Two coordinated changes:
1. Desktop client gets a functional Messages section and working pairing
flow, putting it at feature parity with mobile for the v2.2.0 line.
2. Server + both clients teach each other to use the sender's master
Ed25519 (not just their X25519) to address conversations, so a peer
writing from a different linked device still rolls into the same chat.
This is the "new API logic" the desktop scaffold was waiting on.
Server (node/api_relay.go, cmd/node/main.go):
* /relay/inbox items now carry `sender_ed25519_pub` alongside the
per-device `sender_pub`. Empty string for pre-v2.2.0 senders.
* WS `inbox` push summary also includes `sender_ed25519_pub`, so the
client can skip the refetch when the envelope plainly isn't for
the chat they're watching.
* Both existing tests pass.
Mobile client:
* lib/types.ts Envelope grew `sender_ed25519_pub`; fetchInbox normalises
it (default '') for older nodes.
* hooks/useGlobalInbox matches contacts by (master Ed25519 OR legacy
X25519) so an incoming message from a peer's desktop reuses the
existing chat instead of creating a duplicate placeholder.
* hooks/useMessages now takes an optional `contactMasterEd25519` and
exposes a matchesChat() predicate; WS inbox handler uses it too to
avoid spurious refetches.
* chats/[id].tsx passes `contact.address` (master) along with x25519.
Desktop client — all new:
* src/lib/crypto.ts — tweetnacl hex/base64 helpers, generateKeyFile,
encryptMessage/decryptMessage, signBase64, shortAddr. Same signatures
as the mobile lib; uses Chromium's window.crypto, no expo-crypto dep.
* src/lib/tx.ts — buildTransferTx / buildLinkDeviceTx / buildUnlinkDeviceTx
+ submitTx + humanizeTxError, canonical-bytes identical to mobile.
* src/lib/relay.ts — fetchInbox, sendEnvelope, resolveRecipientKeys
(multi-device fan-out with legacy identity.x25519 fallback).
* src/lib/store.ts — zustand state gets messages{}, unread{},
activeChat.
* src/lib/storage.ts — per-chat cache via localStorage (500-msg cap).
* src/hooks/useInboxPoll — 4s polling loop, addresses conversations
by master Ed25519, bumps unread unless chat is active.
* src/sections/messages/* — ChatList (sorted tiles, unread badges),
Conversation (auto-scroll messages + composer + fan-out send,
Enter-to-send / Shift+Enter for newline), EmptyConversation.
* src/auth/Pair.tsx — 6-digit code + device key screen, polls inbox
for a handshake envelope, assembles the KeyFile on arrival.
* Welcome.tsx: Pair button now actually routes to <Pair>; imports
generateKeyFile from lib/crypto (was inlined).
docs/ROADMAP.md delta: alpha5 row flipped to done inline. Alpha6
(feed + wallet) and rc1 (contacts + devices UI + profile) still
pending.
DChain Messenger — React Native Client
E2E-encrypted mobile/desktop messenger built on the DChain blockchain stack.
Stack: React Native · Expo · NativeWind (Tailwind) · TweetNaCl · Zustand
Quick Start
cd client-app
npm install
npx expo start # opens Expo Dev Tools
# Press 'i' for iOS simulator, 'a' for Android, 'w' for web
Requirements
- Node.js 18+
- Expo Go on your phone (for Expo tunnel), or iOS/Android emulator
- A running DChain node (see root README for
docker compose up --build -d)
Project Structure
client-app/
├── app/
│ ├── _layout.tsx # Root layout — loads keys, sets up nav
│ ├── index.tsx # Welcome / onboarding
│ ├── (auth)/
│ │ ├── create.tsx # Generate new Ed25519 + X25519 keys
│ │ ├── created.tsx # Key created — export reminder
│ │ └── import.tsx # Import existing key.json
│ └── (app)/
│ ├── _layout.tsx # Tab bar — Chats · Wallet · Settings
│ ├── chats/
│ │ ├── index.tsx # Chat list with contacts
│ │ └── [id].tsx # Individual chat with E2E encryption
│ ├── requests.tsx # Incoming contact requests
│ ├── new-contact.tsx # Add contact by @username or address
│ ├── wallet.tsx # Balance + TX history + send
│ └── settings.tsx # Node URL, key export, profile
├── components/ui/ # shadcn-style components (Button, Card, Input…)
├── hooks/
│ ├── useMessages.ts # Poll relay inbox, decrypt messages
│ ├── useBalance.ts # Poll token balance
│ └── useContacts.ts # Load contacts + poll contact requests
└── lib/
├── api.ts # REST client for all DChain endpoints
├── crypto.ts # NaCl box encrypt/decrypt, Ed25519 sign
├── storage.ts # SecureStore (keys) + AsyncStorage (data)
├── store.ts # Zustand global state
├── types.ts # TypeScript interfaces
└── utils.ts # cn(), formatAmount(), relativeTime()
Cryptography
| Operation | Algorithm | Library |
|---|---|---|
| Transaction signing | Ed25519 | TweetNaCl sign |
| Key exchange | X25519 (Curve25519) | TweetNaCl box |
| Message encryption | NaCl box (XSalsa20-Poly1305) | TweetNaCl box |
| Key storage | Device secure enclave | expo-secure-store |
Messages are encrypted as:
Envelope {
sender_pub: <X25519 hex> // sender's public key
recipient_pub: <X25519 hex> // recipient's public key
nonce: <24-byte hex> // random per message
ciphertext: <hex> // NaCl box(plaintext, nonce, sender_priv, recipient_pub)
}
Connect to your node
- Start the DChain node:
docker compose up --build -d - Open the app → Settings → Node URL →
http://YOUR_IP:8081 - If using Expo Go on physical device: your PC and phone must be on the same network, or use
npx expo start --tunnel
Key File Format
The key.json exported/imported by the app:
{
"pub_key": "26018d40...", // Ed25519 public key (64 hex chars)
"priv_key": "...", // Ed25519 private key (128 hex chars)
"x25519_pub": "...", // X25519 public key (64 hex chars)
"x25519_priv": "..." // X25519 private key (64 hex chars)
}
This is the same format as the Go node's --key flag.