Gary Pendergast

OpenGraph Fallback Embed adds a custom Gutenberg block and an auto-embed fallback that renders rich link cards using OpenGraph metadata from any URL.
Features:
<ul>
<li>OpenGraph Embed block — Paste any URL to embed it as a styled card showing the page’s title, description, image, and site name.</li>
<li>Auto-embed fallback — When WordPress can’t find an oEmbed provider for a URL pasted on its own line, this plugin automatically fetches the page’s OpenGraph tags and renders a card instead of a plain link.</li>
<li>Graceful degradation — Falls back to Twitter Card meta tags, then to HTML <code><title></code> and <code><meta name="description"></code> when OpenGraph tags are missing.</li>
<li>Transient caching — Fetched metadata is cached for 7 days to minimise external requests.</li>
</ul>
<h3>Development</h3>
The source code for this plugin, including unminified JavaScript and CSS, is available on GitHub:
<a href="https://github.com/pento/opengraph-fallback-embed" rel="nofollow ugc">OpenGraph Fallback Embed on GitHub</a>
The plugin uses <a href="https://developer.wordpress.org/block-editor/reference-guides/packages/packages-scripts/" rel="nofollow ugc">@wordpress/scripts</a> for building. Source files are in the <code>src/</code> directory. See the repository README for build instructions.

OpenGraph Fallback Embed

Provides an embed block and auto-embed fallback based on a site's OpenGraph tags when no other embed handler matches the URL.

Piyush Mishra

The Open Graph protocol enables any web page to become a rich object in a social graph. For instance, this is used on Facebook to enable any web page to have the same functionality as a Facebook Page.
While many different technologies and schemas exist and could be combined together, there isn’t a single technology which provides enough information to richly represent any web page within the social graph. The Open Graph protocol builds on these existing technologies and gives developers one thing to implement. Developer simplicity is a key goal of the Open Graph protocol which has informed many of the technical design decisions.
<h4>For Developers</h4>
Use <code>add_action('open_graph_head_pre','your_function');</code> and <code>add_action('open_graph_head_post','your_function');</code> to edit the meta data. For an instance of the class.
Always use <code>open_graph_instance()</code> 
Read more on the Plugin URI > <a href="http://www.piyushmishra.com/plugins/open-graph.html" title="Plugin URI" rel="nofollow ugc">Open Graph WP implementation</a> or check out the FAQs

Open Graph WP implementation

Implements the Open Graph Protocol on a WordPress installation. Can be used by other plugins as a dependency.

OpenGraph Fallback Embed vs Open Graph WP implementation