pdfluent-lopdf

Low-level PDF document object model and writer in pure Rust.

pdfluent-lopdf is the parser, object-model, and serializer that the PDFluent commercial Rust PDF SDK uses for read/write of the underlying PDF byte structure. It is published as MIT so it can also be used standalone like any open-source library.

This crate is a fork of lopdf by Junfeng Liu, Emulator, and contributors. The fork is maintained by PDFluent and the additions are contributed back to upstream where possible.

What this crate gives you

Parsing of PDF object streams, cross-reference tables (classical + xref-stream + hybrid), and incremental updates
Typed access to PDF dictionaries, arrays, names, strings, streams, and indirect references
Serialization back to a valid PDF (including incremental update writing)
AES-256 encryption (V=5, R=6, /CFM /AESV3) — required by PDF 2.0 — added in this fork
Optional image, chrono, jiff, serde, tokio features (see Cargo.toml)

What this crate is not:

Not a renderer. See pdf-render (commercial) for rasterization.
Not a high-level facade. See pdfluent for the SDK API.
Not a content-stream interpreter. See pdf-interpret (open-source).

Install

[dependencies]
pdfluent-lopdf = "0.39"

Minimal example

use pdfluent_lopdf::Document;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let doc = Document::load("input.pdf")?;
    println!("PDF version: {}", doc.version);
    println!("Pages: {}", doc.get_pages().len());
    Ok(())
}

For higher-level operations (rendering, signing, redaction, PDF/A, extraction, forms) use the pdfluent facade — it consumes this crate as the underlying object model.

License

MIT — preserved from the upstream lopdf project.

Copyright (c) Junfeng Liu, Emulator, and lopdf contributors
Copyright (c) 2026 Innovation Trigger BV (PDFluent fork)

See LICENSE.

Why a fork

PDFluent depends on a small set of features that are either ahead of upstream or pin-controlled for the commercial release cycle:

AES-256 — PDF 2.0 mandates this for new documents; not yet in upstream
Performance pinning — coordinated exact-version pins across the PDFluent workspace prevent transitive churn for the commercial release
PDF/A round-trip — small adjustments to write determinism to support pdf-compliance validation

We aim to upstream non-PDFluent-specific improvements. This crate stays MIT to honor that path.