epub

An EPUB parsing and generation library built around io.ReaderAt and io.Writer.

Features

• Filesystem-independent: Decode takes io.ReaderAt plus archive size
• Fail-fast: returns DecodeError immediately on structural violations
• Memory efficient: on-demand stream access via Asset.Open
• Strict validation: EBPAJ/KADOKAWA-style naming and directory checks
• Fixed-layout image pages: SVG wrappers preserve page-fit across reading systems
• Structural semantics: cover, table of contents, bodymatter, index, and glossary landmarks

Quick Start

Install:

go get github.com/publira/epub

f, err := os.Open("book.epub")
if err != nil {
	log.Fatal(err)
}
defer f.Close()

st, err := f.Stat()
if err != nil {
	log.Fatal(err)
}

doc, err := epub.Decode(f, st.Size(), epub.WithCompliance(epub.LevelEBPAJ))
if err != nil {
	log.Fatal(err)
}

out, err := os.Create("out.epub")
if err != nil {
	log.Fatal(err)
}
defer out.Close()

if err := epub.Encode(out, doc); err != nil {
	log.Fatal(err)
}

For full API details and examples, see:

• https://pkg.go.dev/github.com/publira/epub

Demo CLI

The CLI lives under cmd/epub and has its own documentation:

• cmd/epub/README.md

Quick build:

go build -o ./bin/epub ./cmd/epub

EPUB specification validation

Validate a generated publication with the official W3C EPUBCheck tool:

./scripts/run-epubcheck.sh path/to/book.epub

The script requires Java 11 or newer and caches EPUBCheck under .tools/. The development container includes Temurin Java 25.0.4.

License

Apache License 2.0