DeckCraft for Android (arm64-v8a)

An unofficial Android port of DeckCraft — the real engine and egui interface, packaged as a NativeActivity APK for sideloading on arm64 devices.

Upstream project	storytold/deckcraft — Apache-2.0 OR MIT
Pinned commit	be14248 (upstream version 0.5.0)
Android package	ai.storyteller.deckcraft
Published APK	deckcraft-0.5.0-arm64-v8a-20261013b.apk — 29.1 MB, arm64-v8a, signed (release v0.1.2, 2026-10-13)
APK sha256	c1d211868ab74de4f93b009a026b86f477f61f37c14a745c5752ee0e81a1b009
Upstream files changed	3 files (1 of them new) — see patches/
New port crate	apps/deckcraft-android/ — 1574 lines of Rust plus resources

What this repository is

This is not a fork of DeckCraft. It holds only the Android layer, so it stays small, readable, and obviously separable from upstream:

apps/deckcraft-android/     the new shell crate — copy it into your checkout of upstream
patches/                the diff against upstream — apply it after checking out the pin
docs/PORT-NOTES.md      what was changed and why, fix by fix, with how each one was checked
scripts/                cross-compile environment, build and verify scripts (from shared-android-port)
CHANGELOG.md            what is in the published APK

The Android layer is not a reimplementation. It is a shell crate that fills the same Services struct the desktop and web shells fill, so the real engine and the real egui UI run unchanged.

Build it

Prerequisites: Rust (rustup) with the aarch64-linux-android target, Android SDK + NDK r27, a JDK 21, and cargo install cargo-apk.

git clone https://github.com/storytold/deckcraft.git
cd deckcraft
git fetch --depth 1 origin be14248577b92059eb2b8c0c9460cceffbc1f01d
git checkout FETCH_HEAD                        # the exact commit this port targets
git apply -3 /path/to/0001-deckcraft-android-port.patch
cp -r /path/to/deckcraft-android apps/             # the shell crate from this repository

# any keystore of your own signs an installable APK; a throwaway test key is fine for sideloading
keytool -genkeypair -keystore ks.jks -alias deckcraft -keyalg RSA -keysize 2048 -validity 10000 \
        -storepass android -keypass android -dname "CN=Local Test, O=Local, C=US"
export CARGO_APK_RELEASE_KEYSTORE="$PWD/ks.jks" CARGO_APK_RELEASE_KEYSTORE_PASSWORD=android
cargo apk build --release -p deckcraft-android

scripts/android-env.sh is the cross-compile environment this port was built with (the NDK linker and the C compiler the native dependencies need), scripts/build-apk.sh wraps the build, and scripts/verify-apk.sh checks the artifact: aapt2 dump badging, apksigner verify, and llvm-nm on the .so inside the APK.

Install

adb install -r deckcraft-0.5.0-arm64-v8a-v3.apk

or copy the APK to the device and open it (installing from unknown sources must be allowed).

On first run, grant Settings ▸ Apps ▸ DeckCraft ▸ Special access ▸ All files access if you want the in-app picker to reach files outside the app's own folders. Without it, Android 10+ refuses a read_dir of shared storage by path, and the picker can only offer the app's own directory.

Verification status

Everything below was checked on the machine this port was published from, in October 2026. A tick means the check was run, not inferred; the wording says how far it goes.

Claim	How it was checked	Result
patches/…patch applies to a clean checkout of the pin	fresh git init + git fetch --depth 1 origin be14248577b92059eb2b8c0c9460cceffbc1f01d + git apply --check	✅ applies cleanly
The assembled tree equals the tree the APK was built from	file-by-file SHA-256 (line endings normalised) over every patched file and every file of the port crate	✅ 12 files identical, none differing
The port crate compiles for Android	cargo check -p deckcraft-android --target aarch64-linux-android, run in a tree assembled from scratch (fresh git fetch of the pin, patch applied, port crate copied in)	✅ exit 0, from the freshly assembled tree (clone + patch + crate), not the build tree
The port crate's own tests	cargo test -p deckcraft-android in the freshly assembled tree	✅ 3/3 pass
APK is signed and is the right artifact	apksigner verify --verbose, aapt2 dump badging, sha256	✅ v2/v3 signatures true, native-code: 'arm64-v8a', package ai.storyteller.deckcraft
Behaviour on real hardware	hand-testing on the porter's arm64 tablet	⚠️ the fixes below were found and driven by that testing; each published binary is not individually re-verified here

Before trusting the APK: the source side is verified as listed above; runtime behaviour only as far as docs/PORT-NOTES.md says per fix, plus the tablet testing that produced those fixes. There is no automated device test in this repository.

Known gaps

• Runtime verification is hand-testing only, plus the source-side checks in the README.
• No audio output (cpal has no Android backend here) — embedded audio in a presentation is silent.
• All files access is a manual grant; without it the picker offers only the app's own directory.
• Split-screen is defended, not proven — config_changes is what keeps the Activity from being recreated; an aggressive device that recreates it anyway will still show the blank-surface symptom.
• Android 16 ignores the status-bar opt-out used by theme variant A; the port ships variant B.

The rest of this set

• photocraft-android — PhotoCraft 0.7.0
• vectorcraft-android — VectorCraft 0.9.0
• wordcraft-android — WordCraft 0.5.0
• pdfcraft-android — PdfCraft 0.6.0
• gridcraft-android — GridCraft 0.5.0
• shared-android-port — build/verify scripts + the cross-compile environment

Credits and licence

DeckCraft is © its authors at storytold/deckcraft and is dual-licensed Apache-2.0 / MIT; both licence texts are kept here. The Android layer in this repository is an unofficial modification by @kanaaka, carrying the same licence. Not affiliated with or endorsed by the upstream project. See ATTRIBUTION.md.