Falco — Hetzner Manager for Android

Privacy-respecting Android client for Hetzner Online. Manage Hetzner Cloud, Robot (dedicated servers + Storage Boxes), DNS Console and Object Storage from one secure app.

Falco is community software and is not affiliated with Hetzner Online GmbH. Hetzner is a trademark of Hetzner Online GmbH.

Highlights

• 100 % free software (GPL-3.0-or-later) — no Google Play Services, no Firebase, no proprietary dependencies. Designed to be reproducibly buildable on F-Droid.
• Multi-account, multi-project — switch between Hetzner customers and Cloud projects on the fly. Per-account credentials.
• Hardened storage — credentials in EncryptedSharedPreferences with the master key bound to the Android Keystore (StrongBox-backed when available).
• Biometric gate — BiometricPrompt (Class 3 / Device Credential) on app start; auto-relock on background timeout.
• TLS 1.3 only with certificate pinning for every Hetzner endpoint (Cloud, Robot, DNS, Object Storage). Pins are root anchors so they survive Let's Encrypt's leaf rotation cycle.
• FLAG_SECURE on every screen, allowBackup="false", auto-backup excluded.
• Localised in 7 languages (en, de, es, fr, it, ru, zh-CN).

Features

Hetzner Cloud

• Servers: list, detail, metrics, create wizard, power actions, reset password, rebuild, change type, ISO attach/detach, rescue mode, backup toggle, console request, reverse DNS, rename, protection, delete.
• Volumes: list, create wizard with live price estimate, attach/detach, rename, resize, format, automount, protection, delete.
• Networks: list, create wizard, subnets add/delete, routes, change IP range, expose to vSwitch, protection, delete.
• Floating IPs: list, create wizard, assign/unassign, change reverse DNS, protection, delete.
• Firewalls: list, create, edit rules, apply to / remove from resources.
• SSH keys: list, create, rename, delete.
• Primary IPs: list, create, assign/unassign, protection, delete.
• Load Balancers: list overview (create + actions wired in repo, UI growing).
• Certificates: upload PEM or request managed (Let's Encrypt) certs, list, delete, retry managed issuance.
• Placement Groups: list, create, delete.
• Storage Boxes: full detail screen — list, snapshots, subaccounts, password reset, access toggles (SSH/Samba/WebDAV/ZFS).

Hetzner Robot

• Servers: rich list (status dot, chips, IPv4/IPv6 with copy, datacenter, paid-until), detail screen, reset (sw/hw/manual), Wake-on-LAN, rescue mode enable/disable, reverse DNS setter, server cancellation + withdraw.
• Failover IPs: list, route to active server, unroute.
• vSwitches: list, create, update, delete, attach/detach servers.
• SSH keys: list, create, delete.

DNS Console

• Zones: list, create, update, delete, single-zone fetch.
• Records: list, create, update, delete, single-record fetch, bulk create/update, BIND import/export, validate.
• Primary servers (secondary zone sources): full CRUD.

Object Storage (S3-compatible)

• Buckets: list, exists, create, delete.
• Objects: list (prefix browser), upload via foreground service, download via signed URL, head/stat, copy, delete (single + batch), presigned upload URL.
• Bucket settings: versioning toggle.

Building

Requires:

• JDK 17 (set via Gradle toolchain — auto-provisions if absent).
• Android SDK 35 (compileSdk).
• Kotlin 2.1, AGP 8.x, Compose BoM 2025.01.

git clone https://github.com/Kiefer-Networks/Falco.git
cd Falco
./gradlew :app:assembleDebug

The debug APK lands in app/build/outputs/apk/debug/.

Release builds

Release builds are signed with a real keystore. Provide one via keystore.properties at the repo root (this file is git-ignored):

storeFile=keystore.jks
storePassword=YOUR_STORE_PASSWORD
keyAlias=upload
keyPassword=YOUR_KEY_PASSWORD

Then:

./gradlew :app:assembleRelease   # APK
./gradlew :app:bundleRelease     # AAB

Quality gates

./gradlew :app:lintDebug          # Android Lint
./gradlew testDebugUnitTest       # unit tests

CI runs both on every push.

Architecture

• UI: Jetpack Compose + Material 3, single-Activity (Hilt entry point).
• DI: Hilt.
• Networking: Retrofit 2 + OkHttp 4, Kotlin Serialization JSON converter. TLS pinning via CertificatePinner (SPKI SHA-256 of trust anchors).
• Storage: Jetpack DataStore for non-sensitive prefs; EncryptedSharedPreferences (AES-256-GCM, Keystore master key) for Hetzner tokens / S3 secrets / Robot credentials.
• S3: MinIO Java SDK 8.5 routed through the same hardened OkHttp client so it inherits TLS + pinning policy.
• Concurrency: Kotlin Coroutines + StateFlow / SharedFlow.

Permissions

Permission	Why
INTERNET	API calls (Hetzner + S3).
ACCESS_NETWORK_STATE	Network availability checks.
USE_BIOMETRIC	Unlock gate.
POST_NOTIFICATIONS	Upload-progress notifications (Android 13+).
FOREGROUND_SERVICE + FOREGROUND_SERVICE_DATA_SYNC	S3 upload service.

No location, contacts, broad storage, accounts, or analytics permissions.

Localisation

The default language is English. Falco ships with full translations of the ~530 user-facing strings for: German, Spanish, French, Italian, Russian and Simplified Chinese. Help us add more in app/src/main/res/values-*.

Donate

If Falco saves you time, please consider supporting development via Liberapay — de.liberapay.com/beli3ver. Liberapay is non-profit, anonymous-friendly and takes no platform cut.

Contributing

PRs welcome. Please:

1. Match the project's code style (Compose-first, no Views, no XML layouts).
2. Add strings to all seven values-*/strings.xml files when introducing user-visible text.
3. Run ./gradlew :app:lintDebug and ./gradlew testDebugUnitTest before opening a PR.

License

GPL-3.0-or-later. See LICENSE for the full text.