Social metadata from your page

Write a title and description once. Unify uses the final composed title for og:title, the final description for og:description, and the resolved canonical for og:url. No generator, extra configuration or browser script is needed. A page's explicit OG tags win; otherwise these derived values replace generic layout defaults. Missing source values leave layout fallbacks unchanged.

Shared layout

site/_layout.html can keep the settings that really are shared:

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>— Field Notes</title>
  <meta property="og:type" content="website">
  <meta property="og:site_name" content="Field Notes">
  <meta property="og:image" content="/assets/social.png">
</head>
<body><main></main></body>
</html>

Add your image at site/assets/social.png. These shared tags can equally live in a head include. Avoid putting one page's canonical in the layout: every page would inherit that address.

Pages

site/about.html:

<!doctype html>
<html lang="en">
<head>
  <title>Café &amp; code</title>
  <meta name="description" content="A &quot;small&quot; guide to &lt;good&gt; coffee &amp; code.">
</head>
<body><h1>Café &amp; code</h1><p>Bring a mug and something to make.</p></body>
</html>

site/start.md:

---
title: Start here
description: Find your first workshop project.
---
# Start here

Choose something you would like to make.

Build from the project root:

unify build --pretty-urls --base-url https://example.com/notes/

The HTML page gets og:title of Café & code — Field Notes, its own description, and og:url of https://example.com/notes/about/. The Markdown page gets Start here — Field Notes, its own description, and https://example.com/notes/start/. The suffix is part of the final title; Unify does not guess which punctuation separates a site name. Both inherit the shared image at https://example.com/notes/assets/social.png. Escaping preserves quotes, ampersands and angle brackets as text.

Overrides

To use different sharing copy, put explicit tags in the HTML page's head, directly or through a page-head include:

<meta property="og:title" content="A different title for sharing">
<meta property="og:description" content="Coffee, code, and a place to start.">
<meta property="og:url" content="/about.html">

Or add these frontmatter fields to the Markdown page:

og:title: Your next project starts here
og:description: Pick a project and follow along.
og:url: /start.md

Explicit page tags win even when their content is empty. Repeated page tags stay repeated, as with ordinary head merging. An override in a layout or layout-head include is a fallback; it does not prevent a page's final title, description or canonical supplying the corresponding value. Body metadata and tags inside <template> do not override the head.

No description means no generated og:description; no canonical means no generated og:url. Without --base-url, title and description still work. --canonical none disables automatic canonical creation, but an authored canonical can still supply og:url. No other Open Graph fields or Twitter tags are generated: author them if needed.

Audit and catalog read the same final metadata crawlers receive. The source inventory remains source-only and does not contain these generated defaults. The executable examples and precedence cases are covered by tests/conformance/social-metadata.test.js.