Sheafs
A small, native EPUB reader for iPhone and iPad (iOS 27.0 and later), built for the foldable iPhone Duo.
SwiftUI, TextKit and Foundation only. No web views, no third-party dependencies.
Website: https://kad-air.github.io/sheafs/ (the docs/ folder, published by GitHub Pages).
- Reads EPUB 2 and 3 with the system's own typography: New York, Georgia, Palatino, Charter and
friends, paper / sepia / night / black themes, adjustable size, leading and margins, justified or
ragged, hyphenation. Chapters are paginated like a book, not scrolled. The book's own stylesheets
are honoured, tables are laid out as tables, and a double-tap opens a picture full screen.
- Highlights, notes and bookmarks, shareable as Markdown. Search inside a book, and share a
quote from the selection menu.
- Made for iPhone Duo. On the cover display it is a one-page reader with the system's vertical
toolbar. Open the device in landscape and it becomes a two-page spread with the gutter on the
fold. Fold it halfway like a book and the pages keep clear of the crease; stand it up like a
laptop and the page moves to the upper half with reading controls below the fold. Fold and
unfold mid-chapter and you stay on the same words.
- OPDS catalogs. Add any OPDS 1.2 catalog (self-hosted libraries, Calibre, Project Gutenberg),
browse, search and download straight into the library.
- Reading position sync using the KOReader sync protocol ("kosync"), so a position set on one
reader shows up on the others. The document key is the KOReader partial MD5 of the file bytes;
positions are written as CREngine xpointers, the dialect KOReader and CrossPoint use.
- Volume buttons turn pages if you want them to (Settings → Appearance → Reading): up for
the next page, down for the previous one.
- Open in Sheafs from Files, AirDrop and the share sheet, or drop EPUBs into the app's
Documents folder.
Building
Requirements: Xcode 27.1, XcodeGen (brew install xcodegen).
scripts/bootstrap # creates Config/Signing.xcconfig and generates Sheafs.xcodeproj
open Sheafs.xcodeproj # or build from the command line:
xcodebuild -project Sheafs.xcodeproj -scheme Sheafs -destination 'platform=iOS Simulator,name=iPhone Duo' build
For a device build, put your Apple Developer team id in Config/Signing.xcconfig
(DEVELOPMENT_TEAM = XXXXXXXXXX). The file is git-ignored.
scripts/check is the one command that must pass before a change is done. It checks the tree for
leaked personal data, regenerates the Python reference data the tests are anchored on, runs the
SheafsKit tests on the Mac, builds the app for the iPhone Duo simulator and runs the app's own
tests there.
scripts/hinge/hinge 110 folds the booted iPhone Duo simulator to 110° (book pose); 0 closes it,
180 lays it flat, and hinge orient landscape-left turns it (device landscape shows the inner
display in portrait; partly folded, that is tabletop). See THIRD_PARTY_NOTICES.md.
scripts/screenshots takes the App Store screenshots in every pose on its own simulator, with
public-domain books from Standard Ebooks, and checks each against
App Store Connect's iPhone Duo sizes. scripts/marketing turns them into App Store tiles (a headline
and the screenshot in a device frame) in each style under marketing/styles, from the copy in
marketing/tiles.json.
Layout
Sheafs/ — the app: App (entry, tabs), Library (SwiftData models, import, grid), Reader
(typesetting, pagination, the pager, Duo layout, chrome), Catalog (OPDS browser), Settings,
Sync (kosync service), Support.Packages/SheafsKit/ — a Foundation-only package with the EPUB container (Zip, EPUB), the
XHTML-to-block converter and xpointer model (Text), the OPDS client (OPDS) and the KOReader
sync client (KOSync). swift test runs on the Mac.scripts/ — check, bootstrap, the Python reference generators, and the simulator hinge tool.docs/ — the landing page GitHub Pages serves (scripts/site-shots frames its screenshots,
scripts/check-site checks it).
Sync setup
In Settings → Sync & Accounts → Reading Position Sync, enter the server URL (for a self-hosted server this may
include a path, e.g. https://example.com/kosync/), a user name and a password, then tap
Register Account once and Test Connection. Any reader that speaks the KOReader sync protocol
can share the account; the same EPUB file (byte for byte) must be on each device.
Acknowledgements
Volume-button page turns follow the approach of Readest
(AGPL-3.0), which showed it working well on iOS: iOS offers no volume-button event to a reader, so
the app watches the system volume and puts it straight back after every press. Sheafs'
implementation is its own, and no Readest code is included.
License
MIT. See LICENSE and THIRD_PARTY_NOTICES.md.
