Packages

Packages

Postext is published as six npm packages that share one layout. postext lays the document out; the others read the result. The monorepo also holds the Sandbox component and the website (see Project Structure).

Package	Version	What it does
postext	1.16	The layout engine, plus canvas and HTML renderers, the layout worker, .postext bundles and a React component.
postext-pdf	1.16	Print-ready and accessible PDF.
postext-epub	0.2	EPUB 3, fixed layout or reflowable.
postext-folio	0.5	A 3D book viewer on three.js.
postext-citeproc	1.16	Citations and bibliographies in CSL styles.
postext-cli	1.22	The postext command line, as one self-contained executable per system (also on each GitHub Release).
postext-sandbox	—	The Sandbox editor as a React component (used by postext.dev, not published to npm).
@postext/typescript-config	—	Shared TypeScript settings (internal).

All packages are ESM only and written in strict TypeScript. Each can also be imported from esm.sh (https://esm.sh/postext, https://esm.sh/postext-pdf, …).

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postext

The core. Enriched markdown and a configuration in, a laid-out VDTDocument out.

Entry	Contents
postext	buildDocument, the canvas renderer (renderPage, renderPageToCanvas, renderToCanvas), the HTML renderer (renderToHtml, renderToHtmlIndexed), the parser, defaults and resolvers for every configuration section, the math engine, hyphenation, warnings, outlines, bundles (re-exported) and the citation engine registry.
postext/worker	createLayoutWorker(): layout on a Web Worker with last-wins cancellation and font transfer.
postext/worker/entry	The worker script itself, for bundlers that need its URL.
postext/bundle	.postext files: openBundle, createBundle, buildBundle, font and image adapters, the zip codec and configuration migrations (migrateConfig, CONFIG_VERSION).
postext/react	createLayout(content, config): a component that shows the pages.

Dependencies: @chenglou/pretext (measurement), Hypher with TeX patterns (hyphenation), MathJax (maths, bundled and loaded on demand), gray-matter (frontmatter). Peer: react ≥ 18, used only by postext/react.

Source: packages/postext.

postext-pdf

Writes a VDTDocument, or a book's chapters, as PDF: embedded and subset fonts with kerning, HarfBuzz shaping for Arabic, vector SVG figures and PDF print masters, outlines, links, page labels, RGB/CMYK/grayscale, crop marks, and tagged PDF/UA-1 output.

Entry	Contents
postext-pdf	renderToPdf(doc, options), decompressWoff2, svgToVectorDrawing, the PdfFontProvider and warning types.
postext-pdf/worker	createPdfWorker(): the same render on a worker.
postext-pdf/worker/entry	The worker script.

Built on pdf-lib, @pdf-lib/fontkit and wawoff2 (patched in patches/ for bundlers). Peer: postext of the same major. Source: packages/postext-pdf. Guide: Generating PDFs.

postext-epub

Writes a book as EPUB 3.3, in the browser or in Node: a fixed layout (pre-paginated, every printed page with real text) or a reflowable book in semantic XHTML. Fonts, navigation, print page markers, right-to-left books and accessibility metadata; checked with EPUBCheck.

Entry	Contents
postext-epub	renderToEpub(chapters, options), readEpub (for viewers), packEpub, buildFixedPublication, buildReflowablePublication.
postext-epub/worker	createEpubWorker().
postext-epub/worker/entry	The worker script.

Peer: postext. Source: packages/postext-epub. Guide: EPUB books.

postext-folio

Shows a laid-out document, or any set of page images, as a book whose leaves curl and cast shadows in three.js. Left- and right-bound books, paper stocks, lighting, tilt; pages are painted on demand around the open spread.

Exports createFolioFromDocument, createFolio (from page images), PageFlipper, FlatPageFlipper (a flat light table), spreadsOf, paperSpec, FOLIO_CSS. Peers: postext, three ≥ 0.160. Source: packages/postext-folio. Guide: A 3D book.

postext-citeproc

Formats the citations a document writes in Pandoc syntax with citeproc-js and builds the bibliography. Bundles 19 CSL styles (APA, Chicago, Harvard, ISO 690, GB/T 7714 2015 and 2025, MLA, IEEE, Vancouver, AMA, Nature, OSCOLA…) and 12 CSL locales; any other CSL style can be passed whole.

Entry	Contents
postext-citeproc/register	Registers the engine with Postext. Import it once, or hand setCitationEngineLoader(() => import('postext-citeproc/register')) to load it only when a document cites.
postext-citeproc	createCiteprocEngine, STYLES, LOCALES, STYLE_CATALOG, parseBibtex.
postext-citeproc/catalog	The style list alone, for a picker.

The package is MIT; citeproc-js is CPAL 1.0 / AGPL 1.0 and the styles and locales are CC BY-SA 3.0 (see its THIRD_PARTY_LICENSES.md). Guide: Citations.

postext-cli

The postext command: pdf, html, epub, image, images, docx, import-docx, pack, unpack, info, check and build --watch, from a .postext bundle, a book folder or loose Markdown, with --json reports and stable exit codes for scripts and agents. Bun compiles it with the engine, the writers, Skia (@napi-rs/canvas), HarfBuzz, the ICC profiles and the default fonts into one executable per system: macOS arm64 and x64, Linux x64, arm64 and musl, Windows x64. Every release attaches them to the GitHub Release with SHA256SUMS and readme.txt; on npm, postext-cli is a launcher whose optional dependencies postext-cli-<system> carry the executables. Source: packages/postext-cli. Guide: Command Line.

postext-sandbox

The editor at postext.dev/en/sandbox as a React component (<PostextSandbox />): library of books, markdown editor, Design and Resources panels, Canvas / PDF / Folio / HTML / EPUB previews, checks and storage in IndexedDB. See Sandbox, Standalone usage.

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Versions and releases

• postext, postext-pdf, postext-citeproc and postext-cli share a version number (the command line carries the engine it was built with); postext-epub and postext-folio have their own. A companion package needs the postext it was released with, or a later one of the same major, so upgrade them together.
• Releases are automatic. Merging develop into main runs the Release workflow, which bumps every package (patch by default, minor or major from the PR label), builds and tests them, publishes them to npm, builds the command-line executables (tested on Linux, Alpine, macOS and Windows and attached to the GitHub Release) and regenerates the showcase layouts. See Development Setup.
• .postext bundles and stored configurations carry a configVersion; migrateConfig keeps books written by older releases laying out as they did.