perf: implement settings singleton pattern (#134)

* perf: implement settings singleton pattern

* chore: run pre-commit hook

Author: mustafahasankhan

modelcontextprotocol/.cursor/rules/project-structure.mdc

@@ -117,13 +117,13 @@ Factory for creating and configuring the Atlan client using application settings
 ```python
 import logging
 from pyatlan.client.atlan import AtlanClient
-from settings import Settings
+from settings import get_settings
 
 logger = logging.getLogger(__name__)
 
 def get_atlan_client() -> AtlanClient:
     """Create an Atlan client instance using settings loaded from environment."""
-    settings = Settings()
+    settings = get_settings()
     try:
         client = AtlanClient(
             base_url=settings.ATLAN_BASE_URL, api_key=settings.ATLAN_API_KEY
@@ -134,6 +134,22 @@ def get_atlan_client() -> AtlanClient:
     except Exception as e:
         logger.error(f"Error creating Atlan client: {e}")
         raise Exception(f"Error creating Atlan client: {e}")
+
+_settings: Optional[Settings] = None
+
+
+def get_settings() -> Settings:
+    """
+    Get the singleton Settings instance.
+    Loads settings once from environment/file and reuses the instance.
+
+    Returns:
+        Settings: The singleton settings instance
+    """
+    global _settings
+    if _settings is None:
+        _settings = Settings()
+    return _settings
 ```
 
 ### tools/ Directory

modelcontextprotocol/client.py

@@ -4,7 +4,7 @@
 from typing import Optional
 
 from pyatlan.client.atlan import AtlanClient
-from settings import Settings
+from settings import get_settings
 
 logger = logging.getLogger(__name__)
 
@@ -24,7 +24,7 @@ def get_atlan_client() -> AtlanClient:
     global _client_instance
 
     if _client_instance is None:
-        settings = Settings()
+        settings = get_settings()
         try:
             _client_instance = AtlanClient(
                 base_url=settings.ATLAN_BASE_URL, api_key=settings.ATLAN_API_KEY

modelcontextprotocol/settings.py

@@ -1,5 +1,6 @@
 """Configuration settings for the application."""
 
+from typing import Optional
 from pydantic_settings import BaseSettings
 from version import __version__ as MCP_VERSION
 
@@ -29,3 +30,20 @@ class Config:
         extra = "allow"
         # Allow case-insensitive environment variables
         case_sensitive = False
+
+
+_settings: Optional[Settings] = None
+
+
+def get_settings() -> Settings:
+    """
+    Get the singleton Settings instance.
+    Loads settings once from environment/file and reuses the instance.
+
+    Returns:
+        Settings: The singleton settings instance
+    """
+    global _settings
+    if _settings is None:
+        _settings = Settings()
+    return _settings