diff --git a/api/model_day_executor.py b/api/model_day_executor.py
index 23b8489..1b2d5e6 100644
--- a/api/model_day_executor.py
+++ b/api/model_day_executor.py
@@ -11,6 +11,7 @@ This module provides:
 
 import logging
 import os
+import asyncio
 from typing import Dict, Any, Optional, List, TYPE_CHECKING
 from pathlib import Path
 
@@ -118,7 +119,7 @@ class ModelDayExecutor:
 
             # Run trading session
             logger.info(f"Running trading session for {self.model_sig} on {self.date}")
-            session_result = agent.run_trading_session(self.date)
+            session_result = asyncio.run(agent.run_trading_session(self.date))
 
             # Persist results to SQLite
             self._write_results_to_db(agent, session_result)
@@ -211,8 +212,10 @@ class ModelDayExecutor:
             init_date=config.get("date_range", {}).get("init_date", "2025-10-13")
         )
 
-        # Register agent (creates initial position if needed)
-        agent.register_agent()
+        # Note: In API mode, we don't call register_agent() because:
+        # - Position data is stored in SQLite database, not files
+        # - Database initialization is handled by JobManager
+        # - File-based position tracking is only for standalone/CLI mode
 
         return agent
 
diff --git a/tests/unit/test_model_day_executor.py b/tests/unit/test_model_day_executor.py
index da0b27b..648ad88 100644
--- a/tests/unit/test_model_day_executor.py
+++ b/tests/unit/test_model_day_executor.py
@@ -14,7 +14,7 @@ Tests verify:
 
 import pytest
 import json
-from unittest.mock import Mock, patch, MagicMock
+from unittest.mock import Mock, patch, MagicMock, AsyncMock
 from pathlib import Path
 
 
@@ -29,7 +29,8 @@ def create_mock_agent(positions=None, last_trade=None, current_prices=None,
     mock_agent.get_current_prices.return_value = current_prices or {}
     mock_agent.get_reasoning_steps.return_value = reasoning_steps or []
     mock_agent.get_tool_usage.return_value = tool_usage or {}
-    mock_agent.run_trading_session.return_value = session_result or {"success": True}
+    # run_trading_session is async, so use AsyncMock
+    mock_agent.run_trading_session = AsyncMock(return_value=session_result or {"success": True})
 
     return mock_agent