streamdown@2.6.0

Minor Changes

• 49bd143: fix(animate): serialize streaming animation across blocks

  Word stagger now runs on a shared wall-clock timeline so sibling sections no longer fade in on top of each other during streaming. Related cleanup: trailing spaces stay inside animated spans (no early link underlines), animate wrappers drop when streaming ends, already-seen text stays steady under StrictMode, and un-animated streaming is no longer deferred behind a starvable transition.

  Inspired by #493, #531, and #536.

  Fixes #482
  Fixes #535
  Fixes #550
  Fixes #570

• b734cbf: - Add custom download filenames for code, table, and mermaid via the controls prop

  • Configure downloads with download: { filename: "customName" } while keeping boolean true/false to show or hide
  • Preserve automatic file-extension mapping based on language or export format
  • Remove the codeDownload prop in favor of the unified controls API

• 5faa6fa: Add codeBlockMaxHeight and tableMaxHeight props with streaming auto-scroll

• 4436b56: - Add controls.table.csvSeparator ("," | ";" | "\t" | "auto") for table copy and download CSV

  • Reuse tableDataToCSV separator handling, including locale-aware "auto" mode
  • Improve CSV escaping to respect the selected separator for Excel compatibility

Patch Changes

• 6ec3c48: fix(animate): animate inline code during streaming

  Skip the animate visitor on pre (and svg/math/annotation) only — not bare code. Fenced/highlighted blocks stay un-split via their pre ancestor; inline backtick spans now get the same per-word fade-in as surrounding prose.

  Fixes #594

• 725e390: Forward rest props through block code. The code component spread its rest props on the inline branch and dropped them on the block branch, so an attribute a consumer put on a fenced code element never reached the DOM. CodeBlockBody now takes part in that comparison, so a forwarded attribute updates instead of keeping the value it first rendered with.

• 7e82400: Fix dir="auto" in static mode to detect text direction per semantic block (instead of once for the whole document), keep code LTR, and use content-majority direction for mixed-script prose.

• fb5d7b9: Serialize Mermaid SVGs before download so HTML-style tags render as valid SVG markup.

• fe38e75: Added accessibility improvements for code block controls by adding aria labels to copy/download buttons and announcing copy success state for screen readers.

• b25dbdb: fix(custom-tags): render Markdown inside custom tags with multiline content

  Adds a preprocessing step (preprocessCustomTags) that normalizes multiline
  custom tags into a blank-line-sandwiched HTML block so CommonMark interrupts
  the raw-HTML block and parses the nested content as Markdown, with
  parseMarkdownIntoBlocks re-merging the interrupted open/content/close tokens
  so streaming still treats the whole custom tag as one block. Previously, when a
  custom tag contained multiline content (e.g. <ai-thinking> **bold**</ai-thinking>), CommonMark treated the block as raw HTML, stripping
  Markdown formatting. Tags listed in literalTagContent are excluded from
  re-parsing.

  Closes #478

• 26a8440: Fix doubled user-content- prefix on footnote ids

  Footnote list items were rendered with id="user-content-user-content-fn-1" because both remark-rehype and rehype-sanitize default their clobberPrefix to user-content-, so the prefix was applied twice. Disabled clobberPrefix on rehype-sanitize so remark-rehype remains the single, consistent prefixer of both footnote ids and backref hrefs — restoring working footnote navigation.

• f7d1fb5: fix(table): add data-streamdown="table-wrapper" to fullscreen portal so copy/download dropdowns can find the table

• f0a726b: Add aria-hidden="true" to decorative SVG icon components so screen readers rely on parent button labels instead of unlabeled icons.

• 2ed2faa: Allow remend's streamdown: incomplete-link sentinel through the default sanitize schema so streamed incomplete links render as pending instead of harden [blocked].

• 8fffa9d: Render the link safety modal through a portal to document.body so it is no longer nested inside the paragraph's <p> element. This fixes the React hydration error "In HTML, <div> cannot be a descendant of <p>" that occurred when a link with link safety enabled appeared inside a paragraph.

• 2733922: fix(mermaid): add aria-hidden to decorative SVG icons in mermaid toolbar buttons

  Mermaid toolbar buttons (download, fullscreen, pan/zoom controls) already have
  accessible titles/labels, but the inline SVG icons were exposed to the accessibility
  tree causing "Content with images must be labeled" warnings. Added aria-hidden={true}
  to all decorative icon elements in download-button, fullscreen-button, and pan-zoom
  components.

  Fixes #485

• 8d36719: fix(deps): remove mermaid as a hard runtime dependency

  This patch replaces the type import with a local structural type for MermaidConfig so no type-level coupling to the mermaid package remains in the distributed typings. Users who want fully-typed mermaid config can still import type { MermaidConfig } from 'mermaid' themselves; the structural type is compatible.

  Fixes #501

• ea02609: Fix: shikiTheme prop priority chain is now fully reachable.

  Previously, shikiTheme had a default value in the props destructuring (= defaultShikiTheme), making the plugins?.code?.getThemes() fallback unreachable in both orderings. The fix removes the destructuring default and moves it to the end of the nullish coalescing chain, so all three levels are reachable:

  1. Explicit shikiTheme prop (highest priority)
  2. Code plugin's getThemes() (second priority)
  3. Built-in defaultShikiTheme (final fallback)

• 9813dd6: Fix type declarations requiring a shiki install.

  BundledLanguage, BundledTheme, and ThemeRegistrationAny are now defined locally and re-exported from streamdown, so consumers can type-check without installing shiki. Runtime highlighting remains in @streamdown/code, which still depends on shiki.

• d893759: Fix mermaid fullscreen overlay accessibility and add stable selector

  • Add data-streamdown="mermaid-fullscreen" to fullscreen overlay for stable CSS targeting
  • Update fullscreen overlay semantics to match table fullscreen behavior
  • Change role from button to dialog
  • Add aria-modal="true" for correct screen reader modal behavior
  • Improve accessibility consistency between mermaid and table fullscreen overlays

• 79c8575: fix issue with list markers, task-list checkboxes, images, and hr animations

• a1a7142: feat: add image control options (controls.image) to disable hover overlay and download button on images

  Add image to the controls prop, matching existing code, table, and mermaid patterns:

  • controls={{ image: false }} hides the hover overlay and download button
  • controls={{ image: { download: false } }} keeps the hover overlay but hides the download button

• b250038: Fix accessibility warnings for Mermaid toolbar icon buttons:

  • Add aria-hidden="true" to all decorative SVG icons to hide them from screen readers
  • Add aria-label attributes to all icon-only buttons for proper screen reader announcements
  • Add translation keys (zoomIn, zoomOut, resetView) for zoom controls

• 89c6877: Re-render memoized markdown components when their rendered output changes. The comparators compared source position, so a replacement of the same length — occupying the same lines and columns — was treated as unchanged and the component kept rendering the previous text.

• e7bdf57: fix(mermaid): render the download and copy controls inside the Mermaid fullscreen portal so they're reachable when the diagram is expanded

• 8f02c09: Fix table copy and download actions not working in fullscreen mode.

  • Support table lookup inside the fullscreen portal container.
  • Restore copy and download functionality for fullscreen tables.
  • Keep existing inline table controls behavior unchanged.

• f46cd3c: - Fixed table copy losing line breaks inside cells containing <br> elements.

  • Preserved multiline content during table data extraction.
  • Improved copied Markdown, CSV, and TSV output consistency for multiline cells.
  • Added coverage for <br> handling in table extraction.

• dc3f1d2: - Fix code block line wrapping when line numbers are disabled.

  • Ensure code block lines are rendered as block elements regardless of the lineNumbers setting.
  • Prevent multiple code lines from collapsing into a single visual line when lineNumbers={false}.

• Updated dependencies [a99d675]

• Updated dependencies [9f96409]

• Updated dependencies [8093f2a]

• Updated dependencies [57c3089]

  • remend@1.3.1

remend@1.3.1

Patch Changes

• a99d675: Fix crash on iOS 16.0-16.2 / Safari < 16.3 by removing the lookbehind assertion from the single-tilde escape pattern (#519).

  JSCore on those versions doesn't support lookbehind ((?<=...)) and throws a SyntaxError while the module is being evaluated, before any user code runs, so there is no way to catch it. The preceding word character is now captured and written back in the replacement instead.

• 9f96409: Preserve complete italic emphasis when a closing asterisk is followed by word text.

• 8093f2a: Treat LaTeX paren and bracket math as protected math contexts during emphasis completion.

• 57c3089: Fix quadratic code-block scanning. isInsideCodeBlock now builds a linear-time position lookup (cached per text) instead of rescanning the whole prefix on every call, so handlers that probe many positions no longer degrade quadratically. Repairing an unclosed, bracket-heavy 58k-character code block drops from ~915ms to ~0.4ms per call.

streamdown@2.5.0

Minor Changes

• d6666b6: Add lineNumbers prop to disable line numbers in code blocks
• d4ec6c0: Add meta prop to CustomRendererProps. Custom renderers now receive the raw metastring from the code fence (everything after the language identifier, e.g. ```rust {1} title="foo" → meta = '{1} title="foo"'). The prop is optional (meta?: string) and is undefined when no metastring is present. Existing custom renderers are unaffected.

Patch Changes

• ac8d839: Add staggered animation-delay to streaming word/character animations so new content cascades in sequentially instead of all animating simultaneously. Configurable via the new stagger option (default 40ms). Set stagger: 0 to restore the previous behavior.

• add5374: Enable horizontal scrolling on code blocks so long lines are accessible instead of being clipped by overflow-hidden.

• 75845c0: Fix unnecessary re-renders of code blocks during streaming updates.

  Problem: In streaming mode, when new content arrives (e.g. a paragraph is appended), completed code blocks that haven't changed were still re-rendering. This happened because the Streamdown component used inline object literals as default parameter values for linkSafety ({ enabled: true }). Every time children changed and Streamdown re-rendered, these inline defaults created new references, which caused the contextValue useMemo to recompute a new StreamdownContext object. Since React propagates context changes through memo boundaries, any context consumer inside a memoized Block (such as CodeBlock) would re-render even though the block's own props were unchanged.

  Fix: Extract the inline default values for linkSafety into module-level constants (defaultLinkSafetyConfig). This ensures referential stability across renders, so contextValue only recomputes when the actual values change — not just because children updated.

• 8b1c262: fix: prepend UTF-8 BOM to CSV downloads for Excel compatibility

  • save() now prepends \uFEFF for text/csv string content so Excel on
    Windows detects UTF-8 encoding instead of falling back to ANSI.
  • TableDownloadButton refactored to use save() instead of inline Blob
    creation, ensuring the public API also gets the BOM fix.

• b105c64: Fix custom tag content being prematurely split when content follows the opening tag on the same line and contains double newlines (\n\n). The preprocessor now ensures proper HTML block structure so the parser treats the entire tag as a single unit.

• 9e6f991: Increase dropdown z-index for table copy and download menus to prevent clipping by surrounding elements.

• 9c18748: docs: document required CSS custom properties (shadcn/ui design tokens) in README

• 7b62e9a: Replace Tailwind v4-only *:last: and *:first: variant syntax with [&>*:last-child]: and [&>*:first-child]: arbitrary variants for compatibility with both Tailwind CSS v3 and v4. Fixes caret rendering on every line instead of only the last child in v3.

• Updated dependencies [e50b0c4]

• Updated dependencies [716a5f0]

  • remend@1.3.0

remend@1.3.0

Minor Changes

• e50b0c4: Add opt-in inline KaTeX completion ($formula → $formula$) via a new inlineKatex option that defaults to false to avoid ambiguity with currency symbols. Also fixes block KaTeX completion when streaming produces a partial closing $.
• 716a5f0: Escape single ~ between word characters to prevent false strikethrough rendering (e.g. 20~25°C no longer renders as strikethrough). Adds a new singleTilde option (enabled by default) that can be disabled via { singleTilde: false }.

@streamdown/code@1.1.1

Patch Changes

• 651873d: Fall back to plain text highlighting when the code block language identifier is unknown or truncated mid-stream, preventing Shiki from throwing on unsupported language names.

@streamdown/cjk@1.0.3

Patch Changes

• 6f1ea07: Updated remark-cjk-friendly and remark-cjk-friendly-gfm-strikethrough from v1.x to v2.x. The only breaking change in v2.0.0 is dropping Node.js 16 support, which Streamdown has already dropped (requires Node.js ≥18), so there is no actual impact. The actual code is identical to the latest v1.x release (v2.0.1 only added the ability to import package.json).

streamdown@2.4.0

Minor Changes

• 5edff75: Clarified Tailwind @source configuration for Streamdown and optional plugins.
  Updated documentation to keep the global @source for core streamdown only, move plugin @source guidance to plugin docs with examples, and add a caveat to include plugin entries only if installed.

• 57cd3b5: Add support for custom starting line numbers in code blocks via the startLine meta option.

  Code blocks can now specify a starting line number in the meta string:

  ```js startLine=10
  const x = 1;
  ```

  This renders line numbers beginning at 10 instead of the default 1. The feature works by parsing the startLine=N value from the fenced-code meta string and applying counter-reset: line N-1 to the <code> element.

• 57cd3b5: Add support for customizing icons via the icons prop on <Streamdown>.

  Users can override any subset of the built-in icons (copy, download, zoom, etc.) by passing a Partial<IconMap>:

  import { Streamdown, type IconMap } from "streamdown";
  
  <Streamdown icons={{ CheckIcon: MyCheckIcon }}>{content}</Streamdown>;

  Unspecified icons fall back to defaults.

• 01d27e9: Add support for custom Shiki themes via a themes option on createCodePlugin, accepting a [light, dark] pair of bundled theme names or full theme registration objects.

• 2cf559d: Add a virtual inlineCode key to the components prop, allowing inline code spans to be styled independently from fenced code blocks without manually detecting block vs. inline context.

• 27c7b03: Export table action components (TableCopyDropdown, TableDownloadButton, TableDownloadDropdown) and utilities (extractTableDataFromElement, tableDataToCSV, tableDataToTSV, tableDataToMarkdown, escapeMarkdownTableCell, TableData), enabling custom table overrides to preserve copy/download interactivity.

• fb76275: Add a fullscreen overlay for tables with Escape/backdrop-click to close and scroll locking, controlled via controls.table.fullscreen. Copy and download controls remain available in the fullscreen view.

• b392fbe: Add literalTagContent prop that accepts an array of custom HTML tag names (e.g. ['mention']) whose children should be treated as plain text, escaping markdown metacharacters so user-supplied labels aren't interpreted as formatting.

• c4c86fa: Add a dir prop that accepts "ltr", "rtl", or "auto". When set to "auto", each block's text direction is detected by scanning for the first strong Unicode character (Arabic, Hebrew, Thaana, etc.).

• 00872f0: Add a prefix prop that prepends a namespace to all generated Tailwind utility classes (e.g. flex becomes tw:flex), enabling Tailwind v4's prefix() feature for projects that need to avoid class name collisions.

• 401b901: Add support for custom renderers via plugins.renderers, allowing fenced code blocks with specific languages to be rendered by a custom component instead of the default CodeBlock.

Patch Changes

• f398611: Add onAnimationStart and onAnimationEnd callback props that fire when streaming animation begins and completes, useful for coordinating UI state with the animation lifecycle.

• f2a7e51: Fix empty lines in syntax-highlighted code blocks collapsing into nothing by rendering a newline character for empty token rows, preserving whitespace when copying.

• 9ba8511: fix: prevent ordered list animation retrigger during streaming

  When streaming content contains multiple ordered (or unordered) lists,
  the Marked lexer merges them into a single block. As each new item appears
  the block is re-processed through the rehype pipeline, re-creating all
  data-sd-animate spans. This caused already-visible characters to re-run
  their CSS entry animation.

  Two changes address the root cause:

  1. Per-block prevContentLength tracking – each Block component
     now keeps a useRef with the content length from its previous render.
     Before each render the animatePlugin.setPrevContentLength(n) method is
     called so the rehype plugin can detect which text-node positions were
     already rendered. Characters whose cumulative hast-text offset falls below
     the previous raw-content length receive --sd-duration:0ms, making them
     appear in their final state instantly rather than re-animating.

  2. Stable animatePlugin reference – the animatePlugin useMemo
     now uses value-based dependency comparison instead of reference equality
     for the animated option object. This prevents the plugin from being
     recreated on every parent re-render when the user passes an inline object
     literal (e.g. animated={{ animation: 'fadeIn' }}). A stable reference
     is required because the rehype processor cache uses the function name as
     its key and always returns the first cached closure; only the original
     config object is ever read by the processor.

• 781178b: Add a granular controls prop that accepts a boolean to toggle all controls or an object with per-feature flags (code, table, mermaid) for fine-grained control over copy, download, fullscreen, and pan/zoom buttons.

• e129f09: Add a translations prop for overriding all user-facing UI strings (copy/download button labels, modal text, image alt text, etc.), enabling full i18n support.

• Updated dependencies [a725579]

  • remend@1.2.2

remend@1.2.2

Patch Changes

• a725579: Fix emphasis completion handlers incorrectly closing bold/italic/strikethrough markers that appear inside complete inline code spans (e.g. `**bold` no longer gets a stray ** appended outside the backticks).

@streamdown/code@1.1.0

Minor Changes

• 01d27e9: Add support for custom Shiki themes via a themes option on createCodePlugin, accepting a [light, dark] pair of bundled theme names or full theme registration objects.

streamdown@2.3.0

Minor Changes

• 3657e42: Add useIsCodeFenceIncomplete hook for detecting incomplete code fences during streaming

  Custom components can now detect when the code fence in their block is still being streamed. This is useful for deferring expensive renders (syntax highlighting, Mermaid diagrams) until the code block is complete.

  import { useIsCodeFenceIncomplete } from "streamdown";
  
  const MyCodeBlock = ({ children }) => {
    const isIncomplete = useIsCodeFenceIncomplete();
  
    if (isIncomplete) {
      return <div>Loading code...</div>;
    }
  
    return (
      <pre>
        <code>{children}</code>
      </pre>
    );
  };

  The hook returns true when:

  • Streaming is active (isAnimating={true})
  • The component is in the last block being streamed
  • That block has an unclosed code fence

  The default code block component now uses this hook to set a data-incomplete attribute when incomplete, enabling CSS-based loading states.

• 32fb079: fix: hide download button on broken images and display a custom "Image not available" message instead

• d73d7bb: Make the action buttons in code block header sticky.
  Ensures copy buttons remain accessible for long code blocks.
  Improves usability when viewing large snippets.

• 15645da: Move code block lazy loading to the highlighting layer so block shells render immediately with plain text content before syntax colors resolve. This improves visual stability and removes the spinner fallback for standard code blocks.

Patch Changes

• 0987479: fix: codeblock highlight flicker while streaming
• 5d438ca: Add support for copying table data as Markdown in TableCopyDropdown.
  Introduces a Markdown copy option alongside existing formats.
  Allows users to quickly copy tables in valid Markdown format.
• ce9b4c2: Fix syntax highlighting
• ba03332: Redesign Mermaid diagram
• 6e91867: fix nested same-tag HTML block parsing in parseMarkdownIntoBlocks
• 7f9127b: Add normalizeHtmlIndentation prop to prevent indented HTML tags from being treated as code blocks
• fdef60d: Bump rehype-harden to fix "can't access property "type", node is undefined"
• 1abbf1e: Redesign table
• fb9f97c: handle custom tags with blank lines in content
• Updated dependencies [6374fbf]
  • remend@1.2.1