The public package has a browser-side snapshot layer and a Zig WebAssembly renderer.
Pipeline stages
- The TypeScript wrapper accepts a string, mounted element, or ref-shaped value.
- The browser snapshot resolves DOM state, supported CSS, resources, links, SVG, and canvas policy.
- The snapshot sends self-contained HTML and typed page data to WebAssembly.
- Zig parses HTML and CSS into its internal document and box structures.
- Layout and pagination create page fragments.
- Paint commands retain supported text, links, images, and vector graphics.
- The PDF writer returns bytes, a page count, and structured diagnostics.
Snapshot boundary
Mounted input can capture computed styles, form values, pseudo-elements, canvas pixels, and open Shadow DOM. String input runs in an inert document and needs explicit resource handling for external stylesheets.
The snapshot is also where browser-only concerns live. These include alternate media, viewport selection, URL resolution, and chart canvas adapters.
Document profile and web profile
The document CSS profile is the default. The web and strict profiles enable the broader layout path. strict also changes the default unsupported CSS policy to error.
Result ownership
WebAssembly returns bytes to the TypeScript wrapper. PdfDocument exposes defensive copies and owns previews and object URLs created through it.
The reusable renderer has a longer lifetime. It owns the Worker or main-thread WebAssembly context and registered fonts.