.
+"""
+
+from typing import TYPE_CHECKING, Optional
+
+import litellm
+from litellm.constants import (
+    DEFAULT_SEMANTIC_GUARD_EMBEDDING_MODEL,
+    DEFAULT_SEMANTIC_GUARD_SIMILARITY_THRESHOLD,
+)
+from litellm.proxy.guardrails.guardrail_hooks.semantic_guard.semantic_guard import (
+    SemanticGuardrail,
+)
+from litellm.types.guardrails import SupportedGuardrailIntegrations
+
+if TYPE_CHECKING:
+    from litellm import Router
+    from litellm.types.guardrails import Guardrail, LitellmParams
+
+
+def initialize_guardrail(
+    litellm_params: "LitellmParams",
+    guardrail: "Guardrail",
+    llm_router: Optional["Router"] = None,
+):
+    """
+    Initialize the Semantic Guard guardrail.
+
+    Args:
+        litellm_params: Guardrail configuration parameters
+        guardrail: Guardrail metadata
+        llm_router: LiteLLM Router instance (required for embeddings)
+
+    Returns:
+        Initialized SemanticGuardrail instance
+    """
+    guardrail_name = guardrail.get("guardrail_name")
+    if not guardrail_name:
+        raise ValueError("SemanticGuard: guardrail_name is required")
+
+    if llm_router is None:
+        raise ValueError(
+            "SemanticGuard requires llm_router for embeddings. "
+            "Configure a model_list with an embedding model."
+        )
+
+    semantic_guardrail = SemanticGuardrail(
+        guardrail_name=guardrail_name,
+        llm_router=llm_router,
+        embedding_model=getattr(litellm_params, "embedding_model", None)
+        or DEFAULT_SEMANTIC_GUARD_EMBEDDING_MODEL,
+        similarity_threshold=getattr(litellm_params, "similarity_threshold", None)
+        or DEFAULT_SEMANTIC_GUARD_SIMILARITY_THRESHOLD,
+        route_templates=getattr(litellm_params, "route_templates", None),
+        custom_routes_file=getattr(litellm_params, "custom_routes_file", None),
+        custom_routes=getattr(litellm_params, "custom_routes", None),
+        on_flagged_action=getattr(litellm_params, "on_flagged_action", "block"),
+        event_hook=litellm_params.mode,  # type: ignore
+        default_on=litellm_params.default_on or False,
+    )
+
+    litellm.logging_callback_manager.add_litellm_callback(semantic_guardrail)
+
+    return semantic_guardrail
+
+
+guardrail_initializer_registry = {
+    SupportedGuardrailIntegrations.SEMANTIC_GUARD.value: initialize_guardrail,
+}
+
+guardrail_class_registry = {
+    SupportedGuardrailIntegrations.SEMANTIC_GUARD.value: SemanticGuardrail,
+}