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What's new in bitchat for Android (github version) 2.0.3

Bitchat Android 2.0.3

Signed phone and Wear OS builds from v2.0.3 (source commit dfc67dad41691128bc6e7425bd69f2f409cb5bbf). Canonical unsigned outputs were built independently twice and matched byte-for-byte before local signing.

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Highlights

Smoother busy chats: reduce UI stalls during bursts of geohash presence and mesh activity, batch identity updates, and compose participant lists lazily.
Bounded resource use: cap packet-processing queues and pace sync responses to keep heavy traffic from creating an unlimited backlog.
More reliable connectivity: continue retrying Nostr relays after network and DNS failures, with refreshed relay data.
Messaging correctness and security: verify incoming geohash event signatures before duplicate detection; preserve original compressed packet bytes for cross-client signature verification and forwarding; improve duplicate detection and geohash channel routing.
Safer panic wipe: remove the private-conversation database files if normal conversation erasure fails.
Wear OS polish since 0.1.1: shape-aware layouts for small round displays and larger fonts, compact fading chat headers, steadier scroll controls and autoscroll, refreshed icons, and an ongoing activity for returning to the mesh session.

History retention

Public chat and channel timelines now retain the latest 1,000 messages each, with up to 20 recently active channel timelines in memory. Older public messages are not archived by this change. Private-conversation history keeps its existing persistent retention policy.

Versions

Phone: 2.0.3 (40), minimum API 26, target API 37.
Wear OS: 0.1.5 (1000000006), minimum API 33, target API 37.
Both use application ID com.bitchat.droid.

The Wear layout, icon, and ongoing-activity changes above are new relative to the previous GitHub release, but were already included in the separate Play Wear 0.1.4 release. Wear 0.1.5 additionally incorporates the shared mesh, sync, and identity fixes.

Verification and known limitations

Independent local and tagged CI builds matched. Exact-tag provenance, signatures, signing continuity against prior artifacts, bundle validation, payload comparisons, and release checksums passed. Unit and contract checks passed (860 tests passed, 3 skipped). A clean installation and an in-place upgrade from the signed 2.0.1 APK launched to onboarding on a disposable emulator.

Known issue: QR scanner initialization can crash in this release; the pending crash fixes are not included. Full physical-device/cross-client/endurance and Play-delivered install/upgrade testing have not been completed. Existing lint errors and unavailable changed-line coverage remain; these are not claimed as passes.

Downloads and signing

Only four signed APKs, the two signed Play-upload AABs, and three reproducibility metadata files are attached. No unsigned APK or AAB is published; BITCHAT_SHA256SUMS.unsigned contains their canonical hashes, not binaries.

bitchat-android-arm64.apk — modern Android phones.
bitchat-android-universal.apk — compatibility fallback.
bitchat-android-x86_64.apk — x86_64 devices and emulators.
bitchat-android-wear.apk — direct Wear OS installation.
bitchat-android-play-upload.aab — signed phone bundle for Google Play.
bitchat-android-wear-play-upload.aab — signed bundle for the dedicated Wear OS track.

Certificate SHA-256 fingerprints:

GitHub APK and existing Play upload certificate: 3b03fa66a5451321100792f5b55a7b4966d5c8dc10c6daa40aa95ea489531bca.
Google Play app-signing certificate: 5e651dd0c80d1f57f2617964955085e28949dd04addac7b53fe9d2f11e172aa2.

Google signs Play-delivered APKs with its separate app-signing key; those APKs are not expected to be byte-identical to GitHub APKs.

Reproducible-build verification

Use Git, Docker with sufficient memory, and the GitHub CLI:

git clone github.com/permissionlesstech/bitchat-android.git cd bitchat-android git checkout v2.0.3 tools/reproducible-builds/build-in-container.sh .reproducible-build/verify-v2.0.3 gh release download v2.0.3 --pattern 'BITCHAT_BUILDINFO.json' --pattern 'BITCHAT_SHA256SUMS*' --dir .reproducible-build/metadata-v2.0.3 gh attestation verify .reproducible-build/metadata-v2.0.3/BITCHAT_BUILDINFO.json --repo permissionlesstech/bitchat-android gh attestation verify .reproducible-build/metadata-v2.0.3/BITCHAT_SHA256SUMS.unsigned --repo permissionlesstech/bitchat-android cmp .reproducible-build/verify-v2.0.3/SHA256SUMS.unsigned .reproducible-build/metadata-v2.0.3/BITCHAT_SHA256SUMS.unsigned

To verify all downloaded release files without rebuilding:

gh release download v2.0.3 --repo permissionlesstech/bitchat-android --dir .reproducible-build/download-v2.0.3 (cd .reproducible-build/download-v2.0.3 && shasum -a 256 -c BITCHAT_SHA256SUMS)

Full changelog: v2.0.1...v2.0.3

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Verified safe to install (read more)

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About bitchat for Android (github version) 2.0.3

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bitchat for Android

A decentralized peer-to-peer messaging app with dual transport architecture: local Bluetooth mesh networks for offline communication and internet-based Nostr protocol for global reach. No accounts, no phone numbers, no central servers.

This is the Android implementation of bitchat, fully protocol-compatible with the iOS version for cross-platform mesh communication.

bitchat.free

GitHub Releases

See it in action

Offline mesh conversation	Geohash globe picker

License

This project is released into the public domain. See the LICENSE file for details.

Features

Dual Transport Architecture: Bluetooth LE mesh for offline messaging, Nostr relays for internet-based messaging
Location-Based Channels: Geographic chat rooms using geohash coordinates over Nostr relays
Intelligent Message Routing: Automatically chooses the best transport, with queuing and retry when a peer is unreachable
End-to-End Encryption: Noise Protocol (XX pattern, X25519 + ChaCha20-Poly1305) for private messages over the mesh
Decentralized Mesh Network: Automatic peer discovery and multi-hop relay over Bluetooth LE (max 7 hops)
Wi-Fi Aware Transport: Higher-bandwidth local mesh on supported devices
Channel Chats: Topic-based group messaging with optional password protection (Argon2id + AES-256-GCM)
IRC-Style Commands: Familiar /join, /msg, /who style interface
Tor Support: Built-in Tor (Arti) for private internet connectivity
Emergency Wipe: Triple-tap to instantly clear all data
Cross-Platform: Binary protocol compatible with bitchat on iOS and macOS

Technical Architecture

Bluetooth Mesh Network (Offline)

Direct peer-to-peer within Bluetooth range, multi-hop relay through nearby devices
Noise Protocol sessions with forward secrecy; peer identities derived from static keys
Compact binary packet format with fragmentation, TTL routing, and deduplication
Adaptive duty cycling and connection limits for battery efficiency
Foreground service keeps the mesh alive within Android background execution limits

Nostr Protocol (Internet)

Global reach via public relays, geohash-based location channels
Private messages fall back to Nostr for mutual favorites when the mesh is unavailable
Ephemeral keys per geohash area

Android Stack

Kotlin, Jetpack Compose (Material 3), MVVM
Coroutines and Flow for all networking and state
Core components: MeshForegroundService (persistent connectivity), BluetoothMeshService / WifiAwareMeshService (transports), UnifiedMeshService (transport selection), NoiseSessionManager (encryption sessions), MessageRouter (mesh/Nostr routing with outbox retry)

Building

Requires Android Studio and the Android SDK (API 26+).

github.com/permissionlesstech/bitchat-android.git cd bitchat-android ./gradlew assembleDebug">

git clone github.com/permissionlesstech/bitchat-android.git cd bitchat-android ./gradlew assembleDebug

Install on a connected device:

adb install -r app/build/outputs/apk/debug/app-debug.apk

The app requests Bluetooth, location (required for BLE scanning), and notification permissions at runtime.

Release APKs and the Android App Bundle can be rebuilt byte-for-byte in the pinned Linux container. Maintainers should follow the Android release guide. See Reproducible builds for the build trust model and public GitHub/Google Play verification procedures.

Testing

# Unit tests ./gradlew test  # Lint ./gradlew lint  # Instrumented tests (requires a device or emulator) ./gradlew connectedAndroidTest

Note that BLE mesh behavior is difficult to emulate; protocol and session logic is covered by unit tests, while radio-level behavior needs real devices.

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