fix(guardrails): censor user and model events when blocked

src/va_agent/governance.py

@@ -233,5 +233,9 @@ class GovernancePlugin:
                         deleted,
                     )
 
+            # Reset censorship flag for next interaction
+            if callback_context:
+                callback_context.state["guardrail_censored"] = False
+
         except Exception:
             logger.exception("Error in after_model_callback")

src/va_agent/session.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+import copy
 import logging
 import time
 import uuid
@@ -378,8 +379,55 @@ class FirestoreSessionService(BaseSessionService):
         event = await super().append_event(session=session, event=event)
         session.last_update_time = event.timestamp
 
+        # Determine if we need to censor this event (model response when guardrail blocked)
+        should_censor_model = (
+            session.state.get("guardrail_blocked", False)
+            and event.author == app_name
+            and hasattr(event, "content")
+            and event.content
+            and event.content.parts
+            and not session.state.get("guardrail_censored", False)
+        )
+
+        # Prepare event data for Firestore
+        if should_censor_model:
+            # Mark as censored to avoid double-censoring
+            session.state["guardrail_censored"] = True
+
+            # Create a censored version of the model response
+            event_to_save = copy.deepcopy(event)
+            event_to_save.content.parts[0].text = "[respuesta de adversidad]"
+            event_data = event_to_save.model_dump(mode="json", exclude_none=True)
+
+            # Also censor the previous user message in Firestore
+            # Find the last user event in the session
+            for i in range(len(session.events) - 1, -1, -1):
+                prev_event = session.events[i]
+                if (
+                    prev_event.author == "user"
+                    and prev_event.content
+                    and prev_event.content.parts
+                ):
+                    # Update this event in Firestore with censored content
+                    censored_user_content = Content(
+                        role="user", parts=[Part(text="[pregunta mala]")]
+                    )
+                    await (
+                        self._events_col(app_name, user_id, session_id)
+                        .document(prev_event.id)
+                        .update(
+                            {
+                                "content": censored_user_content.model_dump(
+                                    mode="json", exclude_none=True
+                                )
+                            }
+                        )
+                    )
+                    break
+        else:
+            event_data = event.model_dump(mode="json", exclude_none=True)
+
         # Persist event document
-        event_data = event.model_dump(mode="json", exclude_none=True)
         await (
             self._events_col(app_name, user_id, session_id)
             .document(event.id)