test_authentication

Verify the validity of your Kroger authentication token to ensure secure access to grocery shopping features like store finding and cart management.

Instructions

    Test if the current authentication token is valid.
    
    Returns:
        Dictionary indicating authentication status

Input Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Implementation Reference

src/kroger_mcp/tools/profile_tools.py:55-99 (handler)

The main execution logic for the 'test_authentication' tool. It checks the validity of the current authentication token using the shared authenticated client, provides detailed status including refresh token availability, and handles errors gracefully.

@mcp.tool()
async def test_authentication(ctx: Context = None) -> Dict[str, Any]:
    """
    Test if the current authentication token is valid.
    
    Returns:
        Dictionary indicating authentication status
    """
    if ctx:
        await ctx.info("Testing authentication token validity")
    
    try:
        client = get_authenticated_client()
        is_valid = client.test_current_token()
        
        if ctx:
            await ctx.info(f"Authentication test result: {'valid' if is_valid else 'invalid'}")
        
        result = {
            "success": True,
            "token_valid": is_valid,
            "message": f"Authentication token is {'valid' if is_valid else 'invalid'}"
        }
        
        # Check for refresh token availability
        if hasattr(client.client, 'token_info') and client.client.token_info:
            has_refresh_token = "refresh_token" in client.client.token_info
            result["has_refresh_token"] = has_refresh_token
            result["can_auto_refresh"] = has_refresh_token
            
            if has_refresh_token:
                result["message"] += ". Token can be automatically refreshed when it expires."
            else:
                result["message"] += ". No refresh token available - will need to re-authenticate when token expires."
        
        return result
        
    except Exception as e:
        if ctx:
            await ctx.error(f"Error testing authentication: {str(e)}")
        return {
            "success": False,
            "error": str(e),
            "token_valid": False
        }

src/kroger_mcp/server.py:76-76 (registration)
The registration point where profile_tools.register_tools(mcp) is called, which defines and registers the test_authentication tool using FastMCP's @mcp.tool() decorator.
```
profile_tools.register_tools(mcp)
```

src/kroger_mcp/tools/shared.py:56-118 (helper)

Supporting helper function get_authenticated_client() that provides the authenticated KrogerAPI client instance, handling token loading, validation, and refresh. Called directly in test_authentication.

def get_authenticated_client() -> KrogerAPI:
    """Get or create a user-authenticated client for cart operations
    
    This function attempts to load an existing token or prompts for authentication.
    In an MCP context, the user needs to explicitly call start_authentication and
    complete_authentication tools to authenticate.
    
    Returns:
        KrogerAPI: Authenticated client
        
    Raises:
        Exception: If no valid token is available and authentication is required
    """
    global _authenticated_client
    
    if _authenticated_client is not None and _authenticated_client.test_current_token():
        # Client exists and token is still valid
        return _authenticated_client
    
    # Clear the reference if token is invalid
    _authenticated_client = None
    
    try:
        load_and_validate_env(["KROGER_CLIENT_ID", "KROGER_CLIENT_SECRET", "KROGER_REDIRECT_URI"])
        
        # Try to load existing user token first
        token_file = ".kroger_token_user.json"
        token_info = load_token(token_file)
        
        if token_info:
            # Create a new client with the loaded token
            _authenticated_client = KrogerAPI()
            _authenticated_client.client.token_info = token_info
            _authenticated_client.client.token_file = token_file
            
            if _authenticated_client.test_current_token():
                # Token is valid, use it
                return _authenticated_client
            
            # Token is invalid, try to refresh it
            if "refresh_token" in token_info:
                try:
                    _authenticated_client.authorization.refresh_token(token_info["refresh_token"])
                    # If refresh was successful, return the client
                    if _authenticated_client.test_current_token():
                        return _authenticated_client
                except Exception:
                    # Refresh failed, need to re-authenticate
                    _authenticated_client = None
        
        # No valid token available, need user-initiated authentication
        raise Exception(
            "Authentication required. Please use the start_authentication tool to begin the OAuth flow, "
            "then complete it with the complete_authentication tool."
        )
    except Exception as e:
        if "Authentication required" in str(e):
            # This is an expected error when authentication is needed
            raise
        else:
            # Other unexpected errors
            raise Exception(f"Authentication failed: {str(e)}")

Kroger MCP Server