Atlas — fully-offline maps for Android

Atlas is an open-source Android maps app that renders, searches, routes, and navigates entirely offline. You supply a PMTiles archive (OpenMapTiles schema, e.g. produced with Planetiler); Atlas does the rest with zero network access.

The zero-network rule is structural, not a setting: the merged APK does not hold the INTERNET permission at all — no ACCESS_NETWORK_STATE, no ACCESS_WIFI_STATE either — and a build-time check fails the build (and CI) if any dependency ever smuggles one back in through its manifest.

Features

• Offline map rendering — MapLibre Native with an OSM Liberty-derived style in light and dark themes, dynamic Material You accent, bundled sprites and glyphs. No tile server, ever.
• Offline search — places and POIs indexed into an on-device full-text index (Room FTS) at archive import and as routing data is prepared.
• Offline routing — BeeRouter (a BRouter descendant) drives turn-by-turn car, bike, and walking routes. Plan between searched, saved, or map-selected places, with up to nine stops. Edit either endpoint, swap the route, and drag stops into order. Chosen endpoints work without GPS; use Your location to start navigation. The routing graph is built on demand per 5° region from the same PMTiles archive, in a separate process so a heavy build can't disturb navigation.
• Turn-by-turn navigation — GPS (no Play Services), voice guidance via the system TTS engine (works great with Maise), spoken cues and turn banners, automatic rerouting when you leave the route.
• Own your data — one archive file covers a country (or the planet); everything else Atlas stores is derived from it on your device.

How it works

1. Import — pick a .pmtiles file; Atlas copies it to internal storage, fingerprints it, and builds the low-zoom place index for search.
2. Render — the style template is resolved against the active theme's palette and pointed at the local archive; tiles come straight off disk.
3. Route — on a route request, Atlas cuts the OMT vector tiles covering the origin/destination into BeeRouter's segment format (.rd5), then runs the stock routing engine over them. Segments are cached per 5° bucket; Settings offers a "prepare everything" pass for power users.
4. Navigate — fixes from the platform LocationManager are snapped to the route; progress, spoken maneuvers, and off-route reroutes update live.

Data caveats (honest limits)

Routing from OpenMapTiles-derived vector data is coarser than routing from raw OSM PBF: the schema carries no turn restrictions, no maxspeed/surface/access tags, and no elevation, so profiles fall back to class-based defaults and ascend/descend read zero. Turn restrictions are therefore not honored. A routing-enriched Planetiler profile is the natural future upgrade.

Building

./gradlew assembleDebug        # debug APK
./gradlew :app:assembleRelease # signed release APK (needs key.properties)

Release signing follows the usual key.properties scheme: a gitignored file at the repo root with storeFile, storePassword, releaseAlias, and releasePassword pointing at your upload keystore. Without it, release builds come out unsigned. CI (.github/workflows/build.yml) builds a signed AAB plus a universal APK on every push to main from the org's secrets.

versionCode is derived from git rev-list --count HEAD, so every commit ships a higher version than the last.

Test corpus

The heavy Melbourne differential-test fixtures (app/src/test/fixtures/melbourne.{pbf,pmtiles}) are gitignored — too large for git. Tests that need them skip gracefully when they're absent, so a fresh clone builds and tests green. To run the full differential suite, generate the pair from an OSM extract with Planetiler (bbox extract) and osmium.

License

Atlas is MIT licensed.

Third-party components retain their own licenses, documented in place:

• BeeRouter is vendored at app/src/main/kotlin/com/danemadsen/atlas/beerouter/ (MPL-2.0, with its BRouter heritage) — local modifications are listed in its VENDORING.md.
• MapLibre Native, the OpenMapTiles schema, the PMTiles format, the OSM Liberty style, and the bundled fonts/sprites are used under their respective licenses; the in-app attribution screen carries the full list.
• Map data ultimately derives from OpenStreetMap (ODbL, © OpenStreetMap contributors).