diff --git a/backend/agent/run.py b/backend/agent/run.py
index bafe8ae2..33862c9f 100644
--- a/backend/agent/run.py
+++ b/backend/agent/run.py
@@ -38,8 +38,8 @@ async def run_agent(
 ):
     """Run the development agent with specified configuration."""
     
-    if not thread_manager:
-        thread_manager = ThreadManager()
+    thread_manager = ThreadManager()
+    
     client = await thread_manager.db.client
 
     # Get account ID from thread for billing checks
diff --git a/backend/agentpress/tool_registry.py b/backend/agentpress/tool_registry.py
index d237cd63..238b7b33 100644
--- a/backend/agentpress/tool_registry.py
+++ b/backend/agentpress/tool_registry.py
@@ -21,16 +21,11 @@ class ToolRegistry:
         get_xml_examples: Get examples of XML tool usage
     """
     
-    _instance = None
-    
-    def __new__(cls):
-        """Create or return singleton instance."""
-        if cls._instance is None:
-            cls._instance = super().__new__(cls)
-            cls._instance.tools = {}
-            cls._instance.xml_tools = {}
-            logger.debug("Initialized new ToolRegistry instance")
-        return cls._instance
+    def __init__(self):
+        """Initialize a new ToolRegistry instance."""
+        self.tools = {}
+        self.xml_tools = {}
+        logger.debug("Initialized new ToolRegistry instance")
     
     def register_tool(self, tool_class: Type[Tool], function_names: Optional[List[str]] = None, **kwargs):
         """Register a tool with optional function filtering.
diff --git a/backend/sandbox/sandbox.py b/backend/sandbox/sandbox.py
index 495792cf..43cd2e7c 100644
--- a/backend/sandbox/sandbox.py
+++ b/backend/sandbox/sandbox.py
@@ -8,7 +8,7 @@ from dotenv import load_dotenv
 from agentpress.tool import Tool
 from utils.logger import logger
 from utils.files_utils import clean_path
-from utils.thread_manager import ThreadManager
+from agentpress.thread_manager import ThreadManager
 
 load_dotenv()