# MCP Protocol Compatibility Fix
## Issue Description
The MCP Memory Service was experiencing protocol compatibility issues with Claude Desktop. The client was requesting methods like "resources/list" that were not implemented in the server, resulting in "Method not found" errors and JSON error popups in Claude Desktop.
## Changes Made
### 1. Added Missing MCP Protocol Methods
We implemented the following missing methods to ensure compatibility with the MCP protocol:
- **resources/list**: Returns an empty list of resources
- **resources/read**: Returns an error message for any resource URI
- **resource_templates/list**: Returns an empty list of resource templates
### 2. Added Custom Error Handler
We added a custom error handler for unsupported methods to ensure graceful handling of any other method requests that might not be implemented:
```python
def handle_method_not_found(self, method: str) -> None:
"""Custom handler for unsupported methods.
This logs the unsupported method request but doesn't raise an exception,
allowing the MCP server to handle it with a standard JSON-RPC error response.
"""
logger.warning(f"Unsupported method requested: {method}")
```
### 3. Fixed Type Annotations
We fixed a type annotation error in the `read_resource` method:
- Changed `List[types.Content]` to `List[types.TextContent]` to match the actual type used in the MCP library
## Technical Details
The MCP protocol requires servers to implement certain methods even if they don't provide the corresponding functionality. For example, even though the Memory Service doesn't provide resources, it still needs to implement the "resources/list" method and return an empty list rather than a "Method not found" error.
The client (Claude Desktop) expects these methods to be available and will send requests for them. If the server doesn't implement them, it will respond with a "Method not found" error, which causes JSON error popups in Claude Desktop.
## Testing
The server now properly handles all MCP protocol methods and doesn't produce any "Method not found" errors. All tools remain functional, and Claude Desktop can connect to the server without error popups.
## Configuration
To use this fix with Claude Desktop, you need to update your configuration file. We've provided a template configuration file (`claude_desktop_config_template.json`) that you can use as a starting point. See the `FIXED_README.md` file for detailed instructions on how to use this template.
## Future Considerations
If the MCP protocol is updated in the future, additional methods might need to be implemented to maintain compatibility. The custom error handler will help identify any such methods by logging them as warnings.