423d307125
PR #2 of the multi-device roadmap — wires the messenger pipeline against the on-chain registry landed in v2.2.0-alpha1. lib/api.ts: - DeviceInfo type mirroring blockchain.DeviceInfo. - IdentityInfo.device_count (optional; populated from /api/identity). - fetchDevices(masterPub) → /api/devices/{master_pub}, returns []. Errors swallowed so a downed endpoint doesn't block messaging. - resolveRecipientKeys(masterPub) — the routing primitive. Returns devices[] if registered, else falls back to IdentityInfo.x25519_pub (pre-v2.2.0 path). Empty only when recipient has published nothing. - buildLinkDeviceTx / buildUnlinkDeviceTx — signed by master Ed25519, min-fee cost, canonical JSON payload matching the chain-side LinkDevicePayload / UnlinkDevicePayload. app/(app)/chats/[id].tsx: - sendCore now fans out: encrypts once per recipient device pub (Promise.all, any failure rejects the batch), falls back to the cached contact.x25519Pub if the registry lookup returns nothing. - Saved Messages short-circuit preserved; no devices lookup for self. app/(app)/_layout.tsx: - On every sign-in, auto-submit LINK_DEVICE for this device if its X25519 pub isn't already in the master's registry. Device name picks "iPhone" / "Android phone" / "Device" by Platform. Errors (insufficient balance / legacy chain without LINK_DEVICE support) are silent — next launch retries. Backward compatibility: senders fall back to identity.x25519_pub when the recipient has no registry entries, so pre-v2.2.0 clients still receive messages. Chain-side already gates new validation on the event types existing; old clients simply never emit LINK_DEVICE and keep working with a single X25519. Next — PR #3 (Settings → Devices screen + QR pairing flow + receive-side self-wipe on revoke detection).
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.