D2: Declarative Diagramming

D2: Declarative Diagramming is a Diagrams as Code tool that converts code into diagrams. Check out their Cheat Sheet to learn more.

Example

The following d2 markdown code block:

direction: right
x -> y -> z: hello

will produce the diagram:

Enabling D2

When you choose D2 as an option, two things are added to the Starlight project:

1. Astro D2 plugin is added as an Astro integration.
2. VITE_D2_GENERATE environment setting is configured which controls whether the d2 command will be called to create diagrams from d2 markdown code blocks.
   • false is the default value and appropriate for CI builds
   • true is an appropriate value for a local .env file since developers will generate diagrams only when building locally

Note that the d2 command must be installed for local development.