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Frequently Asked Questions ​

General ​

What is 402x?

402x is a platform that enables instant, trustless micropayments across the internet. Built on the x402 Protocol, it allows creators, developers, researchers, and communities to monetize their work without subscriptions, accounts, or complex payment infrastructure.

How is 402x different from Stripe or PayPal?
Feature402xStripe/PayPal
Setup TimeMinutesDays/weeks
Payment SpeedInstant2-7 days
Fees1-2%2.9% + $0.30
MicropaymentsOptimized ($0.01+)Expensive (<$5)
Account RequiredNoYes
GlobalUnrestrictedGeographic limits
Is 402x only for cryptocurrency?

No. While 402x uses blockchain for settlement (primarily USDC stablecoin), we provide fiat on-ramps so users can pay with credit cards. The crypto is handled behind the scenes.

Do I need to understand blockchain to use 402x?

No. 402x abstracts away blockchain complexity. You can integrate payments with a few lines of code, just like any payment API.

Getting Started ​

How do I create an account?

Visit dashboard.402x.io and sign up with your email. You'll receive an API key and can start testing immediately in sandbox mode.

How long does integration take?
  • Widgets: 2 minutes (copy/paste embed code)
  • Paywalls: 5-10 minutes (add script tag)
  • APIs: 15-30 minutes (install SDK, add middleware)
  • Full integration: 1-2 hours
Do I need to write code?

Not necessarily. 402x Widgets are no-code solutions. For more advanced integrations (APIs, custom paywalls), basic coding knowledge is helpful.

Is there a test environment?

Yes! Use sandbox.402x.io to test without real money. You get test funds and full API access.

Payments ​

What currencies are supported?

Primary:

  • USDC (USD Coin stablecoin)
  • ETH (Ethereum)

Fiat On-Ramps:

  • USD (via credit card/bank)
  • EUR
  • GBP
  • More coming soon
What's the minimum payment amount?

As low as $0.01 (1 cent). Unlike traditional payment processors, micropayments are economically viable on 402x.

What's the maximum payment amount?

No hard limit, but transactions over $10,000 may trigger additional verification (KYC) for compliance.

How fast are payments?
  • Payment verification: <100ms
  • Content delivery: <200ms total
  • On-chain confirmation: ~2 seconds (Base L2)
  • Provider settlement: Instant
Can payments be refunded?

Yes. Providers can configure refund windows (typically 10 minutes to 24 hours). Refunds are processed instantly.

What happens if a payment fails?

Failed payments don't charge the user. The system automatically retries network errors or notifies the user if action is needed (e.g., insufficient funds).

Fees & Pricing ​

What are 402x fees?
  • Protocol fee: 1-2% of transaction amount
  • No monthly fees
  • No setup costs
  • No hidden charges

Example:

  • User pays $10
  • You receive $9.80-$9.90
  • 402x takes $0.10-$0.20
Are there any other costs?

Blockchain gas fees are minimal on Base L2 (~$0.001 per transaction) and are typically covered by 402x.

How do I get paid?

Payments arrive instantly in your configured wallet address. You can withdraw anytime or let funds accumulate.

Is there a minimum payout?

No minimum. Withdraw any amount, anytime.

How do taxes work?

402x provides transaction reports and tax documents (1099-K for US users). Consult your tax advisor for specific guidance.

Security ​

Is 402x secure?

Yes. Security measures include:

  • ✅ Multi-layered security architecture
  • ✅ Audited smart contracts
  • ✅ TLS 1.3 encryption
  • ✅ Multi-sig controls
  • ✅ Bug bounty program
  • ✅ 24/7 monitoring

See Security Model for details.

What if I lose my private key?

Private keys cannot be recovered. We recommend:

  • Using hardware wallets for large amounts
  • Backing up seed phrases securely
  • Testing recovery before storing significant funds
How is my data protected?
  • Minimal data collection (privacy-first)
  • AES-256 encryption at rest
  • TLS 1.3 encryption in transit
  • GDPR compliant
  • No PII stored unnecessarily
Can payments be reversed or chargebacked?

Blockchain payments are final and cannot be charged back like credit cards. However, providers can issue refunds within configured windows.

What about fraud protection?

402x includes:

  • Real-time fraud detection
  • Velocity checks
  • Pattern analysis
  • Device fingerprinting
  • Manual review for suspicious activity

Technical ​

What programming languages are supported?

Official SDKs:

  • JavaScript/TypeScript (Node.js, Browser)
  • Python
  • Go (coming soon)

REST API:

  • Works with any language that can make HTTP requests
Can I use 402x with my existing tech stack?

Yes! 402x integrates with:

  • WordPress
  • Next.js
  • Express.js
  • Django/Flask
  • Discord/Telegram
  • And more...

See our use case guides for integration examples.

Do you have webhooks?

Yes. 402x sends real-time webhook notifications for:

  • payment.confirmed
  • payment.pending
  • payment.failed
  • payment.refunded
  • payment.disputed
What's the API rate limit?

Production:

  • 100 requests/second per API key
  • 10,000 requests/hour
  • Custom limits available for enterprise

Sandbox:

  • More relaxed limits for testing
Can I test without real money?

Yes! Use the sandbox environment with test funds and test blockchain.

Use Cases ​

Can I use 402x for subscriptions?

Yes, but 402x shines for pay-per-use models. For recurring subscriptions, you can create payment schedules or use traditional subscription tools alongside 402x for one-time payments.

Can I offer free trials?

Yes. Configure products with:

  • Free preview periods
  • Grace periods before charging
  • Free tier + paid upgrades
Can I do pay-what-you-want pricing?

Yes. Set minimum price (including $0) and let users choose their amount.

Can AI agents use 402x?

Absolutely! 402x is designed for autonomous agents. AI can:

  • Post tasks with payment
  • Complete tasks for payment
  • Access paid APIs
  • Purchase research papers
  • All programmatically

Business ​

Is 402x legal?

Yes. 402x complies with:

  • FinCEN regulations (US)
  • Money transmitter laws
  • AML/KYC requirements
  • International financial regulations
Do I need a business license?

Depends on your jurisdiction and volume. Consult local regulations. 402x provides compliance tools but you're responsible for your business compliance.

Can I use 402x internationally?

Yes! 402x works globally. No geographic restrictions for most use cases.

What about sales tax/VAT?

You're responsible for collecting and remitting applicable taxes. 402x provides transaction reports to help with tax compliance.

Is there enterprise support?

Yes. Enterprise features include:

  • Dedicated support
  • Custom rate limits
  • SLA guarantees
  • White-label options
  • Volume discounts

Contact [email protected]

Troubleshooting ​

Payment not confirming

Check:

  1. Wallet has sufficient funds
  2. Network connectivity
  3. Correct network (Base mainnet vs testnet)
  4. Transaction hash in block explorer

Solution:

javascript
// Check payment status
const payment = await x402.payments.get(paymentId);
console.log('Status:', payment.status);
console.log('Error:', payment.error);
Webhook not received

Check:

  1. Webhook URL is publicly accessible
  2. HTTPS (not HTTP)
  3. Accepts POST requests
  4. Returns 200 status code
  5. Responds quickly (<5 seconds)

Test:

bash
curl -X POST https://your-domain.com/webhooks/402x \
  -H "Content-Type: application/json" \
  -d '{"test": true}'
API returning 401 Unauthorized

Check:

  1. API key is correct
  2. Using right environment (sandbox vs production)
  3. Key hasn't been revoked
  4. Authorization header format: Bearer sk_live_...
Content not unlocking after payment

Check:

  1. Payment confirmed (not just pending)
  2. Amount matches expected price
  3. Webhook received and processed
  4. Content delivery logic triggered

Account & Billing ​

How do I upgrade my plan?

Visit dashboard.402x.io/billing to view plans and upgrade.

Can I cancel anytime?

Yes. No lock-in contracts. Cancel anytime from dashboard.

What happens to my data if I cancel?
  • Payment history: Retained for 7 years (compliance)
  • Personal data: Deleted within 30 days per GDPR
  • API access: Terminated immediately
  • Funds: Withdraw before canceling
Can I get a refund?

Depends on situation. Contact [email protected] with your case.

Support ​

How do I get help?

Self-Service:

Direct Support:

What are support response times?
PriorityResponse Time
Critical<1 hour
High<4 hours
Medium<24 hours
Low<48 hours
Do you offer implementation support?

Yes, especially for enterprise customers. We can:

  • Review your architecture
  • Provide implementation guidance
  • Help with testing
  • Assist with launch
Where can I report bugs?

Roadmap & Future ​

What's coming next?

2025 Q4:

  • Multi-chain support (Optimism, Arbitrum)
  • Advanced analytics dashboard
  • Mobile SDK

2026 Q1:

  • Payment channels for ultra-low fees
  • Subscription management
  • Improved fraud detection

Visit 402x.io for the latest roadmap updates.

Can I request features?

Yes! We love feedback:

Will 402x support other blockchains?

Yes. Multi-chain support is planned for Q4 2025, starting with Optimism and Arbitrum.

Comparison Questions ​

402x vs Stripe
  • 402x: Instant settlement, crypto-native, lower fees, no accounts needed
  • Stripe: Established, fiat-only, higher fees, requires accounts
402x vs Patreon
  • 402x: Pay-per-use, no subscriptions, instant payouts, lower fees
  • Patreon: Subscription-focused, monthly payouts, higher fees
402x vs Traditional Ads
  • 402x: Direct monetization, privacy-friendly, no ad clutter
  • Ads: Intrusive, privacy concerns, low CPM, hurts UX
402x vs Micropayment services (Flattr, etc.)
  • 402x: Instant settlement, blockchain-based, global, developer-friendly
  • Others: Often discontinued or limited reach

Still Have Questions? ​

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