bitchat

Overview

A decentralized messaging app with dual transport: local Bluetooth mesh for offline communication and Nostr protocol for global reach. No accounts, no central servers, privacy-first with end-to-end encryption. Features location-based channels and IRC-style commands.

README Preview

\n\n## bitchat\n\nA 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. It's the side-groupchat.\n\n[bitchat.free](http://bitchat.free)\n\n📲 [App Store](https://apps.apple.com/us/app/bitchat-mesh/id6748219622)\n\n## License\n\nThis project is released into the public domain. See the [LICENSE](LICENSE) file for details.\n\n## Features\n\n- **Dual Transport Architecture**: Bluetooth mesh for offline + Nostr protocol for internet-based messaging\n- **Location-Based Channels**: Geographic chat rooms using geohash coordinates over global Nostr relays\n- **Intelligent Message Routing**: Automatically chooses best transport (Bluetooth → Nostr fallback)\n- **Decentralized Mesh Network**: Automatic peer discovery and multi-hop message relay over Bluetooth LE\n- **Privacy First**: No accounts, no phone numbers, no persistent identifiers\n- **Private Message End-to-End Encryption**: [Noise Protocol](https://noiseprotocol.org) for mesh, NIP-17 for Nostr\n- **IRC-Style Commands**: Familiar `/slap`, `/msg`, `/who` style interface\n- **Universal App**: Native support for iOS and macOS\n- **Emergency Wipe**: Triple-tap to instantly clear all data\n- **Performance Optimizations**: LZ4 message compression, adaptive battery modes, and optimized networking\n\n## [Technical Architecture](https://deepwiki.com/permissionlesstech/bitchat)\n\nBitChat uses a **hybrid messaging architecture** with two complementary transport layers:\n\n### Bluetooth Mesh Network (Offline)\n\n- **Local Communication**: Direct peer-to-peer within Bluetooth range\n- **Multi-hop Relay**: Messages route through nearby devices (max 7 hops)\n- **No Internet Required**: Works completely offline in disaster scenarios\n- **Noise Protocol Encryption**: End-to-end encryption with forward secrecy\n- **Binary Protocol**: Compact packet format