Payment

What is x402?

x402 is a blockchain-based payment protocol specifically designed for AI agents and autonomous systems. It enables:

1. Agent-to-Agent Payments: Direct economic interactions

2. Microtransactions: Cost-effective small payments

3. Automated Billing: Smart contract-based invoicing

4. Value Attribution: Track agent-generated value

5. Economic Autonomy: Agents manage their own finances

Payment Flow Details

Step 1: Wallet Connection

User → MetaMask Extension → Wallet Address
↓
Platform verifies wallet signature
↓
Session authenticated

Step 2: Network Verification

Check current network
↓
If not Base (8453) → Prompt network switch
↓
User approves in MetaMask
↓
Connection established

Step 3: Balance Check

Query USDC contract on Base
↓
Read user balance
↓
Verify ≥ $1.00 USDC available
↓
Display balance to user

Step 4: Transaction Construction

Contract: USDC Token (0x833589...)
Function: transfer
To: Grace Payment Processor
Amount: 1000000 (1 USDC in smallest units)
Gas Limit: Estimated automatically

Step 5: User Confirmation

MetaMask displays:
- Transaction details
- Gas fee estimate
- Total cost
User clicks "Confirm" or "Reject"

Step 6: Blockchain Processing

Transaction submitted to Base network
↓
Included in next block (~2 seconds)
↓
Confirmations: 1, 2, 3... (platform waits for 1)
↓
Transaction hash returned

Step 7: Server Verification

Platform receives tx hash
↓
Queries blockchain for transaction
↓
Verifies: amount, recipient, sender
↓
Validates payment signature
↓
Approval granted

Step 8: Agent Generation

Payment confirmed
↓
Agent configuration processed
↓
Code generated
↓
Saved to database
↓
Files prepared for download

Gas Fee Optimization

Typical Costs on Base:

• USDC Transfer: ~$0.01-0.02

• Network Congestion: Minimal impact

• Time of Day: No significant variance

Gas Saving Tips:

1. Keep small ETH balance for gas

2. Use recommended gas settings

3. Avoid transaction spam

4. Monitor Base network status

Transaction Security

Multi-Layer Verification:

1. Client-Side: JavaScript validation

2. Wallet: MetaMask approval

3. Blockchain: Smart contract execution

4. Server-Side: Backend verification

5. Database: Transaction logging

Security Features:

• No private key exposure

• Encrypted communication

• Rate limiting

• Fraud detection

• Transaction monitoring