> ## Documentation Index
> Fetch the complete documentation index at: https://docs.b3.fun/llms.txt
> Use this file to discover all available pages before exploring further.

# x402 Crypto Ads

> Advertise on crypto sites with zero gas fees using x402

[Check out the x402 Ad Marketplace (UI)](https://explorer.b3.fun/apps/x402-ad-marketplace)

Buy advertising space on 100+ crypto content sites using USDC with **zero gas fees** thanks to x402 gasless payments.

<CardGroup cols={2}>
  <Card title="No Gas Fees" icon="gas-pump">
    Pay only the ad price - zero transaction fees
  </Card>

  <Card title="Instant Booking" icon="bolt">
    One signature and you're live
  </Card>

  <Card title="100+ Sites" icon="globe">
    Choose from crypto news, DeFi, NFT sites
  </Card>

  <Card title="AI-Powered Content" icon="brain">
    Submit articles with AI validation and generation
  </Card>

  <Card title="Real Analytics" icon="chart-line">
    See traffic data before you buy
  </Card>

  <Card title="Track Everything" icon="list-check">
    Monitor your ads and article requests in real-time
  </Card>
</CardGroup>

## Quick Start

<Tabs>
  <Tab title="Display Ads">
    <Steps>
      <Step title="Connect Wallet">
        Visit [x402 Ad Marketplace](https://explorer.b3.fun/apps/x402-ad-marketplace) and connect your wallet on Base network
      </Step>

      <Step title="Browse Sites">
        Explore sites with traffic stats, pick your target audience
      </Step>

      <Step title="Choose Format & Time">
        Select ad format (Banner/Sidebar/Leaderboard) and time slot
      </Step>

      <Step title="Upload Ad">
        Provide image URL and landing page
      </Step>

      <Step title="Sign & Pay">
        One signature with USDC - zero gas fees - instant confirmation
      </Step>
    </Steps>
  </Tab>

  <Tab title="Article Submissions">
    <Steps>
      <Step title="Connect Wallet">
        Visit [x402 Ad Marketplace](https://explorer.b3.fun/apps/x402-ad-marketplace) and connect your wallet on Base network
      </Step>

      <Step title="Select Target Site">
        Choose from crypto news sites that accept article submissions
      </Step>

      <Step title="Submit Your Idea">
        Provide a tweet URL, topic, or complete article title
      </Step>

      <Step title="AI Validation">
        Get instant AI feedback with score (0-100) and suggestions
      </Step>

      <Step title="Review & Submit">
        If approved (score ≥70), submit with one x402 signature
      </Step>

      <Step title="Track Progress">
        Monitor status and get notified when published
      </Step>
    </Steps>
  </Tab>
</Tabs>

<Note>
  Need USDC on Base? Bridge from Ethereum using [Base Bridge](https://bridge.base.org)
</Note>

## Ad Formats & Pricing

<Tabs>
  <Tab title="Wide banner">
    **970×250 pixels** - Wide banner format

    **Price:** 1 USDC/hour

    Best for cost-effective campaigns with good visibility
  </Tab>

  <Tab title="Sidebar">
    **300×600 pixels** - Vertical side placement

    **Price:** 2 USDC/hour

    Best for persistent visibility as users scroll
  </Tab>

  <Tab title="Leaderboard">
    **728×90 pixels** - Top banner position

    **Price:** 3 USDC/hour

    Best for maximum visibility and brand awareness
  </Tab>
</Tabs>

**Duration:** 1 hour minimum, 7 days (168 hours) maximum

## Article Submissions

Submit article ideas to crypto content sites. AI validates your topic and generates optimized titles and descriptions.

### How It Works

<Steps>
  <Step title="Submit Topic or Tweet">
    Provide a tweet URL, topic idea, or complete article title
  </Step>

  <Step title="AI Validation (Free)">
    AI scores your content (0-100) and generates suggestions if needed
  </Step>

  <Step title="Get Approval">
    * **Score ≥80:** Your input is perfect, accepted as-is
    * **Score 70-79:** Approved with AI-improved suggestions
    * **Score \<70:** Rejected - try a different topic
  </Step>

  <Step title="Submit & Pay">
    One x402 signature to submit your article request
  </Step>

  <Step title="Publication">
    Site publishes your article and you receive the live URL
  </Step>
</Steps>

### Pricing

Prices vary by site, typically **\$3-50 USDC** per article. Each site sets their own rate based on traffic and audience.

<Note>
  Validation is free! You can validate as many ideas as you want before committing to payment.
</Note>

## API Reference

### Network & Payment Details

<ParamField path="Network" type="Base">
  Chain ID: 8453
</ParamField>

<ParamField path="Payment Token" type="USDC">
  6 decimals
</ParamField>

<ParamField path="Protocol" type="x402">
  ERC-20 Permit signatures
</ParamField>

<ParamField path="Max Price" type="$1000">
  Maximum price per booking
</ParamField>

### Purchase Ad Slot (x402 Payment)

```bash theme={null}
POST https://x402.anyspend.com/ads/buy
```

Programmatically purchase ad slots using x402 gasless payments. This endpoint requires x402 payment authorization.

**Request Body:**

<CodeGroup>
  ```json Request theme={null}
  {
    "productId": "slot_abc123",
    "buyerAddress": "0x742d35Cc6...",
    "startTime": "2025-01-15T14:00:00Z",
    "endTime": "2025-01-15T18:00:00Z",
    "adContent": {
      "imageUrl": "https://...",
      "linkUrl": "https://...",
      "altText": "Alt text",
      "title": "Ad title",
      "description": "Description"
    }
  }
  ```

  ```json Success Response (200) theme={null}
  {
    "success": true,
    "data": {
      "purchaseId": "purch_123...",
      "bookingId": "booking_456...",
      "totalPrice": "5000000",
      "status": "confirmed"
    }
  }
  ```

  ```json Error Response (400) theme={null}
  {
    "success": false,
    "error": "Slot already booked during this time"
  }
  ```
</CodeGroup>

**Parameters:**

* `productId` (required) - The ad slot ID from `/ads/slots`
* `buyerAddress` (required) - Your wallet address
* `startTime` (required) - Start time in ISO 8601 format
* `endTime` (required) - End time in ISO 8601 format
* `adContent.imageUrl` (required) - Direct URL to ad image
* `adContent.linkUrl` (required) - Landing page URL
* `adContent.altText` (required) - Image alt text
* `adContent.title` (optional) - Ad title
* `adContent.description` (optional) - Ad description

**JavaScript/TypeScript Example:**

```typescript theme={null}
import { wrapFetchWithPayment } from '@b3dotfun/anyspend-x402-fetch';
import { createWalletClient, custom, publicActions } from 'viem';
import { base } from 'viem/chains';

// Create wallet client
const walletClient = createWalletClient({
  account: '0x742d35Cc6...',
  chain: base,
  transport: custom(window.ethereum),
}).extend(publicActions);

// Wrap fetch with x402 payment
const fetchWithPayment = wrapFetchWithPayment(
  fetch,
  walletClient,
  BigInt(1000 * 10 ** 6) // Max 1000 USDC
);

// Purchase ad slot
const response = await fetchWithPayment(
  'https://x402.anyspend.com/ads/buy',
  {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      productId: 'slot_abc123',
      buyerAddress: '0x742d35Cc6...',
      startTime: '2025-01-15T14:00:00Z',
      endTime: '2025-01-15T18:00:00Z',
      adContent: {
        imageUrl: 'https://example.com/ad.jpg',
        linkUrl: 'https://example.com',
        altText: 'My ad',
        title: 'Check out our product!',
        description: 'Limited offer'
      }
    })
  }
);

const result = await response.json();
console.log('Booking ID:', result.data.bookingId);
```

<Note>
  See [x402 SDK documentation](/anyspend/x402-overview) for more details on using `wrapFetchWithPayment`.
</Note>

### Browse Sites (Free)

```bash theme={null}
GET https://x402.anyspend.com/ads/sites
```

List all available sites with pagination. This endpoint is free to call.

Query parameters:

* `page` - Page number (default: 1)
* `limit` - Results per page (default: 20, max: 100)
* `search` - Search by name/domain/keywords

<CodeGroup>
  ```bash cURL theme={null}
  curl "https://x402.anyspend.com/ads/sites?search=defi&limit=10"
  ```

  ```javascript JavaScript theme={null}
  const sites = await fetch('https://x402.anyspend.com/ads/sites?page=1&limit=20')
    .then(r => r.json());
  ```

  ```json Response theme={null}
  {
    "success": true,
    "data": [
      {
        "siteId": "abc123",
        "siteName": "Crypto News Daily",
        "siteUrl": "https://cryptonews.example.com",
        "siteDomain": "cryptonews.com",
        "description": "Daily crypto news and analysis",
        "keywords": ["crypto", "bitcoin", "defi"],
        "availableSlots": ["leaderboard", "sidebar", "banner"],
      }
    ],
    "pagination": {
      "page": 1,
      "limit": 20,
      "total": 156,
      "hasNext": true
    }
  }
  ```
</CodeGroup>

### List All Slots (Free)

```bash theme={null}
GET https://x402.anyspend.com/ads/slots
```

List all available ad slots across all sites. This endpoint is free to call.

<CodeGroup>
  ```bash cURL theme={null}
  curl "https://x402.anyspend.com/ads/slots"
  ```

  ```javascript JavaScript theme={null}
  const slots = await fetch('https://x402.anyspend.com/ads/slots')
    .then(r => r.json());
  ```

  ```json Response theme={null}
  {
    "success": true,
    "data": [
      {
        "slotId": "slot_abc123",
        "siteId": "site_123",
        "slotType": "leaderboard",
        "pricePerHour": "5000000"
      }
    ]
  }
  ```
</CodeGroup>

### Get Slot Details (Free)

```bash theme={null}
GET https://x402.anyspend.com/ads/slots/:slotId
```

Returns static slot information including pricing, format, and associated site details. This endpoint is free to call.

<CodeGroup>
  ```bash cURL theme={null}
  curl "https://x402.anyspend.com/ads/slots/slot_banner_abc123"
  ```

  ```json Response theme={null}
  {
    "success": true,
    "data": {
      "slot": {
        "slotId": "slot_banner_abc123",
        "siteId": "abc123",
        "slotType": "banner",
        "pricePerHour": "1000000",
        "available": true
      },
      "site": {
        "siteName": "Crypto News Daily",
        "siteUrl": "https://cryptonews.example.com"
      }
    }
  }
  ```
</CodeGroup>

### Check Current Ad (Free)

```bash theme={null}
GET https://x402.anyspend.com/ads/slots/:slotId/current-ad
```

Returns the ad currently running in this slot, or indicates if the slot is available. This endpoint is free to call.

<CodeGroup>
  ```bash cURL theme={null}
  curl "https://x402.anyspend.com/ads/slots/slot_banner_abc123/current-ad"
  ```

  ```json Ad Running theme={null}
  {
    "success": true,
    "data": {
      "type": "paid",
      "ad": {
        "imageUrl": "https://example.com/ad.png",
        "linkUrl": "https://example.com/landing"
      },
      "booking": {
        "bookingId": "booking_xyz789",
        "startTime": "2024-02-01T10:00:00.000Z",
        "endTime": "2024-02-01T13:00:00.000Z"
      }
    }
  }
  ```

  ```json Slot Available theme={null}
  {
    "success": true,
    "data": {
      "type": "empty"
    }
  }
  ```
</CodeGroup>

### View Your Campaigns (Free)

```bash theme={null}
GET https://x402.anyspend.com/ads/bookings/buyer/:address
```

Track all your ad bookings - active, pending, and completed. This endpoint is free to call.

<CodeGroup>
  ```bash cURL theme={null}
  curl "https://x402.anyspend.com/ads/bookings/buyer/0xYourAddress"
  ```

  ```json Response theme={null}
  {
    "success": true,
    "data": [
      {
        "bookingId": "booking_xyz789",
        "siteId": "abc123",
        "slotType": "banner",
        "startTime": "2024-02-01T10:00:00.000Z",
        "endTime": "2024-02-01T13:00:00.000Z",
        "adContent": {
          "imageUrl": "https://mysite.com/ad.png",
          "linkUrl": "https://mysite.com/landing"
        },
        "totalPrice": "3000000",
        "status": "active",
        "paymentTxHash": "0xabcdef...",
        "createdAt": "2024-01-22T16:30:00.000Z"
      }
    ]
  }
  ```
</CodeGroup>

**Status values:**

* `active` - Currently running
* `pending` - Scheduled for future
* `completed` - Campaign ended

<Info>
  Prices in API responses are in USDC wei (6 decimals). Divide by 1,000,000 to get USDC amount.
</Info>

***

## Article Submission Endpoints

### Validate Article Idea (Free)

```bash theme={null}
POST https://x402.anyspend.com/articles/validate
```

Validate an article idea and get AI-generated title and description. This endpoint is free to call - no payment required.

**Request Body:**

<CodeGroup>
  ```json Request theme={null}
  {
    "siteDomain": "baseradar.com",
    "userInput": "How to Use Base Pay for Creators in Your DApp"
  }
  ```

  ```json Approved Response (Score ≥70) theme={null}
  {
    "success": true,
    "data": {
      "approved": true,
      "score": 92,
      "reasoning": "Excellent topic match for Base ecosystem content",
      "estimatedPrice": "15000000",
      "suggestedTitle": "How to Use Base Pay for Creators in Your DApp",
      "suggestedDescription": "Learn how to integrate Base Pay...",
      "userProvidedTitle": true,
      "message": "Your input is approved as-is"
    }
  }
  ```

  ```json Rejected Response (Score <70) theme={null}
  {
    "success": false,
    "data": {
      "approved": false,
      "score": 45,
      "reasoning": "Topic doesn't align with site's focus on Base ecosystem",
      "estimatedPrice": "15000000",
      "message": "Content doesn't fit the site's focus"
    }
  }
  ```
</CodeGroup>

**Parameters:**

* `siteDomain` (required) - Target site domain (e.g., "baseradar.com", "solanaecho.com")
* `userInput` (required) - Can be:
  * Complete article title (10-200 characters)
  * Tweet URL (e.g., "[https://x.com/username/status/](https://x.com/username/status/)...")
  * Topic or idea (e.g., "base pay for creators")

**AI Scoring:**

* **Score ≥80:** Your input is perfect! Used as-is
* **Score 70-79:** Good content, AI provides improved suggestions
* **Score \<70:** Rejected - topic doesn't fit the site

**JavaScript Example:**

```javascript theme={null}
const response = await fetch('https://x402.anyspend.com/articles/validate', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    siteDomain: 'baseradar.com',
    userInput: 'How to bridge assets to Base chain'
  })
});

const result = await response.json();
console.log('Approved:', result.data.approved);
console.log('Score:', result.data.score);
console.log('Title:', result.data.suggestedTitle);
```

### Submit Article Request (x402 Payment)

```bash theme={null}
POST https://x402.anyspend.com/articles/buy
```

Submit an article request with x402 gasless payment. Requires prior validation approval.

**Request Body:**

<CodeGroup>
  ```json Request theme={null}
  {
    "buyerAddress": "0x742d35Cc6...",
    "siteDomain": "baseradar.com",
    "title": "How to Use Base Pay for Creators in Your DApp",
    "description": "Learn how to integrate Base Pay into your decentralized application..."
  }
  ```

  ```json Success Response (200) theme={null}
  {
    "success": true,
    "data": {
      "requestId": "req_abc123...",
      "productSpecificId": "req_abc123...",
      "totalPrice": "15000000",
      "status": "pending"
    }
  }
  ```

  ```json Error Response (400) theme={null}
  {
    "success": false,
    "error": "Title is required and must be 10-200 characters"
  }
  ```
</CodeGroup>

**Parameters:**

* `buyerAddress` (required) - Your wallet address
* `siteDomain` (required) - Target site domain
* `title` (required) - Article title (10-200 characters)
* `description` (required) - Article description/summary

**JavaScript/TypeScript Example:**

```typescript theme={null}
import { wrapFetchWithPayment } from '@b3dotfun/anyspend-x402-fetch';
import { createWalletClient, custom, publicActions } from 'viem';
import { base } from 'viem/chains';

// Create wallet client
const walletClient = createWalletClient({
  account: '0x742d35Cc6...',
  chain: base,
  transport: custom(window.ethereum),
}).extend(publicActions);

// Wrap fetch with x402 payment
const fetchWithPayment = wrapFetchWithPayment(
  fetch,
  walletClient,
  BigInt(1000 * 10 ** 6) // Max 1000 USDC
);

// Submit article request
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: 'How to Use Base Pay for Creators in Your DApp',
      description: 'Learn how to integrate Base Pay into your decentralized application for seamless creator payments.'
    })
  }
);

const result = await response.json();
console.log('Request ID:', result.data.requestId);
```

### View Your Article Requests (Free)

```bash theme={null}
GET https://x402.anyspend.com/articles/requests/buyer/:address
```

Track all your article requests - pending, in progress, and published. This endpoint is free to call.

<CodeGroup>
  ```bash cURL theme={null}
  curl "https://x402.anyspend.com/articles/requests/buyer/0xYourAddress"
  ```

  ```json Response theme={null}
  {
    "success": true,
    "data": [
      {
        "requestId": "req_abc123",
        "siteName": "Base Radar",
        "siteDomain": "baseradar.com",
        "title": "How to Use Base Pay for Creators",
        "description": "Learn how to integrate Base Pay...",
        "totalPrice": "15000000",
        "status": "published",
        "publishedUrl": "https://baseradar.com/articles/base-pay-creators",
        "createdAt": "2025-01-15T10:00:00.000Z",
        "updatedAt": "2025-01-16T15:30:00.000Z"
      }
    ]
  }
  ```
</CodeGroup>

**Status values:**

* `pending` - Waiting for site to write article
* `in_progress` - Article is being written
* `published` - Article is live (includes `publishedUrl`)
* `rejected` - Article request was declined

***

## 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 purchase

### 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 ad price

<Warning>
  Always verify the amount and recipient before signing!
</Warning>

### Security

* ✅ You control the signature
* ✅ Signatures expire (can't be replayed)
* ✅ One-time use with unique nonce
* ✅ Amount is locked (can't charge more)

## Tips for Success

<AccordionGroup>
  <Accordion title="Design Eye-Catching Ads">
    * Use high contrast colors
    * Keep text large and readable
    * Include a clear call-to-action
    * Test image URL before booking
  </Accordion>

  <Accordion title="Target the Right Audience">
    * Match sites to your target market
    * Check traffic stats before booking
    * Consider multiple smaller sites vs one large site
  </Accordion>

  <Accordion title="Track Performance">
    Use UTM parameters in your landing page URL:

    ```
    https://yoursite.com?utm_source=sitename&utm_medium=banner
    ```
  </Accordion>

  <Accordion title="Start Small & Scale">
    * Book 1-2 hours first to test
    * Monitor click-through rates
    * Scale up what works
  </Accordion>

  <Accordion title="Writing Effective Article Titles">
    * Keep titles between 10-200 characters
    * Be specific and descriptive
    * Match the site's content focus
    * Use keywords relevant to the site's audience
    * If you have a great title, submit it directly (10+ chars)
  </Accordion>

  <Accordion title="Maximize Article Approval">
    * Research the site before submitting
    * Check recent articles for tone and topics
    * Tweet URLs work great - AI extracts context
    * Validate multiple ideas before paying
    * Score ≥70 required for approval
  </Accordion>

  <Accordion title="Leverage AI Suggestions">
    * If score is 70-89, review AI improvements
    * AI optimizes for SEO and engagement
    * Suggested descriptions enhance your submission
    * Use validation to refine your pitch
  </Accordion>
</AccordionGroup>

## Common Issues

<AccordionGroup>
  <Accordion title="'Insufficient balance' error">
    You need USDC on Base network. Check that:

    * You're connected to Base (Chain ID: 8453)
    * You have enough USDC for the total cost
  </Accordion>

  <Accordion title="'Time slot unavailable' error">
    Someone just booked that slot. Refresh and choose a different time.
  </Accordion>

  <Accordion title="Can I cancel a booking?">
    Currently, bookings cannot be cancelled or refunded. Make sure your ad is ready before booking.
  </Accordion>

  <Accordion title="Can I edit my ad after booking?">
    No, ad content is locked at booking time. You'll need to make a new booking to change it.
  </Accordion>
</AccordionGroup>

<Card title="Launch Your Campaign" icon="rocket" href="https://explorer.b3.fun/apps/x402-ad-marketplace">
  Start advertising on crypto sites in 5 minutes
</Card>

***

**Related:** [Article Submission Marketplace](/anyspend/marketplace-articles) • [x402 Overview](/anyspend/x402-overview) • [x402scan →](https://www.x402scan.com/server/ff37cb5f-7976-42bb-a161-e5e360d8cd42)