Documentation

User Agents

What is a User-Agent?

A User-Agent is a small piece of information your browser, app, or tool sends along with each request to a server. It identifies the software making the request—such as the browser type, version, and operating system.

Servers use the User-Agent string to:

  • Adjust responses for compatibility with different browsers or devices.
  • Collect statistics about visitors.
  • Detect unusual or invalid requests.

Filters

api_security_trusted_user_agents – Only use the trusted list for essential WordPress functionality that must bypass all security checks.

PHP
/**
 * Add custom trusted user agents (use with caution)
 */
function my_custom_trusted_user_agents( $trusted_patterns, $user_agent ) {
    $custom_patterns = array(
        '*EssentialWordPressTool*',
        '*CriticalSystemComponent*',
    );
    
    return array_merge( $trusted_patterns, $custom_patterns );
}
add_filter( 'api_security_trusted_user_agents', 'my_custom_trusted_user_agents', 10, 2 );

api_security_allowed_user_agents – the list of allowed user agent patterns.

PHP
/**
 * Add custom allowed user agents for speed testing tools
 */
function my_custom_allowed_user_agents( $allowed_patterns, $user_agent ) {
    // Add your custom patterns here
    $custom_patterns = array(
        '*MyCustomTool*',
        '*AnotherSpeedTest*',
        '*PerformanceMonitor*',
    );
    
    return array_merge( $allowed_patterns, $custom_patterns );
}
add_filter( 'api_security_allowed_user_agents', 'my_custom_allowed_user_agents', 10, 2 );

Contants

API_SECURITY_UA_REQUIRED

Need the User-Agent to be required for requests, set this constant in your wp-config.php file to TRUE.

PHP
define( 'API_SECURITY_UA_REQUIRED', true );