Extensions

Every built-in extension is available through a separate package entry.

Callouts

Import from @tanstack/markdown/extensions/callouts.

calloutsExtension

function calloutsExtension(): MarkdownExtension

Creates the block parser for GitHub-style > [!KIND] Optional title callouts.

parseCalloutBlock

function parseCalloutBlock(
  context: BlockParseContext,
): CalloutNode | undefined

Low-level parser used by calloutsExtension.

Comment components

Import from @tanstack/markdown/extensions/comment-components.

CommentComponentOptions

Provides an optional transformComponent(node) callback that receives each parsed ComponentNode.

ComponentComment

Parsed comment data with block, lowercase name, and string attributes.

commentComponentsExtension

function commentComponentsExtension(
  options?: CommentComponentOptions,
): MarkdownExtension

Parses single <!-- ::name --> comments and paired <!-- ::start:name --> / <!-- ::end:name --> blocks.

parseCommentComponentBlock

Parses a component at the current block context and optionally transforms it.

parseComponentComment

function parseComponentComment(
  line: string,
): ComponentComment | undefined

Parses one component start or single-component comment.

parseAttributes

function parseAttributes(value: string): Record<string, string>

Parses quoted, unquoted, and boolean-style attributes. A valueless attribute becomes the string "true".

Docs preset

Import from @tanstack/markdown/extensions/docs.

DocsMarkdownOptions

Contains collectHeadings?: boolean | HeadingCollectionOptions.

docsMarkdownExtensions

function docsMarkdownExtensions(
  options?: DocsMarkdownOptions,
): MarkdownExtension[]

Returns callouts, transformed comment components, and heading collection unless collection is disabled.

transformDocsComponent

Routes tabs and framework component nodes to their built-in transforms and returns other nodes unchanged.

Framework transform

Import from @tanstack/markdown/extensions/framework.

transformFrameworkComponent

function transformFrameworkComponent(
  node: ComponentNode,
): ComponentNode

Splits level-one framework sections into md-framework-panel children, records available-framework and code-block metadata, and labels nested headings by framework.

Heading collection

Import from @tanstack/markdown/extensions/headings.

HeadingCollectionOptions

Contains skipComponentNames?: ReadonlySet<string> | string[]. The default skips headings inside tabs components.

headingCollectionExtension

function headingCollectionExtension(
  options?: HeadingCollectionOptions,
): MarkdownExtension

Creates a document transform that writes collected headings to document.headings.

collectMarkdownHeadings

function collectMarkdownHeadings(
  document: MarkdownDocument,
  options?: HeadingCollectionOptions,
): MarkdownHeading[]

Collects headings recursively through lists, blockquotes, callouts, and components while respecting skipped component names and framework labels.

Streaming

Import from @tanstack/markdown/extensions/streaming.

streamingMarkdownExtension

function streamingMarkdownExtension(): MarkdownExtension

Creates a document transform for accumulated AI responses. The transform removes an empty trailing heading, blockquote, or list item that is likely to be an incomplete block marker. All completed content keeps the core parser's normal output.

Tab transforms

Import from @tanstack/markdown/extensions/tabs.

transformTabsComponent

Dispatches by the component’s variant attribute. Unknown or missing variants use heading-based tabs.

transformFileTabs

Turns code-block children into md-tab-panel elements and records file names, languages, and code in data properties.

transformPackageManagerTabs

Parses shared package... lines and framework: package... lines and records package groups plus install, dev-install, or local-install mode. A framework prefix is a name of letters, digits, _, or - followed by a colon that is not directly followed by / or ., so URL and path specifiers such as https:// and file:../ stay shared. Each line becomes a separate command group. Unprefixed groups appear under the empty string key in packagesByFramework and are also included in each named framework's groups, preserving source order.

transformBundlerTabs

Selects Vite and Rsbuild heading sections and converts them to panels.

transformHeadingTabs

Splits content at the shallowest heading depth, creates stable tab slugs, and emits one panel per section.

The transforms return the original node when their expected input structure is absent.