// Example: DeFi Smart Contract with Hybrid Trust
// This demonstrates the language's capabilities for building decentralized applications
// that integrate with centralized services
@trust("hybrid")
@chain("ethereum")
@advanced_security("strict")
@secure
service DeFiProtocol {
// State variables
total_supply: int;
balances: map<string, int>;
oracle_feeds: map<string, OracleFeed>;
admin_addresses: set<string>;
// Events
event Transfer(from: string, to: string, amount: int);
event PriceUpdate(asset: string, price: int);
event AdminAction(admin: string, action: string);
}
@txn
@limit(10000)
fn initialize_protocol() -> bool {
// Initialize the protocol with basic parameters
let admin = auth::session().user_id;
if (!auth::has_role(auth::session(), "admin") ) {
log::error("Unauthorized initialization attempt", {
"user": admin,
"required_role": "admin"
});
return false;
}
// Set up oracle feeds for price data
let btc_feed = oracle::create_source("bitcoin_price", "https://api.coingecko.com/api/v3/simple/price");
let eth_feed = oracle::create_source("ethereum_price", "https://api.coingecko.com/api/v3/simple/price");
// Initialize balances
balances["admin"] = 1000000; // 1M tokens to admin
total_supply = 1000000;
log::audit("protocol_initialized", {
"admin": admin,
"total_supply": total_supply,
"timestamp": timestamp()
});
true
}
@txn
@secure
fn transfer(from: string, to: string, amount: int) -> bool {
// Transfer tokens between addresses
if (amount <= 0 ) {
log::warning("Invalid transfer amount", { "amount": amount });
return false;
}
if (balances[from] < amount ) {
log::error("Insufficient balance", {
"from": from,
"balance": balances[from],
"amount": amount
});
return false;
}
// Perform the transfer
balances[from] = balances[from] - amount;
balances[to] = balances[to] + amount;
// Emit transfer event
event Transfer { from: from, to: to, amount: amount };
log::audit("transfer_executed", {
"from": from,
"to": to,
"amount": amount,
"new_balance_from": balances[from],
"new_balance_to": balances[to]
});
true
}
@trust("hybrid")
@chain("ethereum")
@secure
fn get_asset_price(asset: string) -> int {
// Get current price from oracle with fallback to centralized API
let oracle_query = oracle::create_query(asset + "_price");
let response = oracle::fetch("price_feed", oracle_query);
let price = response.data;
return price;
}
@txn
@limit(5000)
fn create_liquidity_pool(asset: string, initial_amount: int) -> bool {
// Create a new liquidity pool for an asset
let admin = auth::session().user_id;
if (!auth::has_role(auth::session(), "admin") ) {
log::error("Unauthorized pool creation", { "user": admin });
return false;
}
// Validate initial amount
if (initial_amount <= 0 ) {
log::error("Invalid initial amount", { "amount": initial_amount });
return false;
}
// Get current asset price
let asset_price = get_asset_price(asset);
if (asset_price <= 0 ) {
log::error("Invalid asset price", { "asset": asset, "price": asset_price });
return false;
}
// Calculate pool tokens to mint
let pool_tokens = initial_amount * asset_price / 1000; // Simplified calculation
// Mint pool tokens
let pool_id = chain::mint("pool_" + asset, {
"asset": asset,
"initial_amount": initial_amount,
"pool_tokens": pool_tokens,
"created_by": admin,
"created_at": timestamp()
});
log::audit("liquidity_pool_created", {
"pool_id": pool_id,
"asset": asset,
"initial_amount": initial_amount,
"pool_tokens": pool_tokens,
"admin": admin
});
event AdminAction { admin: admin, action: "create_pool" };
true
}
@secure
fn sync_with_external_system() -> bool {
// Synchronize data with external centralized system
let sync_target = sync::create_sync_target("https://api.defi-protocol.com/sync", "http")
.with_credentials({
"api_key": "your_api_key_here",
"api_secret": "your_api_secret_here"
});
let sync_data = {
"total_supply": total_supply,
"active_users": balances.len(),
"last_updated": timestamp()
};
let result = sync::push(sync_data, sync_target);
log::info("Data synchronized", { "timestamp": timestamp() });
return true;
}
@txn
@limit(1000)
fn emergency_pause() -> bool {
// Emergency pause functionality
let admin = auth::session().user_id;
if (!auth::has_role(auth::session(), "super_admin") ) {
log::error("Unauthorized emergency pause", { "user": admin });
return false;
}
// Pause all operations
log::audit("emergency_pause_activated", {
"admin": admin,
"timestamp": timestamp(),
"reason": "emergency_pause"
});
event AdminAction { admin: admin, action: "emergency_pause" };
// Notify external systems
let webhook_config = service::create_webhook("https://alerts.defi-protocol.com/emergency", "POST");
let alert_data = {
"action": "emergency_pause",
"admin": admin,
"timestamp": timestamp(),
"severity": "critical"
};
let result = service::webhook(webhook_config, alert_data);
log::info("Emergency alert sent", { "admin": admin });
true
}
// Main function to demonstrate the protocol
fn main() {
log::info("DeFi Protocol starting", { "version": "1.0.0" });
// Initialize the protocol
if (!initialize_protocol() ) {
log::error("Failed to initialize protocol", {});
return;
}
// Create a liquidity pool
if (create_liquidity_pool("BTC", 1000) ) {
log::info("BTC liquidity pool created", { "amount": 1000 });
}
// Perform some transfers
if (transfer("admin", "user1", 10000) ) {
log::info("Transfer completed", { "from": "admin", "to": "user1", "amount": 10000 });
}
if (transfer("admin", "user2", 5000) ) {
log::info("Transfer completed", { "from": "admin", "to": "user2", "amount": 5000 });
}
// Get current prices
let btc_price = get_asset_price("BTC");
let eth_price = get_asset_price("ETH");
log::info("Current prices", {
"BTC": btc_price,
"ETH": eth_price
});
// Sync with external system
if (sync_with_external_system() ) {
log::info("External sync completed", {});
}
log::info("DeFi Protocol demo completed", {
"total_transfers": 2,
"pools_created": 1,
"price_queries": 2
});
}