Plugin to add Cache-Control headers to robots.txt

robots-txt-cache.php

+<?php
+/*
+ * Plugin Name: A/I - Robots.txt caching
+ * Description: Add cache-control headers to robots.txt
+ * Version: 0.0.1
+ * Author: Autistici/Inventati
+ * Author URI: https://autistici.org
+ */
+
+function ai_robots_txt_add_cache_headers() {
+    header("Cache-Control", "max-age=86400");
+}
+
+add_action('do_robotstxt', 'ai_robots_txt_add_cache_headers');