Fulgur¶

Your AI writes freely. Fulgur delivers with authority.

An HTML/CSS to PDF library for Rust. Seal the output your AI agent generates into authoritative, permanent documents.

Quick Start¶

CLIRustPythonRuby

cargo install fulgur-cli
fulgur render input.html -o output.pdf

# Cargo.toml
[dependencies]
fulgur = "0.5"

use fulgur::Engine;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let html = "<h1>Hello, Fulgur</h1>";
    let pdf = Engine::builder().build().render_html(html)?;
    std::fs::write("output.pdf", pdf)?;
    Ok(())
}

pip install pyfulgur

from pyfulgur import Engine

html = "<h1>Hello, Fulgur</h1>"
pdf = Engine().render_html(html)
with open("output.pdf", "wb") as f:
    f.write(pdf)

gem install fulgur

require "fulgur"

html = "<h1>Hello, Fulgur</h1>"
pdf = Fulgur::Engine.new.render_html(html)
File.binwrite("output.pdf", pdf)

Use Cases¶

AI Agent Output

Seal HTML reports generated by AI agents into authoritative, permanent PDFs.
SaaS Invoice Generation

Generate invoices and receipts dynamically from templates and JSON data in multi-tenant environments.
Batch Reports

Produce thousands of PDFs in parallel from JSON data with deterministic, reproducible output.

Features¶

Blazing Fast

Throughput that outpaces wkhtmltopdf and Puppeteer. Benchmarked, not just claimed.
Pure Rust

No headless browser, no Chromium, no C++ runtime. A single cargo add fulgur.
Offline-First

Zero network access at render time. Every asset is explicitly bundled — perfect for sandboxed and WASM environments.
Deterministic Output

Same HTML + same bundled assets = byte-identical PDF, reproducible across machines.
CSS Paged Media (GCPM)

Running headers/footers, page counters, named pages, and margin boxes — the CSS spec that matters for real documents.

Comparison¶

	Fulgur	wkhtmltopdf	WeasyPrint	fullbleed	Puppeteer	Prince	Gotenberg
Pure Rust	✅	❌	❌	✅	❌	❌	❌
WASM support	planned	❌	❌	❌	❌	❌	❌
CSS GCPM depth	★★★	★★	★★★	★	★★	★★★★	★★
No headless browser	✅	❌	✅	✅	❌	✅	❌
JavaScript execution	❌	△	❌	❌	✅	✅	✅
Serverless-friendly	✅	✅	✅	✅	△	△	△
Speed	⚡⚡⚡	⚡	⚡	⚡⚡⚡	⚡	⚡⚡	⚡
License	MIT/Apache	LGPL	BSD	MIT	MIT	Commercial	MIT
Install size	small	medium	medium	small	large	medium	large

Prince is the reference implementation for CSS Paged Media and the closest benchmark for CSS coverage. Gotenberg requires Docker. Puppeteer and Gotenberg bundle a full Chromium installation.

Standing on the Shoulders of wkhtmltopdf¶

Fulgur was inspired by wkhtmltopdf — a tool that served the web development community for over a decade. We built Fulgur to carry that legacy forward in the Rust era: faster, safer, and ready for the age of AI-generated documents.

MIT / Apache-2.0 · GitHub · crates.io