d2

Goldmark D2

Goldmark D2 is a Goldmark extension providing diagram support through D2.

Install

go get github.com/FurqanSoftware/goldmark-d2

Requires Go 1.27 or later, inherited from D2 v0.8.

Usage

import (
	d2 "github.com/FurqanSoftware/goldmark-d2"
	"github.com/d2lang/d2/d2layouts/d2dagrelayout"
	"github.com/d2lang/d2/d2themes/d2themescatalog"
	"github.com/yuin/goldmark"
)

goldmark.New(
	goldmark.WithExtensions(&d2.Extender{
		// Defaults when omitted
		Layout:  d2dagrelayout.DefaultLayout,
		ThemeID: &d2themescatalog.CoolClassics.ID,
		Sketch:  false,
	}),
).Convert(src, dst)

Every field is optional:

• Layout selects the layout engine. Defaults to d2dagrelayout.DefaultLayout.
• ThemeID selects a theme; see the d2themescatalog package for the catalog. Defaults to CoolClassics.
• Sketch renders diagrams in a hand-drawn style. Defaults to false.

Output

Each d2 block is replaced by an inline SVG wrapped in a <div class="d2">, which you can target for styling. The SVG carries its own <style>, so no additional CSS is needed.

A block that D2 cannot compile falls back to its source, HTML-escaped, in a <pre><code> inside the same wrapper. Convert still succeeds, so one bad diagram does not take down the rest of the document.

Example

The following diagram shows the important link between the letters X and Y:

```d2
x -> y
```

```d2
dogs -> cats -> mice: chase
replica 1 <-> replica 2
a -> b: To err is human, to moo bovine {
  source-arrowhead: 1
  target-arrowhead: * {
    shape: diamond
  }
}
```

Upgrading

As of D2 v0.8, D2 moved from oss.terrastruct.com/d2 to github.com/d2lang/d2. If you set Layout or ThemeID, update your own imports to match.

More Goldmark Extensions

• Katex: math and equation support through KaTeX