feat: add regex fallback parser to recover malformed JSON tool calls

helpers/extract_tools.py

@@ -3,22 +3,66 @@
 import regex, re
 from helpers.modules import load_classes_from_file, load_classes_from_folder # keep here for backwards compatibility
 from typing import Any
+import logging
+
+LOG = logging.getLogger(__name__)
 
 def json_parse_dirty(json: str) -> dict[str, Any] | None:
     if not json or not isinstance(json, str):
         return None
 
+    # Attempt 1: Standard parser
     ext_json = extract_json_object_string(json.strip())
     if ext_json:
         try:
             data = DirtyJson.parse_string(ext_json)
             if isinstance(data, dict):
                 return data
         except Exception:
-            # If parsing fails, return None instead of crashing
-            return None
+            pass
+
+    # Attempt 2: Regex fallback - extract tool_name and tool_args from partial output
+    try:
+        result = _regex_fallback(json)
+        if result:
+            LOG.debug("json_parse_dirty: recovered via regex fallback")
+            return result
+    except Exception as e:
+        LOG.debug(f"json_parse_dirty: regex fallback failed: {e}")
+
     return None
 
+
+def _regex_fallback(text: str) -> dict[str, Any] | None:
+    """Try to extract tool_name and tool_args from malformed JSON using regex."""
+    # Find tool_name value
+    tn_match = re.search(
+        r'"tool_name"\s*:\s*"([^"]+)"', text
+    )
+    if not tn_match:
+        return None
+    tool_name = tn_match.group(1)
+
+    # Find tool_args object
+    ta_match = re.search(
+        r'"tool_args"\s*:\s*(\{[^}]*\})', text, re.DOTALL
+    )
+    if not ta_match:
+        # Return with empty args if we at least have a tool_name
+        return {"tool_name": tool_name, "tool_args": {}}
+
+    args_str = ta_match.group(1)
+    try:
+        args = DirtyJson.parse_string(args_str)
+        if isinstance(args, dict):
+            return {"tool_name": tool_name, "tool_args": args}
+    except Exception:
+        pass
+
+    # Last resort: return tool_name with raw args string
+    return {"tool_name": tool_name, "tool_args": {"_raw": args_str}}
+
+
 def extract_json_root_string(content: str) -> str | None:
     if not content or not isinstance(content, str):
         return None