fix: resolve DeepSeek tool_calls args parsing validation error

Added ToolCallArgsParsingWrapper to handle AI providers (like DeepSeek)
that return tool_calls.args as JSON strings instead of dictionaries.

The wrapper monkey-patches ChatOpenAI's _create_chat_result method to
parse string arguments before AIMessage construction, preventing
Pydantic validation errors.

Changes:
- New: agent/chat_model_wrapper.py - Wrapper implementation
- Modified: agent/base_agent/base_agent.py - Wrap model during init
- Modified: CHANGELOG.md - Document fix as v0.4.1
- New: tests/unit/test_chat_model_wrapper.py - Unit tests

Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

CHANGELOG.md

@@ -7,7 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [0.4.0] - 2025-11-04
+## [0.4.1] - 2025-11-05
+
+### Fixed
+- Fixed Pydantic validation error for tool_calls when using DeepSeek and other AI providers that return `args` as JSON strings instead of dictionaries. Added `ToolCallArgsParsingWrapper` that monkey-patches ChatOpenAI's `_create_chat_result` method to parse string arguments before AIMessage construction.
+
+## [0.4.0] - 2025-11-05
 
 ### BREAKING CHANGES
 
@@ -130,6 +135,49 @@ New `/results?reasoning=full` returns:
 - Test coverage increased with 36+ new comprehensive tests
 - Documentation updated with complete API reference and database schema details
 
+### Fixed
+- **Critical:** Intra-day position tracking for sell-then-buy trades (e20dce7)
+  - Sell proceeds now immediately available for subsequent buy orders within same trading session
+  - ContextInjector maintains in-memory position state during trading sessions
+  - Position updates accumulate after each successful trade
+  - Enables agents to rebalance portfolios (sell + buy) in single session
+  - Added 13 comprehensive tests for position tracking
+- **Critical:** Tool message extraction in conversation history (462de3a, abb9cd0)
+  - Fixed bug where tool messages (buy/sell trades) were not captured when agent completed in single step
+  - Tool extraction now happens BEFORE finish signal check
+  - Reasoning summaries now accurately reflect actual trades executed
+  - Resolves issue where summarizer saw 0 tools despite multiple trades
+- Reasoning summary generation improvements (6d126db)
+  - Summaries now explicitly mention specific trades executed (symbols, quantities, actions)
+  - Added TRADES EXECUTED section highlighting tool calls
+  - Example: 'sold 1 GOOGL and 1 AMZN to reduce exposure' instead of 'maintain core holdings'
+- Final holdings calculation accuracy (a8d912b)
+  - Final positions now calculated from actions instead of querying incomplete database records
+  - Correctly handles first trading day with multiple trades
+  - New `_calculate_final_position_from_actions()` method applies all trades to calculate final state
+  - Holdings now persist correctly across all trading days
+  - Added 3 comprehensive tests for final position calculation
+- Holdings persistence between trading days (aa16480)
+  - Query now retrieves previous day's ending position as current day's starting position
+  - Changed query from `date <=` to `date <` to prevent returning incomplete current-day records
+  - Fixes empty starting_position/final_position in API responses despite successful trades
+  - Updated tests to verify correct previous-day retrieval
+- Context injector trading_day_id synchronization (05620fa)
+  - ContextInjector now updated with trading_day_id after record creation
+  - Fixes "Trade failed: trading_day_id not found in runtime config" error
+  - MCP tools now correctly receive trading_day_id via context injection
+- Schema migration compatibility fixes (7c71a04)
+  - Updated position queries to use new trading_days schema instead of obsolete positions table
+  - Removed obsolete add_no_trade_record_to_db function calls
+  - Fixes "no such table: positions" error
+  - Simplified _handle_trading_result logic
+- Database referential integrity (9da65c2)
+  - Corrected Database default path from "data/trading.db" to "data/jobs.db"
+  - Ensures all components use same database file
+  - Fixes FOREIGN KEY constraint failures when creating trading_day records
+- Debug logging cleanup (1e7bdb5)
+  - Removed verbose debug logging from ContextInjector for cleaner output
+
 ## [0.3.1] - 2025-11-03
 
 ### Fixed

agent/base_agent/base_agent.py

@@ -33,6 +33,7 @@ from tools.deployment_config import (
 from agent.context_injector import ContextInjector
 from agent.pnl_calculator import DailyPnLCalculator
 from agent.reasoning_summarizer import ReasoningSummarizer
+from agent.chat_model_wrapper import ToolCallArgsParsingWrapper
 
 # Load environment variables
 load_dotenv()
@@ -208,10 +209,10 @@ class BaseAgent:
             # Create AI model (mock in DEV mode, real in PROD mode)
             if is_dev_mode():
                 from agent.mock_provider import MockChatModel
-                self.model = MockChatModel(date="2025-01-01")  # Date will be updated per session
+                base_model = MockChatModel(date="2025-01-01")  # Date will be updated per session
                 print(f"🤖 Using MockChatModel (DEV mode)")
             else:
-                self.model = ChatOpenAI(
+                base_model = ChatOpenAI(
                     model=self.basemodel,
                     base_url=self.openai_base_url,
                     api_key=self.openai_api_key,
@@ -219,6 +220,10 @@ class BaseAgent:
                     timeout=30
                 )
                 print(f"🤖 Using {self.basemodel} (PROD mode)")
+
+            # Wrap model to fix tool_calls args parsing
+            self.model = ToolCallArgsParsingWrapper(model=base_model)
+            print(f"✅ Applied tool_calls args parsing wrapper")
         except Exception as e:
             raise RuntimeError(f"❌ Failed to initialize AI model: {e}")
 
@@ -541,7 +546,7 @@ Summary:"""
 
         # Update mock model date if in dev mode
         if is_dev_mode():
-            self.model.date = today_date
+            self.model.wrapped_model.date = today_date
 
         # Get job_id from context injector
         job_id = self.context_injector.job_id if self.context_injector else get_config_value("JOB_ID")

agent/chat_model_wrapper.py

@@ -0,0 +1,98 @@
+"""
+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()
+
+            if 'choices' in response_dict:
+                for choice in response_dict['choices']:
+                    if 'message' in choice and 'tool_calls' in choice['message']:
+                        tool_calls = choice['message']['tool_calls']
+                        if tool_calls:
+                            for tool_call in tool_calls:
+                                if 'function' in tool_call and 'arguments' in tool_call['function']:
+                                    args = tool_call['function']['arguments']
+                                    # Parse string arguments to dict
+                                    if isinstance(args, str):
+                                        try:
+                                            tool_call['function']['arguments'] = json.loads(args)
+                                        except json.JSONDecodeError:
+                                            # Keep as string if parsing fails
+                                            pass
+
+            # Call original method with fixed 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)

tests/unit/test_chat_model_wrapper.py

@@ -0,0 +1,216 @@
+"""
+Unit tests for ChatModelWrapper - tool_calls args parsing fix
+"""
+
+import json
+import pytest
+from unittest.mock import Mock, AsyncMock
+from langchain_core.messages import AIMessage
+from langchain_core.outputs import ChatResult, ChatGeneration
+
+from agent.chat_model_wrapper import ToolCallArgsParsingWrapper
+
+
+class TestToolCallArgsParsingWrapper:
+    """Tests for ToolCallArgsParsingWrapper"""
+
+    @pytest.fixture
+    def mock_model(self):
+        """Create a mock chat model"""
+        model = Mock()
+        model._llm_type = "mock-model"
+        return model
+
+    @pytest.fixture
+    def wrapper(self, mock_model):
+        """Create a wrapper around mock model"""
+        return ToolCallArgsParsingWrapper(model=mock_model)
+
+    def test_fix_tool_calls_with_string_args(self, wrapper):
+        """Test that string args are parsed to dict"""
+        # Create message with tool_calls where args is a JSON string
+        message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "buy",
+                    "args": '{"symbol": "AAPL", "amount": 10}',  # String, not dict
+                    "id": "call_123"
+                }
+            ]
+        )
+
+        fixed_message = wrapper._fix_tool_calls(message)
+
+        # Check that args is now a dict
+        assert isinstance(fixed_message.tool_calls[0]['args'], dict)
+        assert fixed_message.tool_calls[0]['args'] == {"symbol": "AAPL", "amount": 10}
+
+    def test_fix_tool_calls_with_dict_args(self, wrapper):
+        """Test that dict args are left unchanged"""
+        # Create message with tool_calls where args is already a dict
+        message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "buy",
+                    "args": {"symbol": "AAPL", "amount": 10},  # Already a dict
+                    "id": "call_123"
+                }
+            ]
+        )
+
+        fixed_message = wrapper._fix_tool_calls(message)
+
+        # Check that args is still a dict
+        assert isinstance(fixed_message.tool_calls[0]['args'], dict)
+        assert fixed_message.tool_calls[0]['args'] == {"symbol": "AAPL", "amount": 10}
+
+    def test_fix_tool_calls_with_invalid_json(self, wrapper):
+        """Test that invalid JSON string is left unchanged"""
+        # Create message with tool_calls where args is an invalid JSON string
+        message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "buy",
+                    "args": 'invalid json {',  # Invalid JSON
+                    "id": "call_123"
+                }
+            ]
+        )
+
+        fixed_message = wrapper._fix_tool_calls(message)
+
+        # Check that args is still a string (parsing failed)
+        assert isinstance(fixed_message.tool_calls[0]['args'], str)
+        assert fixed_message.tool_calls[0]['args'] == 'invalid json {'
+
+    def test_fix_tool_calls_no_tool_calls(self, wrapper):
+        """Test that messages without tool_calls are left unchanged"""
+        message = AIMessage(content="Hello, world!")
+        fixed_message = wrapper._fix_tool_calls(message)
+
+        assert fixed_message == message
+
+    def test_generate_with_string_args(self, wrapper, mock_model):
+        """Test _generate method with string args"""
+        # Create a response with string args
+        original_message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "buy",
+                    "args": '{"symbol": "MSFT", "amount": 5}',
+                    "id": "call_456"
+                }
+            ]
+        )
+
+        mock_result = ChatResult(
+            generations=[ChatGeneration(message=original_message)]
+        )
+        mock_model._generate.return_value = mock_result
+
+        # Call wrapper's _generate
+        result = wrapper._generate(messages=[], stop=None, run_manager=None)
+
+        # Check that args is now a dict
+        fixed_message = result.generations[0].message
+        assert isinstance(fixed_message.tool_calls[0]['args'], dict)
+        assert fixed_message.tool_calls[0]['args'] == {"symbol": "MSFT", "amount": 5}
+
+    @pytest.mark.asyncio
+    async def test_agenerate_with_string_args(self, wrapper, mock_model):
+        """Test _agenerate method with string args"""
+        # Create a response with string args
+        original_message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "sell",
+                    "args": '{"symbol": "GOOGL", "amount": 3}',
+                    "id": "call_789"
+                }
+            ]
+        )
+
+        mock_result = ChatResult(
+            generations=[ChatGeneration(message=original_message)]
+        )
+        mock_model._agenerate = AsyncMock(return_value=mock_result)
+
+        # Call wrapper's _agenerate
+        result = await wrapper._agenerate(messages=[], stop=None, run_manager=None)
+
+        # Check that args is now a dict
+        fixed_message = result.generations[0].message
+        assert isinstance(fixed_message.tool_calls[0]['args'], dict)
+        assert fixed_message.tool_calls[0]['args'] == {"symbol": "GOOGL", "amount": 3}
+
+    def test_invoke_with_string_args(self, wrapper, mock_model):
+        """Test invoke method with string args"""
+        original_message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "buy",
+                    "args": '{"symbol": "NVDA", "amount": 20}',
+                    "id": "call_999"
+                }
+            ]
+        )
+
+        mock_model.invoke.return_value = original_message
+
+        # Call wrapper's invoke
+        result = wrapper.invoke(input=[])
+
+        # Check that args is now a dict
+        assert isinstance(result.tool_calls[0]['args'], dict)
+        assert result.tool_calls[0]['args'] == {"symbol": "NVDA", "amount": 20}
+
+    @pytest.mark.asyncio
+    async def test_ainvoke_with_string_args(self, wrapper, mock_model):
+        """Test ainvoke method with string args"""
+        original_message = AIMessage(
+            content="",
+            tool_calls=[
+                {
+                    "name": "sell",
+                    "args": '{"symbol": "TSLA", "amount": 15}',
+                    "id": "call_111"
+                }
+            ]
+        )
+
+        mock_model.ainvoke = AsyncMock(return_value=original_message)
+
+        # Call wrapper's ainvoke
+        result = await wrapper.ainvoke(input=[])
+
+        # Check that args is now a dict
+        assert isinstance(result.tool_calls[0]['args'], dict)
+        assert result.tool_calls[0]['args'] == {"symbol": "TSLA", "amount": 15}
+
+    def test_bind_tools_returns_wrapper(self, wrapper, mock_model):
+        """Test that bind_tools returns a new wrapper"""
+        mock_bound = Mock()
+        mock_model.bind_tools.return_value = mock_bound
+
+        result = wrapper.bind_tools(tools=[], strict=True)
+
+        # Check that result is a wrapper around the bound model
+        assert isinstance(result, ToolCallArgsParsingWrapper)
+        assert result.wrapped_model == mock_bound
+
+    def test_bind_returns_wrapper(self, wrapper, mock_model):
+        """Test that bind returns a new wrapper"""
+        mock_bound = Mock()
+        mock_model.bind.return_value = mock_bound
+
+        result = wrapper.bind(max_tokens=100)
+
+        # Check that result is a wrapper around the bound model
+        assert isinstance(result, ToolCallArgsParsingWrapper)
+        assert result.wrapped_model == mock_bound