Getting started

Sigla is a native macOS Markdown reader. It renders GitHub Flavored Markdown plus KaTeX math, Mermaid, Vega-Lite, PlantUML, Graphviz, Gherkin, and CSV/TSV tables — all offline, all rendered the same way every time.

This page gets you from “nothing installed” to “reading your first document” in under a minute, then points at the rest of the documentation.

Install

Sigla is distributed through Homebrew:

brew tap slantedt/tap
brew install --cask sigla

This installs Sigla.app to /Applications and the mdv command-line tool to your PATH.

[!NOTE] The cask installs three CLI names that all run the same mdv binary: mdv (canonical), sigla (forward-looking), and mdview (legacy alias). They all do the same thing. mdview is preserved as a sunset alias for users coming from the pre-rename builds; it prints a one-line deprecation notice on stderr but otherwise behaves identically.

[!TIP] Coming from the old install? brew install --cask mdview from tvaisanen/tap still works — Homebrew’s tap-migration map transparently redirects it to slantedt/tap/sigla. You don’t need to brew untap anything.

To verify the install:

mdv --version

Open your first file

There are three ways to open a Markdown file in Sigla:

From the Dock. Drag any .md or .markdown file onto the Sigla icon in the Dock.
From the menu bar. With Sigla focused, press ⌘O (File → Open…) and pick a file.
From the terminal. Run mdv ./README.md (or any path). Sigla launches if it isn’t running and opens the file.

To open a whole folder of Markdown — recommended for any project bigger than one file — press ⌘⇧O (File → Open Folder…) instead. You get a sidebar, table of contents, frontmatter panel, and cross-file wikilinks. See Folder workspace.

What renders out of the box

Sigla ships four bundled extensions inside the signed app — no separate install, no configuration:

Extension	Triggers on fence label	Needs an external binary?
Mermaid (built-in)	```mermaid	No
Vega-Lite (built-in)	```vega-lite	No
PlantUML	```plantuml	Yes — `brew install plantuml`
Graphviz	```dot or ```graphviz	Yes — `brew install graphviz`
Gherkin	```gherkin	No

Math ( $x^2$ , $$\sum x_i$$, ```math fences) renders via bundled KaTeX. CSV and TSV fences render as tables. None of this requires configuration.

When a process-backed extension’s binary isn’t installed (PlantUML, Graphviz) the fence renders a placeholder telling you which brew install to run. The source stays visible — nothing disappears.

For the full list and how to add your own, see Extensions overview.

Where settings live

Open settings with ⌘, (Sigla → Settings…). Five panes:

Themes — built-in document themes plus any custom CSS themes you’ve dropped in ~/.config/sigla/themes/. See Themes.
Renderers — toggle individual built-in renderers and extensions on or off. See Settings — Renderers.
Comments — opt-in to inline comments and highlights. See Comments and highlights.

Settings persist in UserDefaults under the com.slantedt.sigla domain. Most changes take effect immediately on the active document.

Where to read next

Keyboard shortcuts — every binding Sigla uses.
CLI reference — the mdv command surface in detail.
Using with Claude — drop the bundled skills into your Claude config so Claude knows Sigla without re-explaining.
Upgrading from MarkdownViewer — if you ran the app under its old name.

This documentation itself ships inside the app — Help → Sigla Documentation (⌘?) opens this folder as a Sigla workspace.