feat(guardrails): add Compresr guardrail for query-aware context compression

litellm/llms/openai/responses/guardrail_translation/handler.py

@@ -247,6 +247,8 @@ def _merge_tools_after_guardrail(
         """
         Merge remapped guardrailed tools with original tools that were not sent
         to the guardrail (e.g. web_search, web_search_preview), preserving order.
+        Tools a guardrail appended (``remapped`` longer than ``original_tools``)
+        have no original slot and are kept so an injected tool is not dropped.
         """
         if not original_tools:
             return remapped
@@ -262,6 +264,8 @@ def _merge_tools_after_guardrail(
                 if j < len(remapped):
                     result.append(remapped[j])
                     j += 1
+        # Keep guardrail-appended tools that matched no original slot above.
+        result.extend(remapped[j:])
         return result
 
     def _apply_guardrailed_tools_to_data(

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

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from litellm.types.guardrails import (
+    GuardrailEventHooks,
+    Mode,
+    SupportedGuardrailIntegrations,
+)
+
+from .compresr import CompresrGuardrail
+
+if TYPE_CHECKING:
+    from litellm.types.guardrails import Guardrail, LitellmParams
+
+
+def _coerce_event_hook(
+    mode: str | list[str] | Mode,
+) -> GuardrailEventHooks | list[GuardrailEventHooks] | Mode:
+    if isinstance(mode, Mode):
+        return mode
+    if isinstance(mode, list):
+        return [GuardrailEventHooks(item) for item in mode]
+    return GuardrailEventHooks(mode)
+
+
+def _get_optional_value(litellm_params: LitellmParams, optional_params: object | None, attribute_name: str) -> object:
+    if optional_params is not None:
+        value = getattr(optional_params, attribute_name, None)
+        if value is not None:
+            return value
+    return getattr(litellm_params, attribute_name, None)
+
+
+def initialize_guardrail(litellm_params: LitellmParams, guardrail: Guardrail) -> CompresrGuardrail:
+    import litellm
+
+    optional_params = getattr(litellm_params, "optional_params", None)
+
+    _callback = CompresrGuardrail(
+        api_base=litellm_params.api_base,
+        api_key=litellm_params.api_key,
+        model=litellm_params.model,
+        target_compression_ratio=_get_optional_value(litellm_params, optional_params, "target_compression_ratio"),
+        coarse=_get_optional_value(litellm_params, optional_params, "coarse"),
+        min_chars_to_compress=_get_optional_value(litellm_params, optional_params, "min_chars_to_compress"),
+        compress_tool_outputs=_get_optional_value(litellm_params, optional_params, "compress_tool_outputs"),
+        compress_system=_get_optional_value(litellm_params, optional_params, "compress_system"),
+        compress_history=_get_optional_value(litellm_params, optional_params, "compress_history"),
+        compress_last_user=_get_optional_value(litellm_params, optional_params, "compress_last_user"),
+        enable_retrieval=_get_optional_value(litellm_params, optional_params, "enable_retrieval"),
+        max_bytes_per_call=_get_optional_value(litellm_params, optional_params, "max_bytes_per_call"),
+        allow_bypass_header=_get_optional_value(litellm_params, optional_params, "allow_bypass_header"),
+        dynamic=_get_optional_value(litellm_params, optional_params, "dynamic"),
+        dynamic_min_ratio=_get_optional_value(litellm_params, optional_params, "dynamic_min_ratio"),
+        dynamic_max_ratio=_get_optional_value(litellm_params, optional_params, "dynamic_max_ratio"),
+        compression_params=_get_optional_value(litellm_params, optional_params, "compression_params"),
+        guardrail_name=guardrail["guardrail_name"],
+        event_hook=_coerce_event_hook(litellm_params.mode),
+        default_on=litellm_params.default_on or False,
+        unreachable_fallback=litellm_params.unreachable_fallback,
+    )
+    litellm.logging_callback_manager.add_litellm_callback(  # pyright: ignore[reportUnknownMemberType]  # callback manager is untyped
+        _callback
+    )
+    return _callback
+
+
+guardrail_initializer_registry = {
+    SupportedGuardrailIntegrations.COMPRESR.value: initialize_guardrail,
+}
+
+guardrail_class_registry = {
+    SupportedGuardrailIntegrations.COMPRESR.value: CompresrGuardrail,
+}