glyphtex-engine

LaTeX → PDF in the browser and on the server. Wraps Tectonic (XeTeX + xdvipdfmx) compiled to WebAssembly.

import { TexEngine } from 'glyphtex-engine';

const engine = await TexEngine.load(fetch('/tectonic.wasm'));

// The TeX bundle: document classes, packages, fonts, and the format file.
for (const [name, bytes] of bundle) engine.addFile(name, bytes);

engine.addFile('main.tex', String.raw`
  \documentclass{article}
  \begin{document}\section{Hello}\end{document}
`);

const result = engine.compile({ entry: 'main.tex', synctex: true });

if (result.status !== 'failed') {
  const pdf = engine.pdf();          // Uint8Array
}
for (const d of result.diagnostics) {
  console.log(`${d.severity} ${d.file ?? '?'}:${d.line ?? '?'} — ${d.message}`);
}

Status is not a boolean

compile() resolves for any run that completed. status distinguishes four outcomes, and only one of them means "no output":

| status | Meaning | | --- | --- | | spotless | No warnings or errors. | | warnings | Warnings only — the overwhelmingly common case for real documents. | | errors | TeX reported errors but recovered. A PDF usually still exists. | | failed | Nothing was produced. message explains why. |

Treating errors as fatal would reject documents that TeX itself considers publishable, so check status !== 'failed' before reading the PDF.

Missing files are data, not exceptions

When the engine asks for a file that is not in the virtual filesystem, it is reported in result.missingFiles rather than being guessed at or thrown:

const result = engine.compile({ entry: 'main.tex' });
if (result.missingFiles.length) {
  for (const name of result.missingFiles) {
    engine.addFile(name, await fetchPackage(name));
  }
  // Auxiliary files are retained, so the retry picks up where it left off.
  const retry = engine.compile({ entry: 'main.tex' });
}

This is the hook for on-demand package fetching. It is deliberately not an error: a missing file is recoverable, and TeX has no graceful degradation for a wrong one — substituting a near-match font silently corrupts output or hangs the engine.

Multi-file projects

Add every file, then point entry at the root. \input, \include, and \includegraphics resolve against the same virtual filesystem.

engine.addFiles({
  'main.tex': mainSource,
  'chapters/intro.tex': introSource,
  'figures/plot.pdf': plotBytes,
  'refs.bib': bibSource
});
engine.compile({ entry: 'main.tex' });

Options

All fields are optional; omitted ones take the Rust-side defaults. See CompileOptions for the full list — it is generated from the Rust definitions, so your editor's completions are authoritative.

| Option | Default | Notes | | --- | --- | --- | | entry | main.tex | Root document. | | jobname | derived from entry | Base name for .pdf, .log, .synctex. | | maxPasses / minPasses | 4 / 1 | Reruns stop once auxiliary files stop changing. | | haltOnError | false | Matches tectonic: TeX recovers from most errors. | | synctex | false | Emit <jobname>.synctex. | | outputFormat | pdf | xdv skips xdvipdfmx and is faster. | | paper | letter | e.g. a4. | | deterministic | false | Byte-identical output across runs. | | logLevel | error | trace logs every file open — very verbose. |

Types come from Rust

The declarations in src/generated/ are produced from the Rust definitions in crates/glyphtex-tex-api by ts-rs, so they cannot drift from what the engine accepts.

pnpm generate   # regenerate after changing the Rust types

That crate has no C dependencies and does not include the engine, so this works on any machine — no Emscripten toolchain required.

Not supported in WebAssembly

These need a subprocess, which does not exist in this sandbox:

• minted — needs Python/Pygments. Use listings, which is pure TeX.
• biber — a Perl program with no wasm build. bibtex runs in-process.
• TikZ externalization — needs shell escape.

shellEscape is exposed for API parity with a native build; it has no effect here.

Tests

pnpm build
GLYPHTEX_WASM=path/to/tectonic_wasm.wasm GLYPHTEX_BUNDLE=path/to/bundle pnpm test

The suite skips itself when those are absent.