API

renderToBuffer(element, options?): Promise<Uint8Array>   // the PDF bytes
renderToFile(element, path, options?): Promise<void>      // renders, then writes the file
renderToStream(element, options?): Promise<Readable>     // the PDF as a Node stream

renderToStream returns a stream to pipe into an HTTP response: (await renderToStream(<Invoice />)).pipe(res). The stream starts once the PDF is ready, and a failed render rejects the promise.

All three take the same options:

A bad option fails the render with ENGINE_REJECTED at its path (options.threads, options.remoteImages.timeoutMs): a creationDate that is not RFC 3339, a threads that is not an integer from 1 to 256, or a timeout or maxBytes that is not a number from 0 (NaN, a negative number, a string), or an option of the wrong type (threads: '4', localImages without root). A fractional timeout is rounded up to a whole millisecond.

Font.register({ family, src }) adds a font family, from a path, a URL or bytes. See Fonts.

Font.registerHyphenationCallback(fn) splits words for hyphenation with your own function; null removes it. See Text: hyphenation and direction.

StyleSheet.create(styles) returns the styles unchanged, with their types.

init() loads Tailwind's compiler (when @inkoxide/tailwind is installed), the engine and the fonts. The first render does it anyway; call it at server startup so the first request does not wait (about 160 ms). It resolves to the same status as engineStatus().

Health checks. version() returns { engine, schema, gitSha }: the engine's version, the document schema version it reads and the commit it was built from. engineStatus() returns undefined until the engine has started (the first init or render), then { version, fonts, hyphenation, warnings }: the font ids registered, which hyphenation languages loaded ({ en: true }), and start-up warnings such as a missing bundled font.

app.get('/health', (_req, res) => {
  const status = engineStatus();
  res.status(status ? 200 : 503).json(status ?? { starting: true });
});

countPages(pdf) is the page count of a PDF made by renderToBuffer. It reads the page tree the engine writes, so it is not a general PDF parser.

Types. The props of a component are exported as a type named after it (DocumentProps, TextProps, TextFieldProps, FieldProps, SvgProps, MarkerProps, TspanProps, CanvasProps and so on); PolyProps serves Polyline and Polygon, GradientProps both gradients, SvgPresentation the attributes every SVG shape takes, and SvgTextProps the props of a Text in an Svg. Also exported:

• styles and values: Style, StyleProp, AbsoluteLength, Length, LengthPercent, LengthAuto, PageSize, PagePreset, BreakProp, BookmarkProp, FontWeightName, Permissions (of <Document permissions>), and TextFormat, the format of a TextField;
• render props and images: RenderProp, PageInfo, ImageSrc, ImageSrcValue, ImageRequest, Painter, the painter a Canvas draws with, CanvasGradient, its gradients, and CanvasTextOptions, the options of its text;
• options and results: RenderToBufferOptions, LocalImageOptions, RemoteImageOptions, FontRegistration, FontSource, FontSrc, EmojiSource, FontWeight, HyphenationCallback, EngineStatus, EngineVersion, RenderErrorCode and DataIssue.

Concurrency. A render runs on Node's thread pool, so many can run at once. threads sets how many cores one render uses; with threads: 1 each render stays on its own pool thread. Node's UV_THREADPOOL_SIZE (default 4) caps how many renders run at the same time.