# F-Droid distribution

F-Droid builds use the application ID `social.flotilla.fdroid`. Preparation removes
Firebase, Google Services, Plausible, and the ACINQ native secp256k1 library.
Welshman's optional `nostr-wasm` accelerator uses its pure JavaScript verifier.
The normal Play/Zapstore build is unchanged.

Background notifications use `AndroidPushFallbackWorker`: WorkManager polls the
configured relays about every 15 minutes and posts local notifications. Android
Doze and background scheduling can delay delivery further.

Pomade login, registration, and key recovery use the JavaScript Argon2 adapter.
With Pomade's parameters (t=3, m=64 MiB, p=2, 32-byte output), a benchmark on a
2-core x86 machine measured 426 ms with `hash-wasm` versus 4.0 s with the adapter,
with matching digests. Physical-device timing has not yet been measured.

## Build

Preparation changes source and dependencies, so run it in a disposable checkout
with the Node, pnpm, Java, Android SDK, and Gradle versions pinned by this repository.

```sh
corepack enable
./scripts/fdroid/prepare.sh
./scripts/fdroid/build.sh
cd android
./gradlew assembleFdroidRelease
```

After preparation and the asset build, run the BouncyCastle key-operation and
BIP-340 vector tests from `android/` with:

```sh
./gradlew :app:testFdroidDebugUnitTest --tests social.flotilla.notifications.FallbackSecp256k1Test
```

`fdroid/app.gradle` registers `fdroid/tests` only in the prepared checkout.

The unsigned APK is written to
`android/app/build/outputs/apk/fdroid/release/app-fdroid-release-unsigned.apk`.
F-Droid should run preparation before its source scan, run the asset build afterward,
and use its configured Gradle runner for `assembleFdroidRelease`.

[`metadata/social.flotilla.fdroid.yml`](metadata/social.flotilla.fdroid.yml) is the recipe to submit
to `fdroiddata`. The listing's text, icon, feature graphic and per-version changelogs come from
`fastlane/metadata/android/en-US/` at the tag F-Droid builds. Preparation installs dependencies
before F-Droid's source scan, so the recipe scan-ignores `node_modules`, which holds FLOSS build
tools such as esbuild and sharp. The recipe installs JDK 21, which Capacitor needs, and Node from
nodejs.org at a pinned checksum, as a `.tar.gz` since the build server has no `xz`.

## Reproducible builds

F-Droid rebuilds each tag, downloads the apk at the recipe's `Binaries` url, and ships that apk
instead of its own when copying its signature onto F-Droid's build verifies. So the F-Droid app
carries the distribution key, the one `AllowedAPKSigningKeys` names, and can never switch to
F-Droid's key.

The release workflow's `fdroid` step runs `scripts/fdroid/reproduce.sh` in F-Droid's
`buildserver-trixie` image, the way fdroiddata's own CI builds a recipe, against the recipe in
`metadata/` pointed at the tag. It uploads the unsigned apk to the `flotilla-fdroid` generic
package on gitea, and `pnpm release:local fdroid-sign` signs it and uploads the result beside it.
The recipe in `metadata/` is the one both builds read, so a change to it goes to `fdroiddata` too.

## Updates

Stable releases use bare version tags such as `1.9.1`, and the recipe checks tags matching
`^[0-9]+\.[0-9]+\.[0-9]+$` against `versionCode` and `versionName` in
`android/app/build.gradle` at that tag.

The initial `fdroiddata` submission must still review scanner exceptions for FLOSS
build tools and optional OpenRouter use for a possible `NonFreeNet` declaration.