# Honzo
[](https://github.com/Nisoku/Honzo/actions/workflows/lint.yml)
[](https://crates.io/crates/honzo-core)
[](https://www.npmjs.com/package/@nisoku/honzo)
[](LICENSE)
---
The "ideal" ebook format.
Honzo is a binary ebook format designed for simplicity, performance, and portability. Zero-copy parsing, pull-based streaming, per-chunk compression, and portable annotations that travel with the file.
## Features
| **Zero-copy parsing** | Read without allocating. Embeddable on bare metal. |
| **Pull-based streaming** | Decompress chapters on demand. Never hold the whole book in memory. |
| **Per-chunk compression** | LZ4 per chapter via TOC flag. Images and fonts store raw. |
| **Separately editable tail** | META is last. Edit title, tags, revision without touching DATA. |
| **Portable annotations** | Highlights, bookmarks, notes stored in the file via EXTRA section. |
| **Search index** | Inverted term index as SIDX chunk (MessagePack). |
| **Encryption envelope** | AES-256-GCM per-chunk encryption with X25519 ECDH key exchange. |
| **Multi-language metadata** | Titles and descriptions localized per BCP 47 language tag. |
| **Format conversion** | Import from EPUB, MOBI, PDF; embedded WASM converter for browsers. |
## Quick Start
### Rust
```rust
use honzo_core::HonzoParser;
use honzo_io::{HonzoBuilder, HonzoStream};
// Zero-copy parse
let data = std::fs::read("book.hzo").unwrap();
let p = HonzoParser::new(&data, 1).unwrap();
println!("{} chunks", p.head().chunk_count);
for entry in p.toc_entries() {
println!(" {} - {:?}", entry.chunk_id,
std::str::from_utf8(&entry.chunk_type));
}
// Streaming read
let file = std::fs::File::open("book.hzo").unwrap();
let mut stream = HonzoStream::open(file, 1).unwrap();
for chapter in stream.chapters() {
let text = chapter.unwrap();
println!("Chapter: {} bytes", text.len());
}
// Build
let hzo = HonzoBuilder::new()
.add_chunk(*b"CHAP", b"Hello, world!", Compression::None,
MarkupType::Markdown, CoverType::Front, None, None, None)
.finalize()
.unwrap();
```
### TypeScript
```typescript
import { createReader, buildHonzo } from '@nisoku/honzo';
const response = await fetch('book.hzo');
const buf = new Uint8Array(await response.arrayBuffer());
const reader = await createReader(buf);
console.log(reader.chunkCount, reader.layoutMode);
const meta = reader.getMeta();
console.log(meta.title?.en);
```
### C
```c
#include "honzo.h"
HonzoHandle* handle = HonzoHandle_parse(data, data_len, 1);
uint32_t count = HonzoHandle_chunk_count(handle);
```
## Repository Layout
```txt
Honzo/
Cargo.toml # Rust workspace root
honzo.ksy # Kaitai Struct binary spec
Build/
crates/
honzo-core/ # no_std wire-format parser
honzo-chunks/ # Chunk types, validation, search index
honzo-io/ # Builder, reader, stream, DRM (std)
honzo-convert/ # EPUB/MOBI/PDF/CBZ import
honzo-c/ # C FFI bindings (Diplomat)
honzo-wasm/ # WASM bindings
honzo-cli/ # CLI binary
honzo-fixtures/ # Test fixture generator
adapters/typescript/ # npm @nisoku/honzo
Demo/ # Vite web demo (reader, maker, inspect, convert)
Docs/ # Documentation site (docmd)
Tests/ # Integration tests
```
## Documentation
- [Getting Started](https://nisoku.org/Honzo/getting-started/quickstart/)
- [Format Specification](honzo.ksy)
- [API Reference](https://nisoku.org/Honzo/api/)
- [Live Demo](https://nisoku.org/Honzo/demo/)
## Packages
| Rust (core) | `honzo-core` | [crates.io](https://crates.io/crates/honzo-core) |
| Rust (chunks) | `honzo-chunks` | [crates.io](https://crates.io/crates/honzo-chunks) |
| Rust (io) | `honzo-io` | [crates.io](https://crates.io/crates/honzo-io) |
| Rust (convert) | `honzo-convert` | [crates.io](https://crates.io/crates/honzo-convert) |
| Rust (CLI) | `honzo-cli` | [crates.io](https://crates.io/crates/honzo-cli) |
| TypeScript / WASM | `@nisoku/honzo` | [npm](https://www.npmjs.com/package/@nisoku/honzo) |
| C | `honzo-c` | Source in [`Build/crates/honzo-c`](Build/crates/honzo-c) |
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md).
## License
Apache License 2.0. See [LICENSE](LICENSE).