chatbit

---

chatbit is a fork of bitchat-android, the decentralized messenger started by Jack Dorsey. It stays compatible with bitchat on iOS and Android (Bluetooth mesh and geohash channels), and adds a security layer that is switched on from the first launch, with nothing to configure.

Download

Get the signed APK from chatbit.zap-info.com. The page lists the SHA-256 checksums and the VirusTotal report of each release.

Requires Android 8.0 or newer. The APK published on the website shows no ads.

Videos

Tutorials, real-life uses and explanations of how bitchat works, on the chatbit YouTube channel (in French, new videos every Tuesday and Friday):

Screenshots

What chatbit adds to bitchat

Privacy by default

• Tor (Arti) on from the first launch, with automatic route rotation and a one-tap "new route" button
• Messages are cut off if Tor drops, instead of leaking over the clear network
• Links open only in Tor Browser
• Screenshots blocked, notifications hidden, clipboard cleared after 60 seconds, photo metadata (EXIF) removed
• Incognito keyboard, ephemeral messages (24 h), no presence broadcast

Protection of your phone

• chatbit PIN lock on its own keypad (never the system keyboard)
• Duress PIN: entering it silently wipes everything
• Encrypted preferences and encrypted media vault, whose key is destroyed on wipe
• Automatic wipe after a chosen number of days without use

Clean public channels

• Base anti-flood always on: same text repeated, throwaway keys, generated nicknames (bot_xxxx), link spam, Zalgo text
• Full anti-spam mode with adjustable thresholds and rules, and a list of hidden senders
• Import and export of block lists (txt / json)

More ways to talk

• Private rooms encrypted end to end, carried over Nostr and Tor, joined with an invitation link or QR code
• Interactive globe of geohash channels, with an offline zone directory
• Offline sharing: a Wi-Fi hotspot serves the app to people nearby, with no Internet needed
• 34 languages, 8 accent colours, light and dark themes, a guided tour with the chatbit kitten

Inherited from bitchat

• Bluetooth LE mesh: multi-hop relay between nearby phones (up to 7 hops), works with no antenna and no server
• Nostr: geohash location channels and private messages over public relays when the Internet is available
• End-to-end encryption: Noise Protocol (XX, X25519 + ChaCha20-Poly1305) for private messages
• Proof of work (NIP-13) on outgoing messages to make spam costly
• Emergency wipe: triple-tap to clear all data
• IRC-style commands (/join, /msg, /who…), plus chatbit short forms (/j, /m, /w…)

Building from source

Requires the Android SDK (API 26+) and JDK 21.

git clone https://github.com/ledokter/chatbit.git
cd chatbit
./gradlew assembleDebug
adb install -r app/build/outputs/apk/debug/app-debug.apk

A build made from this repository alone is unbranded: it is called "Chat (unbranded)" and uses a plain chat bubble icon. The chatbit name, the kitten mascot and the chatbit icons are not part of this repository (see TRADEMARKS.md).

Tests:

./gradlew test                  # unit tests
./gradlew lint
./gradlew connectedAndroidTest  # needs a device or emulator

Bluetooth mesh behaviour is hard to emulate: protocol and session logic are covered by unit tests, radio behaviour needs real phones.

Privacy

chatbit has no account and no phone number. See docs/chatbit/PRIVACY.md.

License

chatbit is free software under the GNU General Public License v3, like the code it derives from. See LICENSE.md. The chatbit name and visuals are covered by TRADEMARKS.md.

Built on bitchat and bitchat-android. Thanks to their authors.