c5ca7a0612
Server
node/api_feed.go: new GET /feed/post/{id}/attachment route. Returns
raw attachment bytes with the correct Content-Type so React Native's
<Image source={uri}> can stream them directly without the client
fetching + decoding base64 from the main /feed/post/{id} JSON (would
blow up memory on a 40-post timeline). Respects on-chain soft-delete
(410 when tombstoned). Cache-Control: public, max-age=3600, immutable
— attachments are content-addressed so aggressive caching is safe.
PostCard — rewritten header row
- Avatar + name + time collapsed into a single Pressable row with
flexDirection:'row'. Name gets flexShrink:1 + numberOfLines:1 so
long handles truncate with "…" mid-row instead of pushing the time
onto a second line. Time and separator dot both numberOfLines:1
with no flex — they never shrink, so "2h" stays readable.
- Whole header is one tap target → navigates to the author's profile.
PostCard — body truncation
- Timeline view (compact=false): numberOfLines={5} + ellipsizeMode:
'tail'. Long posts collapse to 5 lines with "…"; tapping the card
opens the detail view where the full body is shown.
- Detail view (compact=true): no line cap — full text, then full-
size attachment below.
PostCard — real image previews
- <Image source={{ uri: `${node}/feed/post/${id}/attachment` }}>
(feed layout).
- Timeline: aspectRatio: 4/5 + resizeMode:'cover' — portrait photos
get cropped so one tall image can't eat the whole feed.
- Detail: aspectRatio: 1 + resizeMode:'contain' so the full image
fits in its original proportions (crop-free).
PostCard — comments button removed
v2.0.0 doesn't implement replies; a dead button with label "0" was
noise. Action row now has 3 cells: heart (with live like count),
eye (views), share (pinned right). Spacing stays balanced because
each of the first two cells is still flex:1.
Post detail screen
- Passes compact prop so the PostCard above renders in full-body /
full-attachment mode.
- Dropped the old AttachmentPreview placeholder — PostCard now
handles images in both modes.
Tests
- go test ./... — all 7 packages green (blockchain / consensus /
identity / media / node / relay / vm).
- tsc --noEmit on client-app — 0 errors.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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.