diff --git a/lib/html_head.typ b/lib/html_head.typ
index 3fee2c2..37f39ce 100644
--- a/lib/html_head.typ
+++ b/lib/html_head.typ
@@ -13,9 +13,9 @@
   og-type: "website",
   /// Name of the site for metadata of the page
   site-name: none,
-  /// Description of the site for metadata #TODO default to document.description
+  /// Description of the site for metadata, default to document.description
   description: none,
-  /// Author of the site for metadata #TODO default to document.author
+  /// Author of the site for metadata, default to document.author
   author: none,
   /// Additional stylesheet for the page: must be a list of url
   stylesheets: (),
@@ -24,7 +24,11 @@
 ) = {
   html.head({
     html.meta(charset: "utf-8")
-    html.title(title)
+    if title != none {
+      html.title(title)
+    } else { context {
+      html.title(document.title)
+    }}
     // html.meta(http-equiv: "Content-Language", content: "en") Obsolet, now use the html tag attr "lang" instead
 
     // The width=device-width part sets the width of the page to follow the screen-width of the device (which will vary depending on the device).
@@ -39,7 +43,14 @@
     }
 
     // Open Graph (https://ogp.me/), used by social media for link previsualisation
-    chtml.meta-og(property: "og:title", content: repr(title))
+    if title != none {
+      chtml.meta-og(property: "og:title", content: title)
+    } else { context {
+      if document.title != none {
+        assert(document.title.has("text"), message: "document.title must be a string")
+        chtml.meta-og(property: "og:title", content: document.title.at("text"))
+      }
+    }}
     chtml.meta-og(property: "og:type", content: og-type)
     chtml.meta-og(property: "og:url", content: url)
     if icon != none {
@@ -61,10 +72,19 @@
     }
     if description != none {
       html.meta(name: "description", content: description)
-    }
+    } else { context {
+      if document.description != none {
+        assert(document.description.has("text"), message: "document.description must be a string")
+        html.meta(name: "description", content: document.description.at("text"))
+      }
+    }}
     if author != none {
       html.meta(name: "author", content: author)
-    }
+    } else { context {
+      if document.author != () {
+        html.meta(name: "author", content: document.author.join(", "))
+      }
+    }}
 
     ```raw-css
     :root {