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Check out the x402 Article Marketplace (UI)

AI Validation

AI scores your content and generates optimized titles

No Gas Fees

Pay only the article price - zero transaction fees

100+ Sites

Submit to crypto news, DeFi, NFT sites

Instant Submission

One signature and your pitch is sent

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How It Works

1

Connect Wallet

Visit x402 Article Marketplace and connect your wallet on Base network
2

Choose Target Site

Select a crypto content site that matches your article topic
3

Provide Your Idea

Enter a tweet URL, topic idea, or complete article title
4

Review & Approve

See AI suggestions and approval score before paying
5

Submit & Pay

One signature with USDC - zero gas fees - instant submission to publisher

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AI Validation Rules

The AI validation endpoint scores your article idea and either approves it as-is, suggests improvements, or rejects it.
  • ✅ Score ≥90
  • ⚠️ Score 70-89
  • ❌ Score <70
Perfect! Your input is approved as-is.Your provided title or topic is excellent and fits the site’s focus. No changes needed - we’ll submit it exactly as you wrote it.Example: “How to Use Base Pay for Creators in Your DApp”

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Pricing

Article submission prices vary by site based on their traffic and authority. Typical Ranges:
  • Small/emerging sites: $10-50 USDC per submission
  • Mid-tier sites: $50-200 USDC per submission
  • Premium sites: $200-500 USDC per submission
Prices are set by individual publishers. Check the site details before submitting.

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API Reference

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Network & Payment Details

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Network
Base
Chain ID: 8453
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Payment Token
USDC
6 decimals
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Protocol
x402
ERC-20 Permit signatures
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Max Price
$1000
Maximum price per submission

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Validate Article Idea (Free)

POST https://x402.anyspend.com/articles/validate
Free endpoint to validate your article idea. AI generates a title, description, and approval score. Request Body: 
{
  "siteDomain": "baseradar.com",
  "userInput": "How to use Base Pay for creators"
}
Parameters:
  • siteDomain (required) - Target site domain (e.g., “baseradar.com”)
  • userInput (required) - Tweet URL, topic idea, or complete title (10-200 characters)
Input Options:
Provide a ready-to-use article title.
{
  "siteDomain": "baseradar.com",
  "userInput": "How to Build a DEX on Base with Uniswap V3"
}
If approved (score ≥90), your title is used as-is.
Provide a tweet URL with relevant content.
{
  "siteDomain": "solanaecho.com",
  "userInput": "https://x.com/BuildOnBase/status/1234567890"
}
AI extracts the topic and generates a title/description.
Provide a short topic or idea.
{
  "siteDomain": "baseradar.com",
  "userInput": "base pay for creators"
}
AI generates a complete title and description.

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Submit Article Request (x402 Payment)

POST https://x402.anyspend.com/articles/buy
Submit an article request with x402 payment. You must validate your content first and receive approval. Request Body: 
{
  "buyerAddress": "0x742d35Cc6...",
  "siteDomain": "baseradar.com",
  "title": "Integrating Base Pay: A Complete Guide for Content Creators",
  "description": "Learn how to implement Base Pay in your creator platform with step-by-step examples and best practices."
}
Parameters:
  • buyerAddress (required) - Your wallet address
  • siteDomain (required) - Target site domain
  • title (required) - Article title (from validation or your own if score ≥90)
  • description (required) - Article description (from validation or your own)
JavaScript/TypeScript Example: 
import { wrapFetchWithPayment } from '@b3dotfun/anyspend-x402-fetch';
import { createWalletClient, custom, publicActions } from 'viem';
import { base } from 'viem/chains';

// Step 1: Validate your content (FREE)
const validateResponse = await fetch('https://x402.anyspend.com/articles/validate', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    siteDomain: 'baseradar.com',
    userInput: 'How to use Base Pay for creators'
  })
});

const validation = await validateResponse.json();

if (!validation.data.approved) {
  console.error('Content rejected:', validation.data.reasoning);
  process.exit(1);
}

console.log('✅ Approved! Score:', validation.data.score);
console.log('Title:', validation.data.suggestedTitle);

// Step 2: Submit with payment (x402)
const walletClient = createWalletClient({
  account: '0x742d35Cc6...',
  chain: base,
  transport: custom(window.ethereum),
}).extend(publicActions);

const fetchWithPayment = wrapFetchWithPayment(
  fetch,
  walletClient,
  BigInt(1000 * 10 ** 6) // Max 1000 USDC
);

const response = await fetchWithPayment(
  'https://x402.anyspend.com/articles/buy',
  {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      buyerAddress: '0x742d35Cc6...',
      siteDomain: 'baseradar.com',
      title: validation.data.suggestedTitle,
      description: validation.data.suggestedDescription
    })
  }
);

const result = await response.json();
console.log('🎉 Article submitted! Request ID:', result.data.requestId);
See x402 SDK documentation for more details on using wrapFetchWithPayment.

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View Your Submissions (Free)

GET https://x402.anyspend.com/articles/requests/buyer/:address
Track all your article submissions - pending, accepted, and published. 
curl "https://x402.anyspend.com/articles/requests/buyer/0xYourAddress"
Status values:
  • pending - Submitted to publisher, awaiting review
  • accepted - Publisher accepted, article in production
  • published - Article is live (includes publishedUrl)
  • rejected - Publisher declined (rare, usually pre-validated)
Prices in API responses are in USDC wei (6 decimals). Divide by 1,000,000 to get USDC amount.

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Browse Sites (Free)

GET https://x402.anyspend.com/ads/sites
List all sites accepting article submissions. Same endpoint as ad marketplace - sites support both ads and articles. 
curl "https://x402.anyspend.com/ads/sites?limit=20"

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AI Validation Tips

Good: “How to Build a DEX on Base with Uniswap V3”Bad: “DeFi stuff”Specific titles score higher and are more likely to be approved.
Check site keywords and description before submitting. A Base-focused article won’t score well on a Solana-only site.
Good: “How to Use Base Pay for Creators in Your DApp”Bad: “base pay creators”Complete titles (10-200 chars) get higher scores.
If you have a viral tweet about your topic, use the URL! AI extracts context and generates a relevant title.

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Common Issues

Your topic doesn’t fit the site’s focus. Options:
  • Choose a different site that matches your topic better
  • Adjust your topic to align with the site’s keywords
  • Provide a more specific, detailed title
You must call /articles/validate first and get approval before calling /articles/buy.
You need USDC on Base network. Check that:
  • You’re connected to Base (Chain ID: 8453)
  • You have enough USDC for the article price
  1. Your request goes to the publisher for review
  2. Publisher evaluates your pitch (typically 1-7 days)
  3. If accepted, they’ll write/publish the article
  4. You’ll receive the published URL once live
Track status via /articles/requests/buyer/:address
No, submissions are locked after payment. Make sure your content is correct before submitting.
Publishers rarely reject pre-validated content, but if they do, the status will show “rejected”. Refunds are handled case-by-case - contact the publisher directly.

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Zero Gas with x402

x402 is the payment protocol that makes crypto payments feel like web2. Traditional crypto payments:
  • ❌ Multiple transactions (approve + transfer)
  • ❌ $5-15 in gas fees
  • ❌ 30-60 second wait times
  • ❌ Complex multi-step flows
With x402:
  • ✅ One signature - no transactions
  • ✅ Zero gas fees
  • ✅ Instant settlement
  • ✅ Simple one-click submission

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How It Works

  1. You sign a payment authorization message (not a transaction)
  2. x402 facilitator submits the transaction for you
  3. Facilitator pays the gas
  4. You pay only the article price
Always verify the amount and recipient before signing!

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Security

  • ✅ You control the signature
  • ✅ Signatures expire (can’t be replayed)
  • ✅ One-time use with unique nonce
  • ✅ Amount is locked (can’t charge more)
Related: Ad Marketplace • x402 Overview • x402scan →