# Sperax Protocol Documentation
Complete technical specifications for the Sperax DeFi protocol ecosystem.
**Last Updated**: January 2026
**Primary Chain**: Arbitrum One (Chain ID: 42161)
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## 📖 Documentation
<div class="grid cards" markdown>
- :material-file-document:{ .lg .middle } **Overview**
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Protocol architecture and yield flow
[:octicons-arrow-right-24: Read Overview](overview.md)
- :material-currency-usd:{ .lg .middle } **USDs Token**
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Auto-yield stablecoin and rebase mechanics
[:octicons-arrow-right-24: USDs Docs](usds-token.md)
- :material-safe-square-outline:{ .lg .middle } **Vault Core**
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Mint, redeem, and collateral management
[:octicons-arrow-right-24: Vault Docs](vault-core.md)
- :material-database-cog:{ .lg .middle } **Collateral Manager**
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Collateral configuration and fees
[:octicons-arrow-right-24: Collateral Docs](collateral-manager.md)
- :material-chart-line:{ .lg .middle } **Strategies**
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Aave, Compound, Stargate yield strategies
[:octicons-arrow-right-24: Strategies](strategies.md)
- :material-water-outline:{ .lg .middle } **Rebase Dripper**
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RebaseManager and Dripper contracts
[:octicons-arrow-right-24: Dripper Docs](rebase-dripper.md)
- :material-chart-bubble:{ .lg .middle } **Oracles**
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MasterPriceOracle, Chainlink, DIA, TWAP
[:octicons-arrow-right-24: Oracle Docs](oracles.md)
- :material-swap-horizontal:{ .lg .middle } **SPA Buyback**
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SPABuyback and YieldReserve
[:octicons-arrow-right-24: Buyback Docs](spa-buyback.md)
- :material-lock-outline:{ .lg .middle } **SPA Staking**
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SPA, veSPA, xSPA tokenomics
[:octicons-arrow-right-24: Staking Docs](spa-staking.md)
- :material-tractor:{ .lg .middle } **Demeter Farms**
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Farm contracts and registry
[:octicons-arrow-right-24: Farm Docs](demeter-farms.md)
- :material-gift-outline:{ .lg .middle } **Rewarder**
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APR-based reward distribution
[:octicons-arrow-right-24: Rewarder Docs](rewarder.md)
- :material-map-marker:{ .lg .middle } **Addresses**
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All deployed contract addresses
[:octicons-arrow-right-24: Addresses](addresses.md)
- :material-alert-circle-outline:{ .lg .middle } **Errors & Events**
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Complete error and event reference
[:octicons-arrow-right-24: Reference](errors-events.md)
</div>
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## 🔗 Quick Links
### Official Resources
- **Website**: https://sperax.io
- **dApp**: https://app.sperax.io
- **Docs**: https://docs.sperax.io
- **GitHub**: https://github.com/Sperax
### Source Repositories
- [Sperax/USDs-v2](https://github.com/Sperax/USDs-v2) - Core USDs Protocol
- [Sperax/Demeter-Protocol-Contracts](https://github.com/Sperax/Demeter-Protocol-Contracts) - Yield Farming
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## 🎯 Key Contract Addresses (Arbitrum)
| Contract | Address |
|----------|---------|
| USDs | `0xD74f5255D557944cf7Dd0E45FF521520002D5748` |
| SPA | `0x5575552988A3A80504bBaeB1311674fCFd40aD4B` |
| veSPA | `0x2e2071180682Ce6C247B1eF93d382D509F5F6A17` |
| xSPA | `0x0966E72256d6055145902F72F9D3B6a194B9cCc3` |
| Vault | `0x6Bbc476Ee35CBA9e9c3A59fc5b10d7a0BC6f74Ca` |
| SPABuyback | `0xFbc0d3cA777722d234FE01dba94DeDeDb277AFe3` |
| Farm Registry | `0x45bC6B44107837E7aBB21E2CaCbe7612Fce222e0` |
| MasterPriceOracle | `0x14D99412dAB1878dC01Fe7a1664cdE85896e8E50` |
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## 📐 Key Formulas
```solidity
// veSPA calculation
veSPA = SPA_staked × (lockup_days / 365)
// Lock range: 7 days to 4 years (1461 days)
// xSPA redemption (15-180 day vesting)
SPA_received = xSPA_amount × (vesting_days + 150) / 330
// 15 days = 50%, 180 days = 100%
// USDs auto-yield
yield_to_holders = collateral_yield × 0.70
yield_to_buyback = collateral_yield × 0.30
// Capped at 25% APR to holders
// Rebase formula
new_balance = credit_balance / credits_per_token
// credits_per_token decreases as yield accrues
```
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## 🏗️ Architecture Diagram
```
┌─────────────────────────────────────────────────────────────────┐
│ USER LAYER │
├─────────────────────────────────────────────────────────────────┤
│ Mint USDs Redeem USDs Stake SPA Create Farm │
└──────┬──────────────┬─────────────┬────────────┬────────────────┘
│ │ │ │
▼ ▼ ▼ ▼
┌──────────────────────────────────────────────────────────────────┐
│ CORE CONTRACTS │
├──────────────┬──────────────┬──────────────┬─────────────────────┤
│ VaultCore │ USDs │ veSPA │ FarmRegistry │
│ (Mint/ │ (Rebase │ (Vote │ (Deploy │
│ Redeem) │ Token) │ Escrow) │ Farms) │
└──────┬───────┴──────┬───────┴──────┬───────┴─────────┬───────────┘
│ │ │ │
▼ ▼ ▼ ▼
┌──────────────────────────────────────────────────────────────────┐
│ INFRASTRUCTURE │
├──────────────┬──────────────┬──────────────┬─────────────────────┤
│ Collateral │ Rebase │ SPA │ Rewarder │
│ Manager │ Manager │ Buyback │ Factory │
├──────────────┼──────────────┼──────────────┼─────────────────────┤
│ Fee │ Dripper │ Yield │ Farm │
│ Calculator │ │ Reserve │ Deployers │
└──────┬───────┴──────────────┴──────┬───────┴─────────────────────┘
│ │
▼ ▼
┌──────────────────────────────────────────────────────────────────┐
│ YIELD STRATEGIES │
├──────────────┬──────────────┬──────────────┬─────────────────────┤
│ Aave │ Compound │ Stargate │ Fluid │
│ Strategy │ Strategy │ Strategy │ Strategy │
└──────────────┴──────────────┴──────────────┴─────────────────────┘
```
