💰Making Payments

This guide walks you through making your first autonomous payment and understanding the payment process.

Quick Start

1. Connect Your Wallet

First, connect a Web3 wallet:

• Click "Connect Wallet" button

• Choose MetaMask, Coinbase Wallet, or another provider

• Approve the connection

2. Make a Request

Tell Yuki402 what you need:

"Get me weather data for San Francisco"

3. Review Payment

Yuki402 will show you:

Found: WeatherAPI Premium
Cost: 0.001 SOL (~$2.50)
✓ Within spending limits

4. Automatic Processing

Payment happens automatically:

• Transaction submitted

• Confirmed in ~2 seconds

• Service accessed

• Data delivered

Detailed Payment Flow

Step 1: Service Discovery

When you make a request, Yuki402:

1. Parses your intent: Understands what service you need

2. Queries x402 Registry: Finds compatible services

3. Checks availability: Ensures service is online

4. Retrieves pricing: Gets current cost

Step 2: Pre-Flight Checks

Before processing payment:

Checking:
✓ Wallet connected
✓ Sufficient balance (0.01 SOL available)
✓ Within daily limit (0.003/0.01 SOL used)
✓ Within weekly limit (0.015/0.05 SOL used)
✓ Within monthly limit (0.08/0.2 SOL used)
✓ Service verified

Step 3: Transaction Construction

Yuki402 builds the transaction:

{
  to: servicePaymentAddress,
  value: "0.001 SOL",
  data: paymentProofData,
  gas: estimatedGas,
  nonce: nextNonce
}

Step 4: Signing & Submission

Your wallet automatically:

• Signs the transaction

• Submits to blockchain

• Returns transaction hash

Step 5: Confirmation

Wait for blockchain confirmation:

Transaction: 0x1234...
Status: Pending...
Block: Waiting...
───────────────────
✓ Confirmed in block 12345678
✓ 2.1 seconds elapsed

Step 6: Service Access

With payment confirmed:

1. Yuki402 retries service request

2. Includes payment proof in headers

3. Service validates payment

4. Returns requested data

Payment Methods

Native Tokens

Pay with blockchain's native currency:

Ethereum

Amount: 0.001 SOL
Gas: ~0.00015 SOL
Total: 0.00115 SOL

Solana

Amount: 0.01 SOL
Gas: ~0.000005 SOL
Total: 0.010005 SOL

ERC20 Tokens

Pay with stablecoins or other tokens:

USDC

Amount: 2.50 USDC
Gas: 0.00015 SOL
Note: Gas still paid in native token

Automatic Chain Selection

Yuki402 automatically uses the correct chain:

• Service specifies accepted chains

• Yuki402 selects cheapest/fastest

• Prompts wallet to switch if needed

Understanding Costs

Service Fee

What the service charges:

Base Price: 0.001 SOL
Per-request fee determined by service

Gas Fee

Blockchain transaction cost:

Gas Price: 20 gwei
Gas Limit: 21,000
Total Gas: 0.00042 SOL

Varies by:
- Network congestion
- Transaction complexity
- Chain (Ethereum > Polygon)

Total Cost

Service Fee:  0.001 SOL
Gas Fee:      0.00042 SOL
──────────────────────
Total:        0.00142 SOL

Payment Examples

Example 1: Simple Data Request

User: "Get current Bitcoin price"

Yuki402:
  Service: CoinGecko API
  Cost: 0.0005 SOL
  Processing...
  ✓ Transaction: 0xabc...
  ✓ Confirmed

  Bitcoin: $42,150.23
  24h Change: +2.5%

Example 2: AI Image Generation

User: "Generate an image of a sunset"

Yuki402:
  Service: Heurist Mesh
  Cost: 0.002 SOL
  Processing...
  ✓ Transaction: 0xdef...
  ✓ Confirmed
  ✓ Generating...

  [Image displayed]
  Download: sunset_001.png

Example 3: File Storage

User: "Pin this file to IPFS"

Yuki402:
  Service: Pinata
  Cost: 0.001 SOL
  File size: 2.5 MB
  Processing...
  ✓ Transaction: 0xghi...
  ✓ Confirmed
  ✓ Uploading...

  IPFS Hash: Qm...
  Gateway URL: https://...

Payment Status

Pending

⏳ Transaction submitted
   Hash: 0x1234...
   Status: Pending
   Time: 3 seconds

What's happening: Transaction in mempool, waiting for miners

Confirming

🔄 Transaction confirming
   Hash: 0x1234...
   Block: 12345678
   Confirmations: 1/3

What's happening: Included in block, waiting for more confirmations

Completed

✅ Payment successful
   Hash: 0x1234...
   Block: 12345678
   Cost: 0.00142 SOL

What's happening: Payment confirmed, service accessed

Failed

❌ Transaction failed
   Hash: 0x1234...
   Reason: Gas too low

What's happening: Transaction reverted, funds returned

Handling Issues

Insufficient Balance

❌ Cannot process payment
   Required: 0.01 SOL
   Balance: 0.005 SOL

Action: Add 0.005+ SOL to wallet

Gas Price Spike

⚠️  High gas prices detected
   Normal: $1-2
   Current: $15

Continue anyway? [Yes] [No] [Wait]

Service Unavailable

❌ Service temporarily unavailable
   Service: WeatherAPI
   Status: 503

⟳ Retry in 30 seconds? [Yes] [No]

Limit Exceeded

❌ Daily spending limit exceeded
   Limit: 0.01 SOL
   Spent: 0.01 SOL
   Attempted: 0.002 SOL

Options:
- Wait until tomorrow
- Increase limit
- Use different wallet

Best Practices

Before Making Payments

1. Verify Service: Check if service is verified in registry

2. Check Price: Ensure cost is reasonable

3. Review Limits: Confirm within your spending limits

4. Check Balance: Ensure sufficient funds + gas buffer

During Payment

1. Don't Close: Keep browser open during transaction

2. Wait for Confirmation: Don't retry immediately

3. Check Status: Monitor transaction hash on explorer

After Payment

1. Verify Receipt: Check transaction on block explorer

2. Save Hash: Keep transaction hash for records

3. Review Service: Was the service satisfactory?

4. Update Limits: Adjust if needed based on usage

Security Tips

Protect Your Wallet

• Never share private keys

• Use hardware wallet for large amounts

• Keep seed phrase offline

• Enable 2FA where possible

Verify Services

Before first use:

• Check service verification status

• Read reviews from other users

• Test with small payment first

• Verify service URL/address

Monitor Spending

• Review transaction history daily

• Set conservative limits initially

• Enable spending alerts

• Use separate wallet for testing

Recognize Scams

Red flags:

• Unverified services

• Unusually low prices

• Requests for private keys

• Off-chain payment requests

Advanced Features

Batch Payments

Coming soon:

"Pay for 10 API requests in advance"

Scheduled Payments

Coming soon:

"Set up recurring weekly payment"

Multi-Chain Routing

Coming soon:

• Auto-select cheapest chain

• Bridge tokens when needed

• Optimize for speed vs cost

Transaction History

View all payments:

Recent Transactions
────────────────────────────────────
Jan 31  WeatherAPI    0.001 SOL  ✓
Jan 31  Heurist Mesh  0.002 SOL  ✓
Jan 30  IPFS Pin      0.001 SOL  ✓
Jan 30  DataAPI       0.001 SOL  ❌
────────────────────────────────────

Filters:
[All] [Successful] [Failed] [Pending]

Export: [CSV] [JSON]

Troubleshooting

Payment Stuck

Solution:

1. Check block explorer

2. Verify transaction is pending

3. Wait 5-10 minutes

4. Contact support if persists

Wrong Amount Charged

Solution:

1. Check transaction on explorer

2. Verify service pricing

3. Account for gas fees

4. Contact service provider

Service Didn't Deliver

Solution:

1. Save transaction hash

2. Contact service support

3. Request refund if eligible

4. Report to Yuki402 support

Learn More

• Spending Limits

• Autonomous Payments

• Best Practices

• FAQ

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Need help? Email [email protected]