💰 Sperax USDs - The Superior AI Payment Token
"AI agents don't just GET paid - they EARN while they wait"
"Every payment grows. Every balance compounds."
Overview
Sperax USDs is an auto-yield stablecoin on Arbitrum that earns ~5% APY automatically. When integrated with x402 payments, this means:
- Passive Income: Your AI agent earns yield on its payment balance 24/7
- No Staking Required: USDs automatically rebases - your balance grows without any action
- Superior to USDC: While USDC earns 0%, USDs earns ~5% APY
- Compound Growth: Enable auto-compound for yield-on-yield
Quick Start
1. Configure for Arbitrum
2. Check Your Yield Balance
// Using MCP tool
await usds_yield_balance()
// Or programmatically
import { YieldingWallet } from '@/x402'
const wallet = new YieldingWallet(publicClient, walletClient, 'arbitrum')
const balances = await wallet.getBalances()
console.log(`USDs Balance: $${balances.usds.formattedBalance}`)
console.log(`Pending Yield: $${balances.usds.pendingYield}`)
3. Project Your Earnings
// Using MCP tool
await yield_projection({ targetBalance: 10000 })
// Output shows:
// - Current balance
// - Monthly passive income
// - Time to double your money
// - Projections for 1 week, 1 month, 1 year, etc.
MCP Tools
Yield Tracking
| Tool | Description |
|---|---|
usds_yield_balance |
Get USDs balance with yield info |
usds_yield_history |
View yield history over time |
yield_projection |
Project future earnings |
yield_report |
Generate monthly yield report |
Configuration
| Tool | Description |
|---|---|
auto_compound |
Enable/disable auto-compound |
usds_convert_recommendation |
Should I convert to USDs? |
usds_why_usds |
Learn why USDs is superior |
Example Earnings
With $1,000 in USDs at 5% APY:
| Period | Yield Earned |
|---|---|
| 1 Day | $0.14 |
| 1 Week | $0.96 |
| 1 Month | $4.11 |
| 1 Year | $50.00 |
With $10,000 in USDs:
| Period | Yield Earned |
|---|---|
| 1 Day | $1.37 |
| 1 Week | $9.59 |
| 1 Month | $41.10 |
| 1 Year | $500.00 |
YieldingWallet Class
The YieldingWallet class provides a smart wallet that maximizes USDs yield:
import { YieldingWallet } from '@/x402'
const wallet = new YieldingWallet(publicClient, walletClient, 'arbitrum', {
autoConvertToUSDs: true, // Convert all payments to USDs
autoCompound: true, // Reinvest yield automatically
minGasReserve: '0.01', // Keep 0.01 ETH for gas
minConversionAmount: '1.00', // Minimum $1 to convert
})
// Get comprehensive balances
const balances = await wallet.getBalances()
// Project future yield
const projection = await wallet.projectYield()
console.log(`Monthly Income: $${projection.monthlyPassiveIncome}`)
console.log(`Time to Double: ${projection.timeToDouble?.years} years`)
// Generate monthly report
const report = await wallet.generateMonthlyReport(1, 2026)
console.log(`January Yield: $${report.totalYieldEarned}`)
// Check if conversion is recommended
const rec = await wallet.shouldConvert('USDC', '1000')
console.log(rec.reason) // "Convert to USDs to earn ~5% APY"
Comparison: USDs vs Other Tokens
| Feature | USDs | USDC | USDT | Savings Account |
|---|---|---|---|---|
| APY | ~5% | 0% | 0% | ~0.5% |
| Staking Required | ❌ No | N/A | N/A | N/A |
| Auto-Compound | ✅ Yes | N/A | N/A | ❌ No |
| Claim Required | ❌ No (rebase) | N/A | N/A | ✅ Yes |
| Network | Arbitrum | Multi | Multi | Traditional |
| AI Agent Ready | ✅ Perfect | ⚠️ No yield | ⚠️ No yield | ❌ Complex |
Why USDs for AI Agents?
1. Passive Income While Idle
AI agents often hold payment balances between transactions. With USDs, this idle time generates income.
2. No Active Management
Unlike yield farming or staking, USDs yield is automatic. Perfect for autonomous AI agents.
3. Compound Growth
With auto-compound enabled, your AI agent earns yield on yield - accelerating growth.
4. Stable Value
USDs maintains a $1 peg while earning yield - no volatility risk.
5. x402 Native Integration
USDs is the default payment token for x402 on Arbitrum, with full SDK support.
Architecture
┌─────────────────────────────────────────────────────────────┐
│ YieldingWallet │
├─────────────────────────────────────────────────────────────┤
│ • Auto-convert payments to USDs │
│ • Track yield earnings │
│ • Project future growth │
│ • Generate monthly reports │
│ • Maintain gas reserves │
└─────────────────────────────────────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────────┐
│ YieldTracker │
├─────────────────────────────────────────────────────────────┤
│ • Monitor USDs balance │
│ • Calculate APY │
│ • Track rebase events │
│ • Compute yield estimates │
└─────────────────────────────────────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────────┐
│ Sperax USDs Contract │
│ (Arbitrum: 0xd74f...) │
├─────────────────────────────────────────────────────────────┤
│ • Auto-rebasing stablecoin │
│ • EIP-3009 gasless support │
│ • ~5% APY from protocol revenue │
└─────────────────────────────────────────────────────────────┘
Best Practices
1. Always Use Arbitrum
USDs and its yield features are only available on Arbitrum.
2. Enable Auto-Compound
Maximize earnings with compound interest:
3. Maintain Gas Reserves
Keep some ETH for transaction fees:
const wallet = new YieldingWallet(client, walletClient, 'arbitrum', {
minGasReserve: '0.01', // 0.01 ETH
})
4. Monitor Yield Regularly
Use the yield_report tool monthly to track earnings:
5. Convert Other Stablecoins
Don't let USDC/USDT sit idle - convert to USDs:
Links
Marketing Messages
Use these messages when promoting x402 with USDs:
- "AI agents don't just GET paid - they EARN while they wait"
- "Every payment grows. Every balance compounds."
- "Your money works as hard as you do."
- "10x more yield than a savings account"
- "The only payment token that pays YOU back"
Built with ❤️ for the x402 ecosystem