Markdown features

Zeku’s live preview renders standard markdown and a set of popular extensions. Your site renders the extensions only if its Markdown settings turn them on or a plugin adds them, so Zeku reads those settings and shows you what your site will show.

Standard markdown

These render on every Astro site:

• Headings, paragraphs, bold, italic, inline code, and strikethrough
• Links and images
• Ordered, unordered, and task lists
• Block quotes and horizontal rules
• Tables
• Fenced code blocks, highlighted by language
• Footnotes
• Raw HTML, including forms

Extensions

Feature	Write it as	Needs on your site
Callouts	> [!note] on a quote’s first line	A callout plugin, or a theme that has one
Admonitions	:::note … :::	Starlight, or directive support
Math	$x^2$ inline, $$ for a block	Math support, such as KaTeX
Mermaid diagrams	A ```mermaid code block	A Mermaid integration
Highlights	==text==	A highlight plugin
Comments	%%text%%	A plugin that removes them
Wikilinks and embeds	[[post]] and ![[image.png]]	A wikilink plugin
Video, audio, and social embeds	, , or an embed code block with a URL	A theme or plugin that embeds them
Image grids	Two or more images in a paragraph of their own	A grid plugin, as Astro Modular and Axis have; see Image grids
Heading ids	## Title {#id}	Heading attribute support

Zeku draws Mermaid diagrams with Pele, the renderer Obsidian uses. Diagrams take their colors and fonts from Zeku’s theme, follow light and dark mode, and lay out again to fit the editor’s width. Click a diagram to edit its code. A site that renders diagrams with merman, as Firefly does, gets merman’s rules for labels, so a chart reads the same in Zeku as on the site. Mermaid drawn by in Settings > Content shows which renderer your site uses and corrects the detection.

Callouts fold like Obsidian’s: add - or + after the type, as in > [!tip]-, to start one closed or open.

Only the ![](url) form embeds. A plain link or a bare URL stays a link, as in Obsidian.

Embed code

Paste the embed code a site gives you, such as YouTube’s or Vimeo’s Share > Embed, a Spotify episode’s, or X’s Embed post, straight into an entry. It’s HTML, which every Astro site passes through, so it works without a plugin: a player plays in the editor, and an X post shows its card, the same as on your site. Embed code split across lines, or wrapped in a <div> to make a video responsive, works too.

To edit an embed’s code, arrow onto it with ↑ or ↓, or click just outside the player. The code shows in place of the embed until the cursor leaves it. Tables, Mermaid diagrams, and math work the same way.

What your site renders

Every time you open a project, Zeku reads your astro.config file: the Markdown processor, the features it turns on, and each remark and rehype plugin. For a plugin from npm, Zeku knows the common ones by name and reads the rest from node_modules. For a plugin your theme keeps in its own folder, Zeku reads the file itself to see which syntax it handles, and the same goes for an integration kept there, along with any package that file wraps. Nothing runs, and nothing is written.

Anything your site won’t render, Zeku doesn’t render either. A callout on a site with no callout plugin looks like the plain quote your site will show, with a dotted underline under [!note]. Hover over any underlined syntax to see what your site does with it instead.

Astro 7 renders less by default

Since Astro 7, sites render Markdown with Sätteri by default, with no plugins. On a new site, the extensions above show as plain text until you turn them on or add a plugin. A site built from a theme often already has them.

To see what Zeku found, open Settings > Content. Each feature lists the plugin that renders it, or what your site does without one. If Zeku has one wrong, choose Supported or Not supported next to it. Your choice is saved to .zeku/config.json, so it follows the project to any computer. Choose Auto to go back to what Zeku detects.

If Zeku can’t read your config, it renders everything and marks nothing.

Comments

Text between %% marks is a comment, as in Obsidian: a note to yourself that isn’t meant for the page. Zeku fades comments while you edit and hides them in reading view.

A comment stays private only if your site removes it. Themes built for Obsidian users, such as Astro Modular and Axis, do. On a site that doesn’t, Zeku keeps comments visible in reading view and underlines each one, because it will be published with the post, and Publish warns you before a post with a comment in it goes live.