diff --git a/openhands/core/config/mcp_config.py b/openhands/core/config/mcp_config.py
index a5fe534925..30c0b29b2f 100644
--- a/openhands/core/config/mcp_config.py
+++ b/openhands/core/config/mcp_config.py
@@ -1,6 +1,6 @@
 from urllib.parse import urlparse
 
-from pydantic import BaseModel, Field, ValidationError
+from pydantic import BaseModel, Field, ValidationError, model_validator
 
 
 class MCPSSEServerConfig(BaseModel):
@@ -44,6 +44,24 @@ class MCPConfig(BaseModel):
 
     model_config = {'extra': 'forbid'}
 
+    @staticmethod
+    def _normalize_sse_servers(servers_data: list[dict | str]) -> list[dict]:
+        """Helper method to normalize SSE server configurations."""
+        normalized = []
+        for server in servers_data:
+            if isinstance(server, str):
+                normalized.append({'url': server})
+            else:
+                normalized.append(server)
+        return normalized
+
+    @model_validator(mode='before')
+    def convert_string_urls(cls, data):
+        """Convert string URLs to MCPSSEServerConfig objects."""
+        if isinstance(data, dict) and 'sse_servers' in data:
+            data['sse_servers'] = cls._normalize_sse_servers(data['sse_servers'])
+        return data
+
     def validate_servers(self) -> None:
         """Validate that server URLs are valid and unique."""
         urls = [server.url for server in self.sse_servers]
@@ -77,13 +95,10 @@ class MCPConfig(BaseModel):
         try:
             # Convert all entries in sse_servers to MCPSSEServerConfig objects
             if 'sse_servers' in data:
+                data['sse_servers'] = cls._normalize_sse_servers(data['sse_servers'])
                 servers = []
                 for server in data['sse_servers']:
-                    if isinstance(server, dict):
-                        servers.append(MCPSSEServerConfig(**server))
-                    else:
-                        # Convert string URLs to MCPSSEServerConfig objects with no API key
-                        servers.append(MCPSSEServerConfig(url=server))
+                    servers.append(MCPSSEServerConfig(**server))
                 data['sse_servers'] = servers
 
             # Convert all entries in stdio_servers to MCPStdioServerConfig objects
@@ -96,6 +111,7 @@ class MCPConfig(BaseModel):
             # Create SSE config if present
             mcp_config = MCPConfig.model_validate(data)
             mcp_config.validate_servers()
+
             # Create the main MCP config
             mcp_mapping['mcp'] = cls(
                 sse_servers=mcp_config.sse_servers,
@@ -103,5 +119,4 @@ class MCPConfig(BaseModel):
             )
         except ValidationError as e:
             raise ValueError(f'Invalid MCP configuration: {e}')
-
         return mcp_mapping