Yuedu Reader

A native iOS reader powered by CoreText.
EPUB / TXT / Markdown / RSS / Manga / OPDS / WebDAV / TTS / CJK vertical writing.

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Features · Screenshots · Downloads · Getting Started · Troubleshooting · Contributing · License

Yuedu Reader is an iOS-first reading app for serious long-form reading. It focuses on native typography, CJK vertical writing, local libraries, manga, RSS, web article normalization, TTS, OPDS and WebDAV import/sync, and user-provided book-source workflows.

Featured in iOS Dev Weekly #751 — From WebView to CoreText: Building a Native EPUB Reader for iOS.

Why Yuedu

• Native iOS reader UI built with SwiftUI and CoreText, not a WebView-first reading surface.
• CoreText pagination for stable reading positions, highlights, and TTS progress.
• CJK vertical writing with right-to-left reading flow and vertical table of contents.
• Local-first library for EPUB, TXT, Markdown, and local manga archives.
• Online reading workflows through user-provided RSS, OPDS, WebDAV, web pages, and compatible source rules.
• Clear project boundary: Yuedu does not bundle, recommend, or distribute copyrighted content sources.

Features

Area	Capability	Status
Local books	EPUB reflowable reading with chapter navigation, images, links, bookmarks, highlights, annotations, and TTS	Available
EPUB3 features	MathML, SVG, embedded fonts, media overlays, fixed-layout, BIDI/RTL, canvas, CSS multi-column, PLS/SSML, CFI, bindings, epub:switch, indexes, multiple renditions	Available
Local books	TXT and Markdown reading	Available
Manga	Local .cbz / .zip manga archives and compatible source-based manga reading	Available
Audiobooks	Book-source audiobook streaming and player	Available
Reader modes	Paged and scroll reading modes	Available
CJK typography	Vertical writing, right-to-left flow, CJK punctuation handling, and vertical table of contents	Available
Library import	OPDS catalog import	Available
Sync/import	WebDAV import and sync	Available
Online reading	RSS / Atom feeds and native article reading	Available
Online reading	Web article normalization into clean long-form reading content	Available
Book sources	Legado-compatible source rules for user-provided online reading workflows	Available
Rendering quality	IDPF EPUB3 sample suite validated (up to Linear Algebra), MathML rendering, EPUB regression samples and compatibility checklist	Available
EPUB layout	Fixed-layout EPUB	Available
Accessibility	Broader VoiceOver, Dynamic Type, and touch target work	Planned

Supported Formats

Category	Supported	Notes
Local books	EPUB, TXT, Markdown	EPUB support focuses on reflowable books and native CoreText rendering.
Manga archives	CBZ, ZIP	Opened in a dedicated image reader.
Online feeds	RSS, Atom	Articles are extracted and read inside the native reader.
Catalogs and sync	OPDS, WebDAV	Import books from catalogs and WebDAV servers; sync through WebDAV.
Source rules	Legado-compatible rules	Format compatibility only; no third-party source rules are bundled.
Not the current focus	PDF, MOBI, AZW3, FB2, DOCX	Yuedu is intentionally iOS-native and CoreText-focused rather than a broad cross-platform format suite.

Screenshots

Library and Reader

Yuedu presents a local-first bookshelf, native reader controls, CJK vertical reading, annotations, TTS, manga, RSS, and import workflows.

Reading Experience

CJK vertical writing, highlights, annotations, and TTS are part of the native reading surface.

Workflows

Yuedu also covers manga reading, RSS reading, OPDS/WebDAV import, and compatible user-provided book-source workflows.

Downloads

• Download from the App Store
• Join the latest TestFlight beta
• Support
• Privacy Policy
• Telegram group

Yuedu Reader currently targets iOS 18.0+.

Roadmap

Now

• Polish audiobook streaming experience.

Next

• Better web article normalization.
• Richer manga sources and reader gestures.

Later

• TestFlight feedback loop.
• More accessibility work.
• More automated rendering regression tests.

See open issues labeled help wanted or good first issue if you want to contribute.

Getting Started

Requirements for development:

• iOS 18.0+
• Xcode 16+
• Swift 5 language mode in the Xcode project

git clone https://github.com/CHANG-JUI-LIN/Yuedu-reader.git
cd Yuedu-reader
open Yuedu-Reader.xcodeproj

Select the Yuedu-Reader scheme and build for a simulator or device. Or run:

./scripts/build.sh

Troubleshooting

• App Store vs TestFlight: App Store is the stable release. TestFlight receives newer builds first and may include unfinished behavior.
• EPUB rendering bugs: Please use the EPUB rendering bug template. Include screenshots from Yuedu, screenshots from Apple Books if possible, EPUB type/version, chapter/page location, expected behavior, and actual behavior.
• WebDAV, OPDS, RSS, or source-rule issues: Include the URL or server type, the visible error message, the action that failed, and confirmation that the content source is legal and user-provided.
• Copyrighted content: Do not upload copyrighted books publicly. A minimal synthetic EPUB or redacted sample is preferred.

Project Boundary

Yuedu Reader is a reader engine and app shell. It does not include, host, recommend, or distribute copyrighted content sources.

Users are responsible for making sure imported files, RSS feeds, websites, custom rules, cookies, accounts, and generated content comply with applicable laws, copyright requirements, and website terms.

The project will not accept contributions for built-in piracy sources, DRM circumvention, paywall bypassing, private-token sharing, cookie harvesting, or anti-bot bypass logic.

Legado compatibility is a source-rule format compatibility target only. Yuedu Reader does not bundle third-party source rules and is not affiliated with the Legado project.

Architecture Notes

Most EPUB readers use WebView. Yuedu uses CoreText for the main reader so it can control pagination, text ranges, highlights, TTS synchronization, and CJK vertical rendering more precisely.

Yuedu currently has two EPUB rendering paths that share the same CSS resolution and CoreText drawing layer:

• Legacy HTML attributed-string builder
• RenderableNode IR pipeline

Most contributors do not need to understand the full engine before working on UI, docs, localization, EPUB testing, WebDAV, RSS, or source-rule features.

For details, see:

• CoreText contributor notes
• Architecture notes
• EPUB compatibility checklist
• EPUB regression samples

Contributing

Yuedu welcomes focused contributions in documentation, screenshots, EPUB testing, localization, accessibility, WebDAV/OPDS testing, reader UI polish, and rendering compatibility.

Start here:

• Contributing guide
• EPUB rendering bug template
• CoreText contributor notes
• EPUB regression samples
• Demo media workflow

Repository Layout

Modules/
├── Core/                 # EPUB/TXT/MD parsers, CoreText engine, BookSource, RuleEngine, TTS, Comic
├── Features/             # SwiftUI screens: Bookshelf, Reader, RSS, BookSource, Search, Settings...
├── Services/             # LibraryStore, Online, WebDAV, iCloud, OPDS, Network, Account...
└── SharedUI/             # DesignSystem, Components, Extensions, Adaptive layout
Resources/                # Assets.xcassets, Assets/, en.lproj, zh-Hans.lproj, zh-Hant.lproj
Targets/Yuedu/            # SharedApp, iPhone/, iPad/ entry points

Development Notes

• Use localized() for user-facing strings; update all three .lproj files.
• Keep reading position based on content coordinates, not page indexes.
• Style UI with design-token APIs: DSColor, DSFont, DSSpacing.
• Add a compiling SwiftUI preview (#Preview or PreviewProvider) when creating or changing view code wherever practical.
• CSS properties added to ResolvedStyle must mirror in RenderStyle, update RenderStyle.from, and handle both rendering paths.
• Nested block CSS margins accumulate through inheritedBlockMarginLeft.
• Keep source/rule-engine work limited to legal, user-provided content workflows.

AI-Assisted Development

This repository is developed with heavy AI-assisted collaboration, including code generation, refactoring, documentation, and review support. Human review and project ownership remain part of the workflow.

If you strongly prefer strictly human-authored code or are uncomfortable with AI-assisted development, please review the project with that expectation in mind.

License

MIT. See LICENSE. This project links against Readium components, which are BSD-licensed.