Agenda Tech
A fully local, encrypted, zero-network Android calendar — the calendar piece of the Files
Tech suite, built without cloud.
🇫🇷 Version française
Bug reports are welcome in the
issues.
Installation
- Download the universal APK (
agenda-tech-universel-<version>.apk) from the
latest release.
- Open it on your Android phone (8.0 or later). Allow "install unknown apps" if prompted.
- That's it — no sign-up, no account, no connection.
The APK is universal (works on every device, no variant to pick) and signed.
Features
- Views: Month (smooth swipe between months; dots, titles in the grid or one row per day, pinch
to switch), Week, Day and Agenda (list).
- Events: create/edit, all-day, description, per-event colour.
- Place: label, postal address (street, postcode, city) and GPS coordinates — a tap on the pin,
in the editor or in a day's list, opens the place in your maps app: the coordinates when they are
valid, else the address, else the place name (with no location permission at all).
- Share an event as text or as an
.ics file (editor's ⋮ menu), to the app of your choice — the
app sends nothing itself.
- Undo a deletion: "Undo" in the bar brings back the event, its reminders, or the date taken out
of a series.
- Public holidays of ten countries (Austria, Belgium, France, Germany, Italy, Luxembourg, Spain,
Switzerland, the United Kingdom, the United States), national ones, worked out on the phone, off by
default — checked day by day from 1990 (1991 for Germany, 2008 for Spain) to 2060 against an
independent reference.
- Recurrence (RFC 5545): daily / weekly (chosen days) / monthly / yearly, with interval, ending
after N occurrences or on a date, and editing/deleting a single occurrence (the iCalendar
RECURRENCE-ID model).
- Reminders via exact alarms, re-armed after a reboot: preset delays or a free value, and your
choice of sound (a system ringtone or your own audio file).
- Birthdays: a first-class kind of event — all-day, yearly, endless, set in one tap — with the
age shown beside the name ("Paul · 42"), derived from the date of birth and never stored. Not
shown at all if you do not know the year.
- Duplicate an event: the copy keeps everything but the identity; change the date and save.
- Encrypted
.atbak backup: export/restore everything (calendars, events, recurrences,
places, reminders) in a password-protected file (PBKDF2 600,000 iterations + AES-256-GCM) — keep
it wherever you like, cloud included.
- Automatic backup (optional): the same encrypted
.atbak, written on its own once a week into
a folder you pick, keeping the four most recent. It is the one place where the app keeps a
password — wrapped by the AndroidKeyStore, erased when you turn the option off; the trade-off is
spelled out in SECURITY.md.
.ics import / export (RFC 5545) through the system file picker — an interchange format,
which does not replace the backup (it loses reminders, colours and the calendar structure).- Import from the device calendar (Google, Exchange, local calendars), read-only — the app
copies what is already synced onto the phone, with no network.
- Search across the whole calendar (title, description, place, address, city) — accent- and
case-insensitive: "reunion" finds "Réunion".
- Optional lock with a PIN and/or biometrics.
- Dark theme (GitHub-styled), home-screen widgets, in English, French, German, Italian and Spanish (corrections welcome: TRANSLATING.md).
Privacy
- No internet permission. Nothing leaves the device unless you share or export it yourself: no
cloud, no analytics, no ads, no third-party tracking SDK.
- Encrypted at rest. A Room database backed by SQLCipher (AES-256); the master key is
wrapped by the Android KeyStore (hardware/TEE on supported devices).
- End-to-end encrypted backups. The
.atbak file is encrypted by your password alone: it stays
unreadable even sitting on a cloud. Format documented in SECURITY.md.
- Privacy on screen.
FLAG_SECURE (no preview in Recents, screenshots blocked), cloud backups
excluded (allowBackup=false).
Details: SECURITY.md · PRIVACY.md.
Tech stack
Kotlin · Jetpack Compose (Material 3) · Hilt · Room + SQLCipher · Coroutines/Flow · typed
Outcome/AppError · Timber · JUnit5 + Truth + MockK tests.
applicationId: com.filestech.agenda_tech — minSdk 26 (native java.time) / compileSdk 37.
Architecture (layers)
core/ Outcome, AppError, crypto (AeadCipher, KeystoreManager, PinHasher), text, logging
domain/ pure models (Calendar, Event, RecurrenceRule, Reminder, DeviceCalendar/DeviceEvent
+ enums), repository interfaces, use cases, recurrence engine (DST-correct),
device/ pure mapper from a calendar row to an Event ← no Android dependency
data/ Room entities, DAOs, AppDatabase (SQLCipher), mappers, repository impls — including
Calendar Provider access (device import), hidden behind a domain interface
di/ Hilt modules
ui/ theme, navigation, screens (Month/Week/Day/Agenda, editor, settings, lock…)
system/ exact alarms for reminders · notifications
widget/ Glance widgets (agenda + date icon)
The domain is 100% pure; the only domain↔Room crossing point is
data/repository/EntityMappers.kt. Recurrence is stored in structured columns (rrule_*) on the
event — the iCalendar model (RRULE is a property of the VEVENT).
Building from source
git clone https://github.com/gitubpatrice/AGENDA-TECH.git
cd AGENDA-TECH
./gradlew :app:assembleDebug # debug APK (splits + universal)
./gradlew :app:testDebugUnitTest # unit tests
Release signing expects a keystore.properties file (not versioned); the debug build does not need
one.
Versions
version.properties, at the root, is the single source of versionCode / versionName:
versionCode=NN # see the file for the current values
versionName=X.Y.Z
The versionCode must always increase: Android refuses to install an APK whose versionCode is
lower than the installed one, and the user only sees an unexplained failure. It is bumped by
hand, before building a release APK — never after.
The build fails if the file is missing or unreadable: producing nothing beats producing an APK
carrying a silently wrong version.
Security & privacy
- Threat model, encryption, lock: SECURITY.md.
- Privacy policy (permissions, data, contact): PRIVACY.md.
- Terms of use: TERMS.md. For both documents, the French version prevails.
- Reporting a vulnerability: see SECURITY.md.
Licence
Apache License 2.0 — © 2026 Patrice Haltaya / Files Tech. Third-party libraries and their
licences: THIRD_PARTY_NOTICES.md.
