Markdown directives

Directives let .md pages opt into typed Foldkit islands while remaining valid portable Markdown.

Block directive

:::note{tone="info"}
This content is validated before it reaches the renderer.
:::

Schema validation

Define the allowed directive names and attributes in the Markdown island registry. Unknown directives, invalid attributes, and unsafe URLs fail during compilation with a source location.

Choose directives or MDX

Use directives for a small vocabulary shared with non-MDX tooling. Use .mdx when nested component composition is clearer. Both paths produce the same typed Foldocs AST and static output.