Welcome to BNBPAYAI

this guide will help you understand BNBPAYAI, the x402 payment standard implementation on BNB Chain, and help you get started building or integrating services with accountless payments.

BNBPAYAI is built on the open x402 payment standard that enables services to charge for access to their APIs and content directly over HTTP. it is built around the HTTP 402 Payment Required status code and allows clients to programmatically pay for resources without accounts, sessions, or credential management.

with BNBPAYAI, any web service can require payment before serving a response, using crypto-native payments on BNB Chain for speed, privacy, and efficiency.

Why Use BNBPAYAI?

BNBPAYAI addresses key limitations of existing payment systems:

Who is BNBPAYAI for?

What Can You Build?

BNBPAYAI enables a range of use cases on BNB Chain:

• API services paid per request - monetize your APIs with per-call pricing
• AI agents that autonomously pay for API access - enable AI to use premium tools
• paywalls for digital content - protect premium content behind payments
• microservices and tooling monetized via microtransactions - charge tiny amounts for specific operations
• proxy services that aggregate and resell API capabilities - build marketplaces for API access

How Does It Work?

at a high level, the flow is simple:

1. a buyer requests a resource from a server
2. if payment is required, the server responds with 402 Payment Required, including payment instructions
3. the buyer prepares and submits a payment payload with the BNB Chain transaction
4. the server verifies the payment on BNB Chain
5. if payment is valid, the server provides the requested resource

// Example: Client making a paid API request
const response = await fetch('https://api.example.com/analyze', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x402-payment': '0.005' // Payment amount in USDC
  },
  body: JSON.stringify({ data: 'analyze this' })
});

if (response.status === 402) {
  console.log('Payment required');
} else {
  const result = await response.json();
  console.log('Service result:', result);
}

HTTP 402 Payment Required

the HTTP 402 status code was reserved for future payment systems. BNBPAYAI uses this standard to signal that payment is required for a resource.

Response Format

HTTP/1.1 402 Payment Required
Content-Type: application/json

{
  "error": "Payment required",
  "amount": "0.005",
  "currency": "USDC",
  "network": "bsc-testnet",
  "description": "Data analysis service"
}

BNB Chain Integration

BNBPAYAI is built specifically for BNB Chain, offering several advantages:

Weather API (Free)

a free API to demonstrate the system without requiring payment.

Endpoint

Example Request

curl "http://localhost:3000/api/weather?city=London"

Example Response

{
  "city": "London",
  "temperature": "15°C",
  "condition": "Partly Cloudy",
  "humidity": "65%",
  "wind": "12 km/h"
}

Data Analysis API

advanced data analysis service requiring payment of 0.005 USDC.

Endpoint

Headers Required

• x402-payment: 0.005
• Content-Type: application/json

Example Request

curl -X POST http://localhost:3000/api/analyze \
  -H "x402-payment: 0.005" \
  -H "Content-Type: application/json" \
  -d '{"data": "Sample data", "analysisType": "sentiment"}'

Example Response

{
  "success": true,
  "analysis": {
    "sentiment": "positive",
    "confidence": 0.92,
    "keyPoints": ["Point 1", "Point 2"]
  },
  "transactionId": "0x..."
}

Image Generation API

AI-powered image generation requiring payment of 0.01 USDC.

Endpoint

Headers Required

• x402-payment: 0.01
• Content-Type: application/json

Request Body

{
  "prompt": "A futuristic city at sunset",
  "style": "realistic",
  "size": "1024x1024"
}

AI Agents with x402

BNBPAYAI enables AI agents to autonomously pay for and use premium services. agents can:

• detect when payment is required (402 status)
• calculate the cost-benefit of using a paid service
• authorize and execute payments on BNB Chain
• utilize the service and continue their task

Setup & Configuration

Prerequisites

• Node.js 18+
• Coinbase CDP account
• API keys (optional for AI features)

Installation

# Clone the repository
git clone https://github.com/yourusername/BNBPAYAI
cd BNBPAYAI

# Install dependencies
npm install

# Configure environment
cp env.example .env.local

# Run development server
npm run dev

Environment Variables

# Coinbase CDP Configuration
CDP_API_KEY_ID=your_api_key_id
CDP_API_KEY_SECRET=your_api_key_secret
CDP_WALLET_SECRET=your_wallet_secret

# Network (use bsc-testnet for development)
NETWORK=bsc-testnet

# AI Configuration (Optional)
OPENAI_API_KEY=your_openai_key
ANTHROPIC_API_KEY=your_anthropic_key

Deployment

Deploy to Vercel

1. push your code to GitHub
2. connect your repository to Vercel
3. add environment variables in Vercel dashboard
4. deploy

Moving to Mainnet

when ready for production:

1. change NETWORK=bsc in environment variables
2. fund your wallet with real USDC on BNB Chain
3. test thoroughly
4. monitor transactions and costs

Get Started

ready to build with BNBPAYAI on BNB Chain?