diff --git a/rdagent/core/utils.py b/rdagent/core/utils.py
index dd6b8e751..ab61b68e9 100644
--- a/rdagent/core/utils.py
+++ b/rdagent/core/utils.py
@@ -56,6 +56,14 @@ def __reduce__(self) -> NoReturn:
 
 
 def parse_json(response: str) -> Any:
+    import re
+
+    # Some LLM providers (e.g. Volcengine) return Python-style booleans
+    # (True/False) instead of JSON-standard (true/false). Normalize them
+    # before parsing to avoid JSONDecodeError.
+    response = re.sub(r"\bTrue\b", "true", response)
+    response = re.sub(r"\bFalse\b", "false", response)
+    response = re.sub(r"\bNone\b", "null", response)
     try:
         return json.loads(response)
     except json.decoder.JSONDecodeError:
diff --git a/rdagent/log/ui/app.py b/rdagent/log/ui/app.py
index 881b32fb6..fe4c2fa1a 100644
--- a/rdagent/log/ui/app.py
+++ b/rdagent/log/ui/app.py
@@ -229,6 +229,9 @@ def get_msgs_until(end_func: Callable[[Message], bool] = lambda _: True):
                         state.hypotheses[state.lround] = msg.content
                     elif "evolving code" in tags:
                         msg.content = [i for i in msg.content if i]
+                        # Also store under the short key so downstream consumers
+                        # that read state.msgs[round]["evolving code"] can find it.
+                        state.msgs[state.lround]["evolving code"].append(msg)
                     elif "evolving feedback" in tags:
                         total_len = len(msg.content)
                         none_num = total_len - len(msg.content)
diff --git a/rdagent/log/utils/__init__.py b/rdagent/log/utils/__init__.py
index 44edb67e6..89518ba85 100644
--- a/rdagent/log/utils/__init__.py
+++ b/rdagent/log/utils/__init__.py
@@ -99,7 +99,12 @@ def extract_evoid(tag: str) -> str | None:
 def extract_json(log_content: str) -> dict | None:
     match = re.search(r"\{.*\}", log_content, re.DOTALL)
     if match:
-        return cast(dict, json.loads(match.group(0)))
+        raw = match.group(0)
+        # Normalize Python-style booleans/null that some LLM providers return
+        raw = re.sub(r"\bTrue\b", "true", raw)
+        raw = re.sub(r"\bFalse\b", "false", raw)
+        raw = re.sub(r"\bNone\b", "null", raw)
+        return cast(dict, json.loads(raw))
     return None