x402 Protocol

x402 is ALIAS's primary payment method, offering one-click payments directly from your browser wallet. It's designed for desktop users who want the fastest possible checkout experience.

What is x402?

x402 is a payment protocol built on Solana that enables direct, browser-based cryptocurrency transactions without QR codes or external devices.

Simple explanation: Think of x402 like clicking "Pay with PayPal" on a website—your wallet opens, you approve, and the payment is complete. No copying addresses, no QR codes, no switching devices.

Technical explanation (still simple): x402 creates a payment request in your browser. Your Solana wallet extension detects it and pops up asking for approval. Once you approve, the transaction is signed and submitted to Solana. The website verifies the transaction and completes your purchase.

How x402 Works (Step-by-Step)

Understanding the flow helps you know what to expect when using x402.

Step 1: Select amount and payment method You choose how much you want to load on your card and select "x402 Protocol" as your payment method.

Step 2: Click "Create Card" ALIAS generates a payment request with the amount, recipient address, and transaction details.

Step 3: Wallet popup appears Your browser wallet extension (Phantom, Solflare, Backpack, etc.) automatically detects the payment request and opens.

Step 4: Review transaction The wallet shows you exactly what you're paying: amount, token, and recipient. Verify these details match what you selected.

Step 5: Approve payment Click "Approve" or "Confirm" in your wallet. Your wallet signs the transaction and sends it to the Solana blockchain.

Step 6: Blockchain confirmation Solana confirms your transaction (typically under 1 second). ALIAS watches the blockchain for your payment.

Step 7: Card creation Once confirmed, ALIAS creates your virtual card and displays the details in your dashboard.

Total time: Under 2 seconds from approval to card delivery.

Benefits of x402

Speed: Fastest payment method available. Desktop users complete checkout in under 2 seconds.

Simplicity: One popup, one click, one confirmation. Minimal steps between decision and card.

Security: Your wallet never shares private keys. You approve every transaction explicitly.

No Device Switching: Everything happens in your browser. No need to grab your phone to scan QR codes.

Desktop Optimized: Designed for users browsing on desktop computers with wallet extensions installed.

Wide Wallet Support: Works with Phantom, Solflare, Backpack, Ledger, and all major Solana wallet extensions.

Best For Desktop Users

x402 shines when you're using a desktop or laptop computer.

Ideal setup:

• Desktop or laptop computer
• Browser wallet extension installed (Phantom, Solflare, etc.)
• Browsing and paying from the same device
• Fast internet connection

Why desktop is better for x402: Browser extensions only work on desktop browsers (not mobile). Mobile users should use Solana Pay instead.

Larger screens make it easier to review transaction details in the wallet popup.

Desktop users typically have fewer interruptions during checkout.

Can you use x402 on mobile? Not really. Mobile browsers don't support wallet extensions like desktop browsers do. Mobile users should use Solana Pay with QR codes.

Supported Wallets

x402 works with any Solana wallet that supports browser extensions.

Most popular wallets:

• Phantom: Most widely used Solana wallet, excellent x402 support
• Solflare: Powerful wallet with advanced features
• Backpack: Modern wallet with clean interface
• Glow: Privacy-focused wallet option
• Ledger: Hardware wallet with browser extension support

How to set up:

1. Install your preferred wallet extension from their official website
2. Create a new wallet or import existing one
3. Fund it with SOL (for gas fees) and USDC/other tokens (for cards)
4. Visit ALIAS and connect your wallet

All wallets work the same: The x402 experience is identical regardless of which wallet you use. Choose based on your personal preferences for security, features, and interface design.

Transaction Verification

x402 transactions are verified on the Solana blockchain before cards are created.

What gets verified:

Transaction exists: Payment was actually submitted to Solana blockchain

Transaction confirmed: Not just pending—must have blockchain confirmation

Correct amount: You sent exactly what the card costs

Correct recipient: Payment went to ALIAS treasury address

Correct token: Paid in the token you selected (USDC, SOL, etc.)

Not reused: Transaction signature hasn't been used for another card

Why blockchain verification matters: Prevents fraud and ensures you actually paid before receiving card details. Everything is transparent and verifiable on-chain.

How long verification takes: Solana confirmation is typically 400-800 milliseconds (under 1 second). ALIAS verification adds another 200-500 milliseconds.

Common Issues & Solutions

Wallet popup doesn't appear

Possible causes:

• Wallet extension not installed
• Wallet extension locked or disconnected
• Browser blocking popups
• JavaScript disabled

Solutions:

• Install a Solana wallet extension from official website
• Unlock your wallet by clicking the extension icon
• Allow popups for ALIAS website in browser settings
• Enable JavaScript in browser settings

Transaction fails after approval

Possible causes:

• Not enough SOL for gas fees
• Network congestion (rare on Solana)
• Wallet timed out during signing
• Transaction was rejected by wallet internally

Solutions:

• Ensure you have at least 0.01 SOL for transaction fees
• Try again—usually works on second attempt
• Check wallet logs for specific error messages
• Reconnect wallet and retry

Card not created after payment

Possible causes:

• Payment confirmed but card creation failed
• Network delay between payment and card provider API
• Transaction verification error

Solutions:

• Wait 10 seconds and refresh the page
• Check your dashboard for the new card
• Verify transaction on Solana explorer (solscan.io or explorer.solana.com)
• Contact support with transaction signature if card doesn't appear after 1 minute

Wrong amount charged

Possible causes:

• Price display error (rare)
• Selected wrong amount before approving
• Token price conversion shown incorrectly

Solutions:

• Always review the amount in your wallet popup before approving
• Contact support immediately with transaction signature
• Check your wallet history to see exact amount sent

Troubleshooting Tips

Before starting:

• Install and unlock your wallet extension
• Fund with SOL for gas (at least 0.01 SOL)
• Fund with payment token (USDC, SOL, etc.)
• Disable ad blockers that might interfere
• Use updated browser and wallet versions

During checkout:

• Review transaction carefully in wallet popup
• Don't close wallet popup while transaction is processing
• Wait for full confirmation before closing browser
• Save card details immediately after creation

If something goes wrong:

• Check wallet transaction history
• Look up transaction on Solana blockchain explorer
• Refresh ALIAS dashboard to check for card
• Contact support with specific error messages and transaction signatures

Security Best Practices

x402 is secure, but you should still follow best practices.

Wallet security:

• Never share your seed phrase or private keys
• Always verify recipient address in wallet popup
• Use hardware wallets (Ledger) for large amounts
• Keep wallet extension updated

Transaction security:

• Only approve transactions you initiated
• Verify amount and token before approving
• Don't approve transactions if recipient address looks suspicious
• Close wallet after each session

General security:

• Use strong passwords for wallet
• Enable two-factor authentication if available
• Don't install unknown wallet extensions
• Download wallets only from official websites

Comparison with Solana Pay

Both payment methods work well—choose based on your situation.

Use x402 when:

• You're on desktop with wallet extension
• You want the fastest checkout
• You prefer one-click payments
• You don't want to use QR codes

Use Solana Pay when:

• You're browsing on desktop but wallet is on mobile
• You prefer mobile wallets
• You want to pay from a different device
• Your wallet doesn't have browser extension support

Next Steps

Learn more about ALIAS payment options:

• Solana Pay - QR code payment method
• Payment Methods Overview - Compare both options
• Creating Cards - Step-by-step card creation guide
• Quick Start - Get your first card in 5 minutes