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Architecture

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System Overview

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Smart Contracts

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Vault Contract (vault.cairo)

// Assets
underlying_asset: wBTC
collateral_asset: USDC
total_wbtc_held: u256  // wBTC kept for LONG exposure

// Queue system
deposit_queue_head/tail: u256
withdrawal_queue_head/tail: u256
pending_deposits: Map<u256, DepositRequest>
pending_withdrawals: Map<u256, WithdrawalRequest>

fn deposit(wbtc_amount, min_shares, avnu_calldata) -> request_id
fn request_withdraw(shares, min_assets) -> request_id
fn complete_withdrawal(request_id, avnu_calldata)
fn process_deposits(count)  // Operator only
fn mark_withdrawal_ready(request_id, usdc_amount)  // Operator only

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Backend Services

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DepositProcessor (deposit_processor.py)

1. Reads deposit queue from contract
2. For each unprocessed deposit:
   • Calls process_deposits() (mints shares, transfers USDC)
   • Deposits USDC to Extended
   • Opens SHORT position

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WithdrawalProcessor (withdrawal_processor.py)

1. Detects PENDING withdrawals
2. Calculates USDC value of shares
3. Closes proportional position on Extended
4. Requests USDC withdrawal from Extended
5. Calls mark_withdrawal_ready() when USDC arrives

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PositionManager (position_manager.py)

• Checks funding rate
• Closes positions if funding < -0.01%
• Reopens when funding recovers
• Monitors margin ratio for liquidation risk

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NAVReporter (nav_reporter.py)

• Calculates: wBTC value + Extended equity
• Signs NAV update
• Submits to vault contract

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API Endpoints

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External Integrations

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Extended Exchange

• Deposit contract: 0x062da0780fae...
• Funding payments every hour
• Formula: Position × Price × Rate

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AVNU Router

• Address: 0x04270219d365d6...
• Used for wBTC ↔ USDC swaps on deposit/withdrawal

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Data Flow

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Deposit

User wBTC → Vault (keep 50%) → AVNU (swap 50%) → 
Backend → Extended deposit → Open SHORT

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Yield Generation

Every hour: Extended calculates funding
If rate > 0: Shorts receive payment → Equity grows

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Withdrawal

Close SHORT → Withdraw USDC from Extended →
Vault swaps to wBTC → Combine with vault wBTC → User

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Security Model