Plugins and Checks

Enable and configure plugins, and set how strictly the build checks links and content.

`plugins`

Key	Type	Default	Description
`enabled`	list of string	See below	List of enabled built-in plugin names. Replaces the default list entirely when set. Does not affect external plugins.
`disabled`	list of string	`[]`	Plugin names to turn off, of any type (built-in, client-side, or external). Only removes the named entries; never replaces the rest.
`config`	map	`{}`	Per-plugin configuration. Keys are plugin names, values are maps of plugin-specific options.

Default enabled list:

plugins:
  enabled:
    - search
    - seo
    - sitemap
    - robots
    - rss
    - atom
    - content_lint
    - link_validator
    - redirects
    - llms_txt
    - katex
    - mermaid
    - social_cards

plugins:
  config:
    social_cards:
      skip_if_image: true
    rss:
      limit: 20
    slideviewer:
      always: false

plugins:
  disabled:
    - social_cards
    - reading_progress

`link_validation`

Key	Type	Default	Description
`enabled`	bool	`true`	Enable the link validation pipeline.
`level`	string	`"warn"`	Default severity level. `error`, `warn`, or `ignore`.
`on_broken`	string	`"error"`	Policy for broken internal links. `error`, `warn`, or `ignore`.
`on_broken_anchor`	string	`"error"`	Policy for broken anchor references. `error`, `warn`, or `ignore`.
`report`	string	`"pretty"`	Report output format. `pretty`, `json`, or `github-actions`.
`on_relative_links`	string	`"warn"`	Policy for relative links (without leading `/`). `error`, `warn`, or `ignore`.
`on_local_links`	string	`"warn"`	Policy for `file://` or absolute local paths. `error`, `warn`, or `ignore`.
`on_unverified_internal`	string	`"warn"`	Policy for internal links that cannot be resolved to a known page. `error`, `warn`, or `ignore`.
`check_anchors`	bool	`true`	Validate anchor targets (`#id` references).
`check_images`	bool	`true`	Validate image `src` paths.
`same_site_policy`	string	`"ignore"`	Policy for absolute links pointing to the same site URL. `error`, `warn`, or `ignore`.
`site_root_escape_prefix`	string	`"site:"`	Prefix for links that bypass collection/lang/version lane logic (e.g., `site:/pricing`). Set to `""` to disable.
`exclude`	list of string	`[]`	Path patterns to exclude from validation.
`ignore`	list of string	`[]`	Additional path patterns to ignore during validation.
`fail_build`	bool	`false`	Fail the build on link validation errors.

`link_validation.external`

Key	Type	Default	Description
`check`	bool	`false`	Enable external URL checking (opt-in).
`concurrency`	int	`8`	Maximum concurrent HTTP requests. Min: 1.
`timeout`	string	`"10s"`	HTTP request timeout (Go duration format, e.g., `"10s"`, `"30s"`).
`cache`	string	`".sarde/linkcache.json"`	Path to the URL check result cache file.
`cache_ttl`	string	`"72h"`	Cache entry time-to-live (Go duration format).
`on_broken`	string	`"warn"`	Policy for broken external links. `error`, `warn`, or `ignore`.
`ignore`	list of string	`[]`	URL glob patterns to skip.
`method`	string	`"head-then-get"`	HTTP method for checking. `head-then-get` (try HEAD first, fall back to GET), `head`, or `get`.

`content_lint`

Key	Type	Default	Description
`enabled`	bool	`true`	Enable content linting.

`content_lint.rules`

Key	Type	Default	Description
`heading_max_length`	int	`60`	Maximum heading length in characters. Min: 1.
`heading_increment`	bool	`true`	Require heading levels to increment by one (no skipping from `##` to `####`).
`image_alt_required`	bool	`true`	Require alt text on all images.
`no_empty_links`	bool	`true`	Flag links with empty text.
`frontmatter_required`	list of string	`[]`	Frontmatter fields that must be present on every page (e.g., `["title", "description"]`).
`tabs_marker_syntax`	bool	`true`	Flag `:::tabs` blocks whose panels will silently collapse into one, such as `=== Label` instead of `== Label`, or a `::tab[...]` directive that does not exist.