55d51ba084 DMs to unreachable peers use store-and-forward instead of failing instantly (#1415)
* DMs to unreachable peers route through store-and-forward; drop stale reachability gates

Field-found: sendPrivateMessage pre-judged reachability and marked the
message failed without ever calling the router, so the retained outbox,
courier deposits, and bridge drops never ran — a DM composed after a
peer's reachability window lapsed was dead on arrival while an identical
one sent a minute earlier delivered. Messages now always route; a live
path earns "sent", everything else stays "sending" until the router
reports carried/delivered or expires it as failed.

A sweep for sibling gates found and fixed:
- startPrivateChat refused offline non-mutual favorites ("mutual favorite
  required for offline messaging") — store-and-forward only needs the
  recipient's noise key, so the gate and its string are gone.
- markPrivateMessagesAsRead skipped the whole receipt pass for peers
  without a stored Nostr key, starving mesh-connected non-favorites; the
  router picks the transport now (sentReadReceipts dedups the parallel
  PrivateChatManager path).
- DM/geoDM blocked notices and the unknown-group error posted to the
  active public timeline; they now land in the thread they're about via
  addLocalPrivateSystemMessage.
- Banned copy: literal "user" fallbacks in code become "anon" (the
  default-nickname convention), and es/fr/it/pt translations of four keys
  still saying usuario/utilisateur/utente/usuário now say person. Orphaned
  keys removed (system.dm.unreachable, content.delivery.reason.unreachable,
  system.chat.requires_favorite).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Deflake BLEServiceCoreTests: longTimeout for positive waits

CI flaked on duplicatePacket_isDeduped: the first message landed after the
5s wait expired on a loaded runner (the test's later count==1 assertions
passed, proving late delivery, not lost delivery). All four positive waits
in the file now use TestConstants.longTimeout, which exists for exactly
this — waitUntil returns as soon as the condition holds, so passing runs
never pay the longer ceiling.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Fix read-receipt test contamination; baseline Periphery noiseKey flake

Two CI failures, both environmental:

- markReadReceiptSent_returnsFalseOnSecondCall flaked because every test
  ChatViewModel shared one per-process read-receipts scratch suite; the
  lifecycle test persists the same "read-1" ID (a path the receipt-gate
  removal now reaches), and test order decided who saw whose state. Each
  instance now gets its own UUID-suffixed suite.

- Periphery intermittently misses the loadFromDisk read of
  PrekeyBundleStore.StoredBundle.noiseKey and fails --strict with a false
  "assign-only" finding (recurrence of a known flake). Its USR is
  baselined; an in-source periphery:ignore can't work because strict mode
  flags it as superfluous on runs where the indexer gets it right.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-08 22:42:39 +02:00
2026-07-07 21:09:17 +02:00
2026-04-05 19:04:18 -05:00
2026-01-14 14:39:39 -10:00

icon_128x128@2x

bitchat

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. It's the side-groupchat.

bitchat.free

📲 App Store

License

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

Features

  • Dual Transport Architecture: Bluetooth mesh for offline + Nostr protocol for internet-based messaging
  • Location-Based Channels: Geographic chat rooms using geohash coordinates over global Nostr relays
  • Intelligent Message Routing: Automatically chooses best transport (Bluetooth → Nostr fallback)
  • Decentralized Mesh Network: Automatic peer discovery and multi-hop message relay over Bluetooth LE
  • Privacy First: No accounts, no phone numbers, no persistent identifiers
  • Private Message End-to-End Encryption: Noise Protocol for mesh, NIP-17 for Nostr
  • IRC-Style Commands: Familiar /slap, /msg, /who style interface
  • Universal App: Native support for iOS and macOS
  • Emergency Wipe: Triple-tap to instantly clear all data
  • Performance Optimizations: LZ4 message compression, adaptive battery modes, and optimized networking

Technical Architecture

BitChat uses a hybrid messaging architecture with two complementary transport layers:

Bluetooth Mesh Network (Offline)

  • Local Communication: Direct peer-to-peer within Bluetooth range
  • Multi-hop Relay: Messages route through nearby devices (max 7 hops)
  • No Internet Required: Works completely offline in disaster scenarios
  • Noise Protocol Encryption: End-to-end encryption with forward secrecy
  • Binary Protocol: Compact packet format optimized for Bluetooth LE constraints
  • Automatic Discovery: Peer discovery and connection management
  • Adaptive Power: Battery-optimized duty cycling

Nostr Protocol (Internet)

  • Global Reach: Connect with users worldwide via internet relays
  • Location Channels: Geographic chat rooms using geohash coordinates
  • 290+ Relay Network: Distributed across the globe for reliability
  • NIP-17 Encryption: Gift-wrapped private messages for internet privacy
  • Ephemeral Keys: Fresh cryptographic identity per geohash area

Channel Types

mesh #bluetooth

  • Transport: Bluetooth Low Energy mesh network
  • Scope: Local devices within multi-hop range
  • Internet: Not required
  • Use Case: Offline communication, protests, disasters, remote areas

Location Channels (block #dr5rsj7, neighborhood #dr5rs, country #dr)

  • Transport: Nostr protocol over internet
  • Scope: Geographic areas defined by geohash precision
    • block (7 chars): City block level
    • neighborhood (6 chars): District/neighborhood
    • city (5 chars): City level
    • province (4 chars): State/province
    • region (2 chars): Country/large region
  • Internet: Required (connects to Nostr relays)
  • Use Case: Location-based community chat, local events, regional discussions

Direct Message Routing

Private messages use intelligent transport selection:

  1. Bluetooth First (preferred when available)

    • Direct connection with established Noise session
    • Fastest and most private option
  2. Nostr Fallback (when Bluetooth unavailable)

    • Uses recipient's Nostr public key
    • NIP-17 gift-wrapping for privacy
    • Routes through global relay network
  3. Smart Queuing (when neither available)

    • Messages queued until transport becomes available
    • Automatic delivery when connection established

For detailed protocol documentation, see the Technical Whitepaper.

Setup

Option 1: Using Xcode

cd bitchat
open bitchat.xcodeproj

To run on a device there're a few steps to prepare the code:

  • Clone the local configs: cp Configs/Local.xcconfig.example Configs/Local.xcconfig
  • Add your Developer Team ID into the newly created Configs/Local.xcconfig
    • Bundle ID would be set to chat.bitchat.<team_id> (unless you set to something else)
  • Entitlements need to be updated manually (TODO: Automate):
    • Search and replace group.chat.bitchat with group.<your_bundle_id> (e.g. group.chat.bitchat.ABC123)

Option 2: Using just

brew install just

Want to try this on macos: just run will set it up and run from source. Run just clean afterwards to restore things to original state for mobile app building and development.

Localization

  • Base app resources live under bitchat/Localization/Base.lproj/. Add new copy to Localizable.strings and plural rules to Localizable.stringsdict.
  • Share extension strings are separate in bitchatShareExtension/Localization/Base.lproj/Localizable.strings.
  • Prefer keys that describe intent (app_info.features.offline.title) and reuse existing ones where possible.
  • Run xcodebuild -project bitchat.xcodeproj -scheme "bitchat (macOS)" -configuration Debug CODE_SIGNING_ALLOWED=NO build to compile-check any localization updates.
S
Description
bluetooth mesh chat, IRC vibes
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