mu-plugin for /.well-known/feeds

well-known-feeds.php

<?php
/*
Plugin Name: Custom OPML Feed
Description: Implements a custom OPML feed at /.well-known/feeds/
Author: cagrimmett
*/

// Add custom rewrite rule
function custom_opml_rewrite_rule() {
	add_rewrite_rule( '^\.well-known/feeds/?$', 'index.php?custom_opml_feed=1', 'top' );
}
add_action( 'init', 'custom_opml_rewrite_rule' );

// Add custom query variable
function custom_opml_query_vars( $query_vars ) {
	$query_vars[] = 'custom_opml_feed';
	return $query_vars;
}
add_filter( 'query_vars', 'custom_opml_query_vars' );

// Serve OPML file
function serve_custom_opml_feed() {
	if ( get_query_var( 'custom_opml_feed' ) ) {
		$opml_file_path = 'https://cagrimmett.com/opml/well-known-feeds.opml'; // Replace with your actual file path
		header( 'Content-Type: text/x-opml' );
		readfile( $opml_file_path );
		exit;
	}
}
add_action( 'template_redirect', 'serve_custom_opml_feed' );