diff --git a/agent/conversation_loop.py b/agent/conversation_loop.py
index 2d01ae9a85..438adf6647 100644
--- a/agent/conversation_loop.py
+++ b/agent/conversation_loop.py
@@ -7660,8 +7660,18 @@ def run_conversation(
                     # these add 20-30K tokens the messages-only
                     # estimate misses, which can skip compression
                     # past the configured threshold (#14695).
-                    _real_tokens = estimate_request_tokens_rough(
-                        messages, tools=agent.tools or None
+                    # Route-aware (#96995/#97602 class): on a compacted
+                    # native-Codex session the generic durable-history
+                    # figure overstates the wire and would false-trigger
+                    # compression here exactly like the pre-API guard —
+                    # this fallback runs precisely when no provider usage
+                    # is available (post-disconnect / gateway restart),
+                    # the unanchored case from #97602's repro.
+                    _real_tokens = _midturn_request_pressure_tokens(
+                        agent,
+                        messages,
+                        active_system_prompt or "",
+                        estimate_messages_tokens_rough(messages),
                     )
 
                 if (
diff --git a/agent/turn_context.py b/agent/turn_context.py
index 01dbf27371..8959386bd4 100644
--- a/agent/turn_context.py
+++ b/agent/turn_context.py
@@ -883,10 +883,15 @@ def build_turn_context(
         _idle_gap = time.time() - getattr(agent, "_last_activity_ts", time.time())
         if _idle_gap >= _idle_after:
             _compressor = agent.context_compressor
-            _idle_tokens = estimate_request_tokens_rough(
+            # Route-aware pressure (#96995/#97602 class): on a compacted
+            # native-Codex session the generic durable-history figure
+            # overstates the wire by orders of magnitude and would fire an
+            # idle compaction the next request never needed. Reuse the
+            # preflight estimator (anchor → native pruned → generic).
+            _idle_tokens = _preflight_request_tokens(
+                agent,
                 messages,
-                system_prompt=active_system_prompt or "",
-                tools=agent.tools or None,
+                active_system_prompt or "",
             )
             # Post-compression target size: don't summarise a thread already
             # below what compaction would reduce it to.
@@ -1297,10 +1302,16 @@ def build_turn_context(
                 if callable(_clear_warn):
                     _clear_warn()
             else:
-                _uncompressed_tokens = estimate_request_tokens_rough(
+                # Route-aware (#96995/#97602 class): the warn site in the
+                # conversation loop now measures the checkpoint-pruned wire
+                # payload on native-Codex sessions, so the re-arm must use
+                # the same figure — otherwise a compacted session that fits
+                # on the wire never clears the dedup and future genuine
+                # overflow warnings stay suppressed.
+                _uncompressed_tokens = _preflight_request_tokens(
+                    agent,
                     messages,
-                    system_prompt=active_system_prompt or "",
-                    tools=agent.tools or None,
+                    active_system_prompt or "",
                 )
                 if _uncompressed_tokens <= _ctx_len:
                     _clear_warn = getattr(