diff --git a/mcp_server/src/config/schema.py b/mcp_server/src/config/schema.py
index a67f733d..76e802ff 100644
--- a/mcp_server/src/config/schema.py
+++ b/mcp_server/src/config/schema.py
@@ -201,7 +201,20 @@ class NeptuneProviderConfig(BaseModel):
     region: str | None = None
 
     def model_post_init(self, __context) -> None:
-        """Validate Neptune-specific requirements."""
+        """Validate and normalize Neptune-specific requirements."""
+        # Auto-detect and add protocol if missing
+        if not self.host.startswith(('neptune-db://', 'neptune-graph://', 'bolt://', 'http://', 'https://')):
+            # Check if it looks like a Neptune Analytics graph ID (starts with 'g-')
+            if self.host.startswith('g-'):
+                self.host = f'neptune-graph://{self.host}'
+            # Check if it contains 'neptune.amazonaws.com' (Neptune Database cluster)
+            elif 'neptune.amazonaws.com' in self.host:
+                self.host = f'neptune-db://{self.host}'
+            # Otherwise default to Neptune Database protocol
+            else:
+                self.host = f'neptune-db://{self.host}'
+
+        # Validate protocol is correct
         if not self.host.startswith(('neptune-db://', 'neptune-graph://')):
             raise ValueError(
                 'Neptune host must start with neptune-db:// or neptune-graph://\n'
diff --git a/mcp_server/src/services/factories.py b/mcp_server/src/services/factories.py
index 5c7bf4f1..2edd53f4 100644
--- a/mcp_server/src/services/factories.py
+++ b/mcp_server/src/services/factories.py
@@ -475,22 +475,49 @@ class DatabaseDriverFactory:
                 except Exception as e:
                     raise ValueError(f'AWS credential error: {e}') from e
 
-                # Load Neptune config
-                if config.providers.neptune:
-                    neptune_config = config.providers.neptune
-                else:
-                    from config.schema import NeptuneProviderConfig
-
-                    neptune_config = NeptuneProviderConfig()
-
-                # Environment overrides
+                # Load Neptune config and environment variables
                 import os
 
-                host = os.environ.get('NEPTUNE_HOST', neptune_config.host)
-                aoss_host = os.environ.get('AOSS_HOST', neptune_config.aoss_host)
-                port = int(os.environ.get('NEPTUNE_PORT', str(neptune_config.port)))
-                aoss_port = int(os.environ.get('AOSS_PORT', str(neptune_config.aoss_port)))
-                region_override = os.environ.get('AWS_REGION', region or neptune_config.region)
+                # Read environment variables first
+                env_host = os.environ.get('NEPTUNE_HOST')
+                env_aoss_host = os.environ.get('AOSS_HOST')
+                env_port = os.environ.get('NEPTUNE_PORT')
+                env_aoss_port = os.environ.get('AOSS_PORT')
+                env_region = os.environ.get('AWS_REGION')
+
+                if config.providers.neptune:
+                    neptune_config = config.providers.neptune
+                    # Apply environment overrides
+                    host = env_host or neptune_config.host
+                    aoss_host = env_aoss_host or neptune_config.aoss_host
+                    port = int(env_port) if env_port else neptune_config.port
+                    aoss_port = int(env_aoss_port) if env_aoss_port else neptune_config.aoss_port
+                    region_override = env_region or region or neptune_config.region
+                else:
+                    # No config provided, use environment variables with defaults
+                    from config.schema import NeptuneProviderConfig
+
+                    host = env_host or 'neptune-db://localhost'
+                    aoss_host = env_aoss_host
+                    port = int(env_port) if env_port else 8182
+                    aoss_port = int(env_aoss_port) if env_aoss_port else 443
+                    region_override = env_region or region
+
+                    # Create config with values to trigger validation
+                    neptune_config = NeptuneProviderConfig(
+                        host=host,
+                        aoss_host=aoss_host,
+                        port=port,
+                        aoss_port=aoss_port,
+                        region=region_override,
+                    )
+
+                    # Use normalized values from config (protocol may have been auto-added)
+                    host = neptune_config.host
+                    aoss_host = neptune_config.aoss_host
+                    port = neptune_config.port
+                    aoss_port = neptune_config.aoss_port
+                    region_override = neptune_config.region
 
                 if not aoss_host:
                     raise ValueError(