diff --git a/agent/agent_init.py b/agent/agent_init.py
index 155ddba578..da92e6f881 100644
--- a/agent/agent_init.py
+++ b/agent/agent_init.py
@@ -2961,6 +2961,7 @@ def init_agent(
         "client_kwargs": dict(agent._client_kwargs),
         "use_prompt_caching": agent._use_prompt_caching,
         "use_native_cache_layout": agent._use_native_cache_layout,
+        "reasoning_echo_flag": getattr(agent, "_reasoning_echo_flag", False),
         # Context engine state that _try_activate_fallback() overwrites.
         # Use getattr for model/base_url/api_key/provider since plugin
         # engines may not have these (they're ContextCompressor-specific).
diff --git a/agent/agent_runtime_helpers.py b/agent/agent_runtime_helpers.py
index 451b3a0927..bcb1cc3a04 100644
--- a/agent/agent_runtime_helpers.py
+++ b/agent/agent_runtime_helpers.py
@@ -2654,6 +2654,7 @@ def switch_model(agent, new_model, new_provider, api_key='', base_url='', api_mo
             "_anthropic_base_url",
             "_is_anthropic_oauth",
             "_config_context_length",
+            "_reasoning_echo_flag",
         )
     }
     # _client_kwargs is a dict — snapshot a shallow copy so mutating the