diff --git a/antora-playbook.yml b/antora-playbook.yml
index 279a37c9f3..87141ef60b 100644
--- a/antora-playbook.yml
+++ b/antora-playbook.yml
@@ -1,8 +1,26 @@
+# The contents of this file are subject to the terms of the Common Development and
+# Distribution License (the License). You may not use this file except in compliance with the
+# License.
+#
+# You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
+# specific language governing permission and limitations under the License.
+#
+# When distributing Covered Software, include this CDDL Header Notice in each file and include
+# the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
+# Header, with the fields enclosed by brackets [] replaced by your own identifying
+# information: "Portions copyright [year] [name of copyright owner]".
+#
+# Copyright 2024-2026 3A Systems, LLC.
+
 site:
   title: Open Identity Platform Documentation
   start_page: ROOT::index.adoc
   url: https://doc.openidentityplatform.org
-  robots: allow
+  # Antora writes robots verbatim: keep the Sitemap host in sync with site.url above.
+  robots: |
+    User-agent: *
+    Allow: /
+    Sitemap: https://doc.openidentityplatform.org/sitemap.xml
   keys:
     google_analytics: 'G-TFFQQ60TMD'
     google_site_verification: 'gB-OZuT18mmNEL-k5UNMHmNWQX5Wv46GnWWs1XZxZeE'
diff --git a/supplemental-ui/partials/head-meta.hbs b/supplemental-ui/partials/head-meta.hbs
index f836c48a12..cff623e272 100644
--- a/supplemental-ui/partials/head-meta.hbs
+++ b/supplemental-ui/partials/head-meta.hbs
@@ -13,8 +13,21 @@
  * information: "Portions copyright [year] [name of copyright owner]".
  *
  * Copyright 2017 ForgeRock AS.
- * Portions copyright 2024 3A Systems LLC.
+ * Portions copyright 2024-2026 3A Systems LLC.
 -->
 {{#with site.keys.googleSiteVerification}}
 <meta name="google-site-verification" content="{{this}}" />
-{{/with}}
\ No newline at end of file
+{{/with}}
+{{!-- The UI emits <meta name="description"> only for a page that sets :description:; fall back to a generated one --}}
+{{#unless page.description}}
+<meta name="description" content="{{> meta-description}}">
+{{/unless}}
+<meta property="og:type" content="website">
+<meta property="og:site_name" content="{{site.title}}">
+<meta property="og:title" content="{{{detag (or page.title site.title) attribute=true}}}">
+<meta property="og:description" content="{{#if page.description}}{{{detag page.description attribute=true}}}{{else}}{{> meta-description}}{{/if}}">
+{{#with page.canonicalUrl}}
+<meta property="og:url" content="{{{this}}}">
+{{/with}}
+<meta property="og:image" content="https://avatars.githubusercontent.com/u/30845478?s=280&amp;v=4">
+<meta name="twitter:card" content="summary">
diff --git a/supplemental-ui/partials/meta-description.hbs b/supplemental-ui/partials/meta-description.hbs
new file mode 100644
index 0000000000..f558695dae
--- /dev/null
+++ b/supplemental-ui/partials/meta-description.hbs
@@ -0,0 +1,21 @@
+{{!--
+ * The contents of this file are subject to the terms of the Common Development and
+ * Distribution License (the License). You may not use this file except in compliance with the
+ * License.
+ *
+ * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
+ * specific language governing permission and limitations under the License.
+ *
+ * When distributing Covered Software, include this CDDL Header Notice in each file and include
+ * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
+ * Header, with the fields enclosed by brackets [] replaced by your own identifying
+ * information: "Portions copyright [year] [name of copyright owner]".
+ *
+ * Copyright 2026 3A Systems, LLC.
+--}}
+{{!-- Description of a page that sets no :description:, used by head-meta.hbs --}}
+{{~#if (and page.component (ne page.component.name 'ROOT'))~}}
+{{{detag page.title attribute=true}}} - {{page.component.title}} documentation, Open Identity Platform
+{{~else~}}
+Documentation of the Open Identity Platform: OpenAM access management, OpenDJ directory services, OpenIDM identity management and OpenIG identity gateway
+{{~/if~}}