diff --git a/atlasbot/api/http.py b/atlasbot/api/http.py
index c164db1..49de446 100644
--- a/atlasbot/api/http.py
+++ b/atlasbot/api/http.py
@@ -21,6 +21,7 @@ class AnswerRequest(BaseModel):
     mode: str | None = None
     history: list[dict[str, str]] | None = None
     conversation_id: str | None = None
+    snapshot_pin: bool | None = None
 
 
 class AnswerResponse(BaseModel):
@@ -31,7 +32,7 @@ class Api:
     def __init__(
         self,
         settings: Settings,
-        answer_handler: Callable[[str, str, list[dict[str, str]] | None, str | None], Awaitable[AnswerResult]],
+        answer_handler: Callable[[str, str, list[dict[str, str]] | None, str | None, bool | None], Awaitable[AnswerResult]],
     ) -> None:
         self._settings = settings
         self._answer_handler = answer_handler
@@ -55,7 +56,7 @@ class Api:
                 raise HTTPException(status_code=400, detail="missing question")
             mode = (payload.mode or "quick").strip().lower()
             conversation_id = payload.conversation_id
-            result = await self._answer_handler(question, mode, payload.history, conversation_id)
+            result = await self._answer_handler(question, mode, payload.history, conversation_id, payload.snapshot_pin)
             log.info(
                 "answer",
                 extra={
diff --git a/atlasbot/engine/answerer.py b/atlasbot/engine/answerer.py
index 3fecd82..8062aa2 100644
--- a/atlasbot/engine/answerer.py
+++ b/atlasbot/engine/answerer.py
@@ -97,6 +97,7 @@ class AnswerEngine:
         history: list[dict[str, str]] | None = None,
         observer: Callable[[str, str], None] | None = None,
         conversation_id: str | None = None,
+        snapshot_pin: bool | None = None,
     ) -> AnswerResult:
         question = (question or "").strip()
         if not question:
@@ -148,9 +149,10 @@ class AnswerEngine:
             return response
 
         state = self._get_state(conversation_id)
+        pin_snapshot = bool(snapshot_pin) or self._settings.snapshot_pin_enabled
         snapshot = self._snapshot.get()
         snapshot_used = snapshot
-        if self._settings.snapshot_pin_enabled and state and state.snapshot:
+        if pin_snapshot and state and state.snapshot:
             snapshot_used = state.snapshot
         summary = build_summary(snapshot_used)
         allowed_nodes = _allowed_nodes(summary)
@@ -488,6 +490,11 @@ class AnswerEngine:
                     model=plan.model,
                     tag="evidence_fix",
                 )
+                if unknown_nodes or unknown_namespaces:
+                    refreshed_nodes = _find_unknown_nodes(reply, allowed_nodes)
+                    refreshed_namespaces = _find_unknown_namespaces(reply, allowed_namespaces)
+                    if refreshed_nodes or refreshed_namespaces:
+                        reply = _strip_unknown_entities(reply, refreshed_nodes, refreshed_namespaces)
                 if runbook_paths and resolved_runbook and _needs_runbook_reference(normalized, runbook_paths, reply):
                     if observer:
                         observer("runbook_enforce", "enforcing runbook path")
@@ -856,7 +863,7 @@ class AnswerEngine:
             )
 
         if conversation_id and claims:
-            self._store_state(conversation_id, claims, summary, snapshot_used)
+            self._store_state(conversation_id, claims, summary, snapshot_used, pin_snapshot)
 
         meta = _build_meta(mode, call_count, call_cap, limit_hit, classify, tool_hint, started)
         return AnswerResult(reply, scores, meta)
@@ -1086,9 +1093,10 @@ class AnswerEngine:
         claims: list[ClaimItem],
         summary: dict[str, Any],
         snapshot: dict[str, Any] | None,
+        pin_snapshot: bool,
     ) -> None:
         snapshot_id = _snapshot_id(summary)
-        pinned_snapshot = snapshot if self._settings.snapshot_pin_enabled else None
+        pinned_snapshot = snapshot if pin_snapshot else None
         payload = {
             "updated_at": time.monotonic(),
             "claims": _claims_to_payload(claims),
diff --git a/atlasbot/main.py b/atlasbot/main.py
index 9316356..c05961e 100644
--- a/atlasbot/main.py
+++ b/atlasbot/main.py
@@ -32,23 +32,47 @@ async def main() -> None:
     async def handler(payload: dict[str, object]) -> dict[str, object]:
         history = payload.get("history") if isinstance(payload, dict) else None
         conversation_id = payload.get("conversation_id") if isinstance(payload, dict) else None
+        snapshot_pin = payload.get("snapshot_pin") if isinstance(payload, dict) else None
         result = await engine.answer(
             str(payload.get("question", "") or ""),
             mode=str(payload.get("mode", "quick") or "quick"),
             history=history if isinstance(history, list) else None,
             conversation_id=str(conversation_id) if isinstance(conversation_id, str) else None,
+            snapshot_pin=bool(snapshot_pin) if isinstance(snapshot_pin, bool) else None,
         )
         return {"reply": result.reply, "scores": result.scores.__dict__}
 
     queue = QueueManager(settings, handler)
     await queue.start()
 
-    async def answer_handler(question: str, mode: str, history=None, conversation_id=None, observer=None) -> AnswerResult:
+    async def answer_handler(
+        question: str,
+        mode: str,
+        history=None,
+        conversation_id=None,
+        snapshot_pin: bool | None = None,
+        observer=None,
+    ) -> AnswerResult:
         if settings.queue_enabled:
-            payload = await queue.submit({"question": question, "mode": mode, "history": history or [], "conversation_id": conversation_id})
+            payload = await queue.submit(
+                {
+                    "question": question,
+                    "mode": mode,
+                    "history": history or [],
+                    "conversation_id": conversation_id,
+                    "snapshot_pin": snapshot_pin,
+                }
+            )
             reply = payload.get("reply", "") if isinstance(payload, dict) else ""
             return AnswerResult(reply=reply or "", scores=result_scores(payload), meta={"mode": mode})
-        return await engine.answer(question, mode=mode, history=history, observer=observer, conversation_id=conversation_id)
+        return await engine.answer(
+            question,
+            mode=mode,
+            history=history,
+            observer=observer,
+            conversation_id=conversation_id,
+            snapshot_pin=snapshot_pin,
+        )
 
     api = Api(settings, answer_handler)
     server = uvicorn.Server(uvicorn.Config(api.app, host="0.0.0.0", port=settings.http_port, log_level="info"))