❓FAQ
Got questions? We've got answers. No BS, just straight talk about autonomous payments and the x402 protocol.
🌟 General Questions
What is Yuki402?
Yuki402 is your autonomous AI payment agent that handles blockchain payments faster than you can say "gas fees." Built on the x402 protocol, she intercepts HTTP 402 Payment Required responses and executes crypto payments in milliseconds—no clicking, no manual approvals, just pure automation.
Think of it as: Autopay, but for the entire internet. Set your limits once, then Yuki handles everything while you focus on building.
Is Yuki402 free to use?
Hell yeah. 0% platform fees. We're not here to extract rent—we're here to enable the machine economy.
You only pay:
Service fees (set by each API provider)
Blockchain gas fees (~$0.01 on Solana, varies on other chains)
That's it. No subscriptions. No hidden costs. No "processing fees."
The alpha: Hold $YUKI tokens for lifetime fee-free access. Don't hold? Pay a tiny fee that goes straight into automatic buybacks. More payments = more buybacks = more value accruing to holders.
What makes Yuki402 different from traditional payment processors?
Traditional payment processors are slow, expensive, and require trusting middlemen. Yuki402 is the opposite:
Traditional Payments:
2-3 day settlement times
2-3% transaction fees
Requires accounts, KYC, OAuth
Chargebacks and fraud risk
Geographic restrictions
Platform takes 20-30% cut
Yuki402:
2-second settlement (on Solana)
Zero platform fees
No accounts or registration
Trustless blockchain verification
Works globally, borderless
Protocol is open source and free
Do I need cryptocurrency?
Yes—Yuki402 settles payments on-chain, so you'll need:
✅ A Web3 wallet (MetaMask, Phantom, Coinbase Wallet) ✅ Some crypto for service payments + gas fees ✅ Compatible chains (Solana, Ethereum, Polygon, Base)
New to crypto? Start on Solana devnet (free test tokens) before using real money. Get devnet SOL here.
What is the x402 protocol?
x402 is the open protocol that makes autonomous payments possible. Built around the HTTP 402 Payment Required status code (yes, it's been in the HTTP spec since 1997—we're just the first to use it properly).
How it works:
Your app requests data from an x402 API
API responds with HTTP 402 + payment instructions
Yuki intercepts, processes payment, and retries
API verifies payment proof on-chain, delivers data
Result: Instant, trustless, programmatic payments. No accounts, no middlemen, no friction.
Learn more:
x402.org - Protocol homepage
x402 Technical Docs - Implementation guide
GitHub - Open source code
🚀 Platform Questions
How do I access Yuki402?
Web app (easiest):
Visit yuki402.xyz
Click "Launch App"
Connect your wallet
Start making requests
Local development:
See Installation Guide for detailed local setup.
What browsers are supported?
Any modern browser with Web3 wallet support:
✅ Chrome (recommended) - Version 90+ ✅ Firefox - Version 88+ ✅ Brave - Built-in wallet, no extension needed ✅ Safari - Version 14+ (with MetaMask extension) ✅ Edge - Version 90+
Pro tip: Brave has the best native Web3 integration. No extension installation required.
Does it work on mobile?
Absolutely. Yuki402 is fully responsive and works on mobile wallets:
📱 iOS:
MetaMask Mobile browser
Phantom Mobile
Coinbase Wallet app
WalletConnect support
📱 Android:
MetaMask Mobile
Phantom Mobile
Trust Wallet
Coinbase Wallet
Caveat: Mobile UX varies by wallet provider. Desktop experience is currently smoother.
Do I need to create an account?
No. Yuki402 embraces crypto-native identity:
✅ Your wallet address is your identity ✅ No registration, email, or OAuth ✅ No personal data collected ✅ Privacy-first architecture ✅ Anonymous usage by default
Just connect and go. It's that simple.
💸 Using Yuki402
How do autonomous payments work?
Magic, basically. But here's the technical flow:
You ask: "Get me weather data for London"
Yuki reaches out to the WeatherAPI service
HTTP 402 received - Payment Required response with instructions
Yuki processes - Checks limits, verifies balance
Transaction signed - Wallet signs payment automatically
Broadcast to chain - Transaction submitted on-chain
2 seconds later - Payment confirmed
Retry with proof - Yuki retries request with payment receipt
Data delivered - API verifies proof, sends you the data
Total time: 3-5 seconds from request to data. Faster than manual approval.
What are spending limits?
Your safety net. Daily, weekly, and monthly caps on how much Yuki can spend autonomously.
Example setup:
How they work:
Limits are enforced by smart contracts on-chain
Yuki checks limits before every payment
If a payment would exceed your limit, it's blocked
Limits reset automatically (daily/weekly/monthly)
You can adjust anytime via wallet transaction
Golden rule: Start conservative, scale up gradually as you get comfortable.
How do I set spending limits?
Spending limits are configured through smart contracts:
During setup:
Deploy or configure the SpendingLimits contract
Set your daily/weekly/monthly caps in SOL or ETH
Approve Yuki to check these limits
Limits are now enforced automatically
To update limits:
Call the smart contract with new values
Sign the transaction with your wallet
New limits take effect immediately
See Configuration Guide for detailed instructions.
Can I cancel a payment after it's submitted?
No. Blockchain transactions are irreversible once submitted. This is fundamental to how blockchains work.
But you're protected:
Yuki checks limits BEFORE submitting
Shows cost estimates before processing
Spending limits prevent runaway costs
Failed transactions refund automatically (gas fee is still paid)
Pro tip: Set conservative limits so you're never in a position where you need to cancel.
What services can I access with Yuki402?
Any x402-compatible service. The ecosystem is growing daily.
Current services include:
📊 Data APIs
Weather data (OpenWeatherMap, WeatherAPI)
Financial markets (CoinGecko, crypto prices)
Sports scores and stats
News feeds and content
🤖 AI Services
Image generation (Stable Diffusion, DALL-E proxies)
Text analysis and NLP
Model inference APIs
AI model training
💾 Storage Services
IPFS pinning (Pinata, Web3.Storage)
Decentralized file storage
CDN and file hosting
⛓️ Web3 Services
Smart contract deployment (thirdweb)
Blockchain data APIs
DeFi protocol access
NFT minting services
Ask Yuki: "What services are available?" for real-time registry search.
Does Yuki402 save my chat history?
Nope. We're completely stateless for your privacy:
✅ Conversations are NOT stored on our servers ✅ Refresh the page = fresh start ✅ No conversation tracking or logging ✅ No analytics or telemetry
❌ You can't retrieve old conversations after refresh
What IS stored:
Transaction history (public on blockchain—nature of the beast)
Smart contract state (spending limits, on-chain)
Privacy first. We don't want your data. We don't need your data.
How much do services cost?
Costs vary wildly depending on the service:
Typical ranges:
Cheap ($0.01 - $0.10):
Weather API queries
Simple data lookups
Basic AI inference
Moderate ($0.10 - $1.00):
Image generation
Complex AI models
Premium data APIs
Expensive ($1.00+):
High-resolution image generation
Smart contract deployment
Large dataset access
Plus gas fees:
Solana: ~$0.01
Polygon: ~$0.05
Ethereum: $1-$20 (avoid unless necessary)
Pro tip: Ask Yuki for pricing before requesting. "How much does [service] cost?"
🔧 Technical Questions
What AI model powers Yuki402?
Google Gemini 2.0 Flash - the perfect balance of speed, cost, and intelligence.
Why Gemini 2.0 Flash:
⚡ Fastest response times (<1s)
💰 Most cost-effective
🧠 Smart enough for payment processing
🔍 Built-in web search capabilities
📊 Massive context window
Configuration:
Can I use a different model? Yes—customize in .env.local with OpenRouter. See Configuration Guide.
What blockchains are supported?
Yuki402 is chain-agnostic. We support any blockchain that speaks x402.
Currently supported:
⚡ Solana - Primary chain
2-second finality
$0.01 gas fees
Best for high-volume payments
⛓️ Ethereum - Main network
12-second finality
$1-$20 gas fees (varies)
Most service adoption
🟣 Polygon - Ethereum L2
2-3 second finality
$0.05 gas fees
Good balance of speed/cost
🔵 Base - Coinbase L2
2-second finality
$0.05 gas fees
Growing ecosystem
More chains coming: Arbitrum, Optimism, Avalanche, BSC
Where do payments go?
Directly to service providers. No middlemen, no escrow, no custody.
Flow:
Your wallet → Service provider wallet
Smart contract verifies payment
Service provider checks on-chain proof
Data delivered
100% peer-to-peer. Yuki facilitates, but never touches your funds.
Transparency: All transactions are publicly verifiable on block explorers.
How fast are payments?
Depends on the blockchain:
Solana
2 seconds
3-4 seconds
Polygon
2-3 seconds
4-5 seconds
Base
2 seconds
3-4 seconds
Ethereum
12-15 seconds
15-20 seconds
Total time includes:
Transaction submission
Blockchain confirmation
API verification
Data delivery
Bottom line: 3-5 seconds on fast chains. Way faster than any traditional payment processor (2-3 days).
Is my data private?
Privacy model:
✅ Conversations - Not stored anywhere ✅ Requests - Not tracked on our servers ✅ Wallet - Non-custodial, you control keys ✅ Personal data - We don't collect any
⚠️ Transactions - Public on blockchain (nature of blockchain) ⚠️ Service data - Privacy depends on service provider
We're privacy-first, but blockchain is inherently transparent. If you need true privacy, consider privacy-preserving chains or mixers (use responsibly).
Are transactions reversible?
No. Blockchain transactions are final and irreversible.
Why?
Fundamental property of blockchain consensus
Prevents double-spending attacks
Enables trustless transactions
What this means for you:
Double-check before confirming
Set conservative spending limits
Start with small amounts to test
No "undo" button exists
Disputes: Contact service provider directly. Future versions will include on-chain arbitration.
🛡️ Security Questions
Is Yuki402 secure?
Yes, with defense in depth:
🔐 Non-Custodial
You hold private keys
Yuki never touches your funds
Revoke access anytime
🔒 Spending Limits
Smart contract enforcement
On-chain caps
Automatic limit checks
🌐 HTTPS Encryption
All web traffic encrypted
Secure WebSocket connections
📜 Open Source
Smart contracts auditable
Community review
No black boxes
⚡ Rate Limiting
50-second cooldown between requests
Prevents spam and abuse
🔍 Service Verification
x402 registry checks
Prioritizes verified services
Bottom line: Secure by design. But crypto is risky—only use funds you can afford to lose.
Can Yuki402 steal my funds?
No. Architecturally impossible.
Why:
✅ Yuki never holds your private keys
✅ All transactions signed by YOUR wallet
✅ Smart contracts enforce spending limits
✅ You can revoke access instantly
✅ All transactions visible on-chain
What Yuki CAN do:
Request your wallet to sign transactions (within limits)
Process payments you've authorized
What Yuki CAN'T do:
Sign transactions without your wallet
Exceed your spending limits
Access funds after you disconnect
Hide transactions from you
Trust, but verify: Check our open-source contracts and code.
How do I protect myself?
Security best practices:
Set Conservative Limits
Start with 0.01 SOL/day (~$2.50)
Scale up gradually as you get comfortable
Never set limits you can't afford to lose
Use Dedicated Wallet
Create separate wallet for Yuki
Don't use your main holdings wallet
Keep only what you need for payments
Verify Services
Only use verified x402 services
Check service reputation
Start with small test requests
Monitor Spending
Check transaction history regularly
Use block explorers to verify
Set up wallet notifications
Keep Keys Safe
NEVER share your seed phrase
Use hardware wallet for large amounts
Enable wallet password/biometrics
Stay Updated
Follow @yuki402xyz for security updates
Update wallet extensions regularly
Review contract changes
What if a service doesn't deliver?
If you paid but didn't receive the service:
Save proof of payment
Transaction hash from block explorer
Screenshot of request/response
Timestamp of payment
Check transaction status
Verify payment confirmed on-chain
Check payment went to correct address
Ensure sufficient gas was paid
Contact service provider
Provide transaction hash as proof
Request refund or service delivery
Give them 24-48 hours to respond
Report to Yuki402
Email: [email protected]
Include all details and proof
We'll investigate and potentially delist bad actors
Future: On-chain disputes
Smart contract arbitration (coming soon)
Automated refund mechanisms
Reputation system for services
Pro tip: Test new services with small amounts first.
How do I report security issues?
Responsible disclosure process:
📧 Email: [email protected]
Please include:
Detailed description of vulnerability
Steps to reproduce
Potential impact assessment
Your contact info (optional, for bounty)
We'll respond within:
48 hours: Acknowledgment
7 days: Initial assessment
30 days: Fix deployed (critical issues)
Bug bounties available for critical vulnerabilities. Rewards based on severity.
DON'T:
Disclose publicly before we patch
Exploit for personal gain
Test on production/mainnet
We appreciate responsible researchers. You'll be credited (if you want) when we patch.
💳 Payment Questions
What happens if payment fails?
Failed transactions revert on-chain:
✅ Your funds are NOT deducted (except gas fee—that's paid either way) ✅ Yuki shows failure reason in chat ✅ You can retry with adjusted parameters
Common failure reasons:
🚫 Insufficient balance - Need more crypto 🚫 Gas too low - Network congestion, increase gas 🚫 Limit exceeded - Would exceed spending cap 🚫 Service unavailable - API is offline 🚫 Network congestion - Blockchain overloaded
What to do:
Read the error message (they're usually clear)
Fix the issue (add funds, wait, increase gas)
Retry the request
Contact support if stuck
Why did my transaction fail?
Top reasons for transaction failures:
1. Insufficient Balance
Not enough crypto for service + gas
Solution: Add funds to wallet, try again
2. Gas Too Low
Network congestion requires higher gas
Solution: Increase gas price/limit in wallet
3. Spending Limit Exceeded
Transaction would break daily/weekly/monthly cap
Solution: Wait for limit to reset or increase limit
4. Service Unavailable
x402 service is offline or rejecting requests
Solution: Try different service or wait
5. Network Congestion
Blockchain is overloaded, transactions timing out
Solution: Wait for congestion to clear, increase gas
6. Smart Contract Revert
Payment logic rejected transaction
Solution: Check error message, contact support
Pro tip: Check transaction on block explorer for detailed error messages.
How do I check transaction status?
Every payment includes a transaction hash (TxHash).
Use it to:
View on block explorer (Yuki provides clickable links)
Check confirmation status
See exact costs and gas used
Verify payment recipient
Get proof of payment for disputes
Block explorers:
Solana: solscan.io
Ethereum: etherscan.io
Polygon: polygonscan.com
Base: basescan.org
What to look for:
✅ "Success" status
✅ Confirmed block number
✅ Correct recipient address
✅ Expected amount
Can I get refunds?
Blockchain transactions are irreversible, but refunds are possible:
How refunds work:
Service provider issues NEW transaction
Refund goes back to your wallet
You receive crypto back (minus original gas)
When refunds happen:
Service failed to deliver
Service error/downtime
Duplicate payment
Service offers refund policy
Process:
Contact service provider with transaction hash
Request refund with reason
Wait for provider to process
Check wallet for refund transaction
Some services offer automatic refunds for failures. Check service terms.
Why are gas fees so high?
Gas fees fluctuate based on network demand:
Factors:
📈 Network Congestion
More users = higher fees
Peak times (US market hours) = expensive
⛓️ Chain Selection
Ethereum: $1-$20 (ouch)
Polygon: $0.05-$0.20
Solana: $0.01 (consistent)
🔥 Transaction Complexity
Simple transfers = cheap
Complex smart contract calls = expensive
🐂 Market Conditions
Bull markets = more activity = higher fees
Solutions:
✅ Use cheaper chains (Solana, Polygon) ✅ Transact during off-peak hours ✅ Wait for congestion to clear ✅ Use gas trackers to time transactions
Pro tip: Yuki automatically routes to the cheapest chain when possible.
🔧 Troubleshooting
My wallet won't connect
Try these solutions in order:
Check wallet is installed
Browser extension installed and enabled
Wallet app is updated to latest version
Unlock your wallet
Enter password/PIN
Wallet must be unlocked to connect
Refresh the page
Hard refresh (Ctrl+Shift+R / Cmd+Shift+R)
Clear browser cache if needed
Try different browser
Chrome works best for most wallets
Brave has native Web3 support
Check network
Wallet on supported network?
Switch to Ethereum Mainnet or Solana
Reinstall wallet extension
Last resort: uninstall and reinstall
Keep seed phrase safe before uninstalling!
Still stuck? Email [email protected] with browser/wallet details.
Payment is stuck pending
If your payment is taking forever:
Check block explorer
Use transaction hash to view status
Look for "Pending", "Success", or "Failed"
Wait 5-10 minutes
Network congestion can delay confirmation
Solana: Usually <2 minutes
Ethereum: Can be 15-30 minutes during congestion
Check for failure
If reverted/failed, you weren't charged (except gas)
Error message explains why
Contact support if >10 minutes
Email: [email protected]
Include transaction hash
We'll investigate
Transaction hash is your proof of payment - save it!
Insufficient balance error
This means you don't have enough crypto for the payment.
You need:
Service fee (e.g., 0.01 SOL)
Gas fee (e.g., 0.00001 SOL)
Small buffer (5-10% extra)
Solutions:
Add more crypto to wallet
Buy on exchange (Coinbase, Kraken, etc.)
Transfer from another wallet
Use on-ramp service (Moonpay, etc.)
Try cheaper service
Ask Yuki for alternatives
Some services have free tiers
Switch to cheaper chain
Solana gas is way cheaper than Ethereum
Request Yuki use specific chain
Service unavailable
If Yuki says a service is offline:
Reasons:
Service is temporarily down for maintenance
High traffic, service rate limiting
Service removed from x402 registry
Network issues between Yuki and service
What to do:
Wait a few minutes - Temporary outages are common
Try again - Service may be back online
Ask for alternatives - "What other weather APIs are available?"
Check x402 registry - x402.org/services
Report if persistent - Email support with service name
Some services have uptime SLAs - check service terms.
Wrong amount charged
If you were charged an unexpected amount:
Check block explorer
Verify actual amount sent
Look at transaction details
Account for gas fees
Gas is SEPARATE from service fee
Shows as two line items
Check service pricing
Services can have dynamic pricing
Prices may vary by request complexity
Verify with service provider
Contact them with transaction hash
Confirm their pricing structure
Report if genuinely wrong
Email: [email protected]
Include transaction hash and expected vs actual
We'll investigate and escalate to provider
🔮 Future Development
What features are coming?
Roadmap for 2026:
Q1 2026:
🔄 Multi-signature support for orgs
📅 Scheduled recurring payments
🔀 Batch processing (multiple payments in one tx)
🤝 Dispute resolution system
Q2 2026:
📱 Native iOS and Android apps
🔍 Enhanced service discovery marketplace
⚡ Auto-routing to cheapest chain
💎 $YUKI staking for premium features
Q3 2026:
🏢 Enterprise API for developers
🔌 JavaScript, Python, Go SDKs
📡 WebSocket support for real-time
🎨 White-label solutions
Q4 2026:
🔐 Privacy-preserving payments
🤖 AI-powered service recommendations
📊 Advanced analytics dashboard
🌐 Multi-language support
Want early access? Email [email protected]
Can I integrate Yuki402 into my app?
Developer API coming Q2 2026:
Features:
RESTful API for autonomous payments
WebSocket real-time updates
Full SDK support (JS, Python, Go)
White-label solutions
Custom branding options
Enterprise SLA support
Use cases:
Add autonomous payments to your dApp
Build AI agents that pay for services
Create payment-enabled chatbots
Integrate with existing tools
Interested? Join the waitlist: [email protected]
How can I add my service to x402?
Make your API x402-compatible in 4 steps:
1. Implement HTTP 402 flow
2. Verify payments
Check transaction on-chain
Verify amount and recipient
Confirm transaction is recent (<5 min)
3. Register in x402
Submit to x402 registry
Provide service details and pricing
Get verified status
4. Set pricing
Define per-request costs
Choose accepted chains
Document your API
Full guide: x402.gitbook.io/implementation
💬 Getting Help
Where can I get support?
Official channels:
📧 Email: [email protected]
Technical support
Bug reports
General questions
Response time: <24 hours
🐦 X/Twitter: @yuki402xyz
Updates and announcements
Quick questions
Community discussion
📖 Documentation: Right here!
Comprehensive guides
API reference
Troubleshooting
🐛 GitHub: github.com/yuki402-xyz/yuki402
Report bugs
Feature requests
Open source contributions
I have a feature request
We love hearing from users!
Submit via:
📧 Email: [email protected]
🐦 X: @yuki402xyz
🐛 GitHub: Open feature request issue
Include:
Clear description of feature
Use case and motivation
Expected behavior
Any mockups or examples
Popular requests get prioritized. Community feedback drives our roadmap.
How do I report a bug?
Bug reports should include:
Required:
Clear description of issue
Steps to reproduce
Expected vs actual behavior
Helpful:
Browser and version
Wallet and version
Transaction hash (if payment-related)
Screenshots or screen recording
Console errors (F12 → Console)
Send to: [email protected]
GitHub issues also welcome: github.com/yuki402-xyz/yuki402/issues
Where is the source code?
Yuki402 is fully open source:
🔗 GitHub: github.com/yuki402-xyz/yuki402
What's open source:
✅ Smart contracts (Solidity)
✅ Frontend (Next.js/React)
✅ API routes
✅ Payment processing logic
License: MIT - Free to use, modify, and deploy
Contributions welcome! Check CONTRIBUTING.md for guidelines.
💰 Cost & Economics
How much will I actually spend?
Realistic cost estimates:
Light User (few requests per week)
Service fees: ~$5-10/month
Gas fees: ~$2-5/month
Total: $7-15/month
Regular User (daily requests)
Service fees: ~$20-50/month
Gas fees: ~$5-15/month
Total: $25-65/month
Heavy User (multiple requests daily)
Service fees: $100-300/month
Gas fees: $10-30/month
Total: $110-330/month
Pro tip: Set spending limits to enforce budget.
Why use x402 instead of traditional payments?
Traditional payments suck. Here's why x402 is better:
Settlement Time
2-3 days
2 seconds
Platform Fees
2-3% + processing
0%
Registration
Required
Not required
Personal Data
Collected
Not collected
Geographic Limits
Yes
No (global)
Chargebacks
Yes (fraud risk)
No (trustless)
Merchant Accounts
Required
Not required
Currency Support
Fiat only
Any token
Bottom line: Faster, cheaper, more private, and globally accessible.
Are there any hidden fees?
No. Zero. Nada.
What you pay:
✅ Service fee (set by provider)
✅ Gas fee (paid to blockchain validators)
What you DON'T pay:
❌ Platform fees (Yuki402 charges 0%)
❌ Subscription fees
❌ Processing fees
❌ Currency conversion fees (for crypto)
❌ Withdrawal fees
❌ "Service charges"
100% transparent. Every transaction visible on-chain.
The $YUKI exception: Hold $YUKI tokens for lifetime fee-free access. Don't hold? Pay tiny fee (~1%) that funds automatic buybacks. Either way, no hidden costs.
Still have questions? Email [email protected] or tweet at @yuki402xyz. We're here to help.
Ready to try it? Head to yuki402.xyz and experience autonomous payments firsthand.
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