pagelet

pagelet is a deterministic, embeddable EPUB parsing and pagination engine written in Rust.

The project is built as an independent engine. Flutter, CLI, C ABI, and future WASM integrations are host adapters; EPUB parsing, document IR construction, layout, pagination, diagnostics, and cache decisions stay in Rust.

Status

pagelet is in the 0.x architecture and implementation phase:

• Rust APIs may change;
• cache schemas are not stable across minor versions;
• wire protocols are explicitly versioned;
• reflowable EPUB is the primary target;
• DRM, JavaScript execution, fixed-layout fidelity, PDF generation, and full browser CSS compatibility are not first-version goals.

Unsupported features must be reported through diagnostics or capability reports, not silently discarded.

Workspace

crates/pagelet           public Rust library crate

pagelet is the only Rust library package published to crates.io. Internal engine boundaries such as core types, document IR, EPUB parsing, text measurement, layout, engine orchestration, wire DTOs, and test helpers live as modules inside that crate until a future ADR changes the release strategy.

Quick Start

cargo check --workspace
cargo fmt --all -- --check
cargo deny check licenses

The minimum supported Rust version is declared in Cargo.toml and currently set to Rust 1.95.0. The local development toolchain is pinned by rust-toolchain.toml.

External Standards Tools

Pinned W3C EPUB Tests and EPUBCheck distributions are described by tests/corpus-manifest.toml. Download them explicitly, then keep validation offline:

cargo xtask external sync --locked
cargo xtask external verify

Artifacts default to target/pagelet-external and are not committed. Set PAGELET_EXTERNAL_ROOT when CI or a shared local cache uses another location.

Licensing

pagelet is licensed under either of:

• MIT, see LICENSE-MIT;
• Apache License 2.0, see LICENSE-APACHE.

Third-party notices are tracked in THIRD_PARTY_LICENSES.md.