Data Persistence

KayakNet persists all data locally to survive restarts and provide history.

Data Directory

Default location: ./data/

data/
├── identity.key          # Node identity (Ed25519 keypair)
├── peers.json            # Known peer addresses
├── config.json           # Runtime configuration
├── dht/
│   └── records.json      # DHT records
├── chat/
│   ├── rooms/
│   │   └── #general.json # Room messages
│   └── dms/
│       └── <node_id>.json # Direct messages
├── market/
│   ├── listings.json     # All listings
│   └── my_listings.json  # Your listings
├── escrow/
│   ├── orders.json       # Order records
│   └── wallets.json      # Crypto wallet data
├── names/
│   └── domains.json      # .kyk registrations
└── cache/
    └── ...               # Temporary cache

Identity Persistence

identity.key

{
  "private_key": "<base64 encoded Ed25519 private key>",
  "public_key": "<base64 encoded public key>",
  "node_id": "<hex encoded node ID>",
  "created_at": "2026-01-15T10:00:00Z"
}

Important:

• Back this up!

• Losing it = new identity

• Never share with anyone

Chat Persistence

Room Messages

data/chat/rooms/#general.json:

{
  "room": "#general",
  "messages": [
    {
      "id": "msg_abc123",
      "sender_id": "node_123...",
      "sender_name": "alice",
      "content": "Hello!",
      "timestamp": 1234567890,
      "signature": "..."
    }
  ],
  "last_sync": "2026-01-15T10:00:00Z"
}

Direct Messages

data/chat/dms/<recipient_id>.json:

{
  "peer_id": "node_456...",
  "peer_name": "bob",
  "messages": [
    {
      "id": "dm_xyz789",
      "from_me": true,
      "content": "Private message",
      "timestamp": 1234567890,
      "read": true
    }
  ]
}

Marketplace Persistence

Listings

data/market/listings.json:

{
  "listings": [
    {
      "id": "listing_abc",
      "title": "Product",
      "price": 99.99,
      "seller_id": "node_123...",
      "created_at": "2026-01-15T10:00:00Z",
      "synced_at": "2026-01-15T10:05:00Z"
    }
  ]
}

Escrow Persistence

Orders

data/escrow/orders.json:

{
  "orders": [
    {
      "id": "esc_123",
      "order_id": "ord_456",
      "listing_id": "listing_abc",
      "buyer_id": "node_buyer...",
      "seller_id": "node_seller...",
      "amount": 0.5,
      "currency": "XMR",
      "state": "funded",
      "payment_address": "...",
      "created_at": "2026-01-15T10:00:00Z"
    }
  ]
}

Domain Persistence

Registered Domains

data/names/domains.json:

{
  "domains": [
    {
      "name": "mysite.kyk",
      "target": "node_id:abc123...",
      "owner": "<public_key>",
      "registered_at": "2026-01-15T10:00:00Z",
      "signature": "..."
    }
  ]
}

Sync Mechanism

On Startup

1. Load local data from files

2. Connect to network

3. Request updates from peers

4. Merge with local data

5. Save merged state

During Runtime

• Changes saved immediately

• Background sync every 5 minutes

• Conflict resolution by timestamp

Conflict Resolution

• Newer timestamp wins

• For listings: Seller's version wins

• For domains: First registration wins

Backup & Recovery

Creating Backup

# Backup entire data directory
tar -czf kayaknet-backup.tar.gz ./data/

# Or just identity
cp data/identity.key identity-backup.key

Restoring Backup

# Full restore
tar -xzf kayaknet-backup.tar.gz

# Identity only
cp identity-backup.key data/identity.key

What to Backup

File	Priority	Notes
identity.key	Critical	Cannot recover
names/domains.json	High	Your domains
escrow/orders.json	High	Transaction records
chat/	Medium	Message history
market/my_listings.json	Medium	Your listings
peers.json	Low	Rebuilds quickly

Storage Limits

Default Limits

Data Type	Limit
Chat messages per room	10,000
DM conversations	1,000
Listings cache	5,000
DHT records	10,000

Cleanup

Old data is automatically cleaned:

• Expired DHT records: Deleted on expiry

• Old messages: Keep last N

• Failed escrows: Archive after 30 days

Custom Data Directory

./kayakd --data-dir /custom/path/data

Or environment variable:

export KAYAKNET_DATA_DIR=/custom/path/data

Database Format

Currently using JSON files for simplicity.

Future plans:

• SQLite for large datasets

• LevelDB for DHT

• Encrypted storage option