""" Chat model wrapper to fix tool_calls args parsing issues. Some AI providers (like DeepSeek) return tool_calls.args as JSON strings instead of dictionaries, causing Pydantic validation errors. This wrapper monkey-patches the model to fix args before AIMessage construction. """ import json from typing import Any, List, Optional, Dict from functools import wraps from langchain_core.messages import AIMessage, BaseMessage class ToolCallArgsParsingWrapper: """ Wrapper around ChatOpenAI that fixes tool_calls args parsing. This fixes the Pydantic validation error: "Input should be a valid dictionary [type=dict_type, input_value='...', input_type=str]" Works by monkey-patching _create_chat_result to parse string args before AIMessage construction. """ def __init__(self, model: Any, **kwargs): """ Initialize wrapper around a chat model. Args: model: The chat model to wrap (should be ChatOpenAI instance) **kwargs: Additional parameters (ignored, for compatibility) """ self.wrapped_model = model self._patch_model() def _patch_model(self): """Monkey-patch the model's _create_chat_result to fix tool_calls args""" if not hasattr(self.wrapped_model, '_create_chat_result'): # Model doesn't have this method (e.g., MockChatModel), skip patching return original_create_chat_result = self.wrapped_model._create_chat_result @wraps(original_create_chat_result) def patched_create_chat_result(response: Any, generation_info: Optional[Dict] = None): """Patched version that fixes tool_calls args before AIMessage construction""" # Fix tool_calls in the response dict before passing to original method response_dict = response if isinstance(response, dict) else response.model_dump() # DIAGNOSTIC: Log response structure print(f"\n[DEBUG] Response keys: {response_dict.keys()}") if 'choices' in response_dict: print(f"[DEBUG] Number of choices: {len(response_dict['choices'])}") for i, choice in enumerate(response_dict['choices']): print(f"[DEBUG] Choice {i} keys: {choice.keys()}") if 'message' in choice: message = choice['message'] print(f"[DEBUG] Message keys: {message.keys()}") # Check tool_calls structure if 'tool_calls' in message and message['tool_calls']: print(f"[DEBUG] Found {len(message['tool_calls'])} tool_calls") for j, tc in enumerate(message['tool_calls']): print(f"[DEBUG] tool_calls[{j}] keys: {tc.keys()}") if 'function' in tc: print(f"[DEBUG] tool_calls[{j}].function keys: {tc['function'].keys()}") if 'arguments' in tc['function']: args = tc['function']['arguments'] print(f"[DEBUG] tool_calls[{j}].function.arguments type: {type(args)}") print(f"[DEBUG] tool_calls[{j}].function.arguments value: {repr(args)[:200]}") if 'invalid_tool_calls' in message: print(f"[DEBUG] Found invalid_tool_calls: {len(message['invalid_tool_calls'])} items") for j, inv in enumerate(message['invalid_tool_calls']): print(f"[DEBUG] invalid_tool_calls[{j}] keys: {inv.keys()}") if 'args' in inv: print(f"[DEBUG] invalid_tool_calls[{j}].args type: {type(inv['args'])}") print(f"[DEBUG] invalid_tool_calls[{j}].args value: {inv['args']}") # REMOVED: No conversion needed yet - gathering data first # Call original method with unmodified response return original_create_chat_result(response_dict, generation_info) # Replace the method self.wrapped_model._create_chat_result = patched_create_chat_result @property def _llm_type(self) -> str: """Return identifier for this LLM type""" if hasattr(self.wrapped_model, '_llm_type'): return f"wrapped-{self.wrapped_model._llm_type}" return "wrapped-chat-model" def __getattr__(self, name: str): """Proxy all other attributes/methods to the wrapped model""" return getattr(self.wrapped_model, name) def bind_tools(self, tools: Any, **kwargs): """ Bind tools to the wrapped model. Since we patch the model in-place, we can just delegate to the wrapped model. """ return self.wrapped_model.bind_tools(tools, **kwargs) def bind(self, **kwargs): """ Bind settings to the wrapped model. Since we patch the model in-place, we can just delegate to the wrapped model. """ return self.wrapped_model.bind(**kwargs)