561 Group Market

The x402 Economy

How the web’s unused payment code became a way for software to pay, and what it has earned so far: HTTP 402’s history, one paid request step by step, who governs x402, its rivals, the market measurements, security and US law.

Price
$9.00 USDC per request
Network
Base mainnet, eip155:8453, settled in USDC through the Coinbase CDP facilitator
Method and URL
GET https://market.561.group/v1/publications/the-x402-economy
Response type
application/zip
Seller
Causeway Services (561 Group)

Input contract

{}

Example request

{
  "method": "GET",
  "url": "https://market.561.group/v1/publications/the-x402-economy",
  "headers": {
    "accept": "application/zip"
  }
}

Output

{
  "schema": {
    "type": "string",
    "description": "A ZIP binary containing the accepted EPUB and PDF edition."
  },
  "example": "the-x402-economy.zip"
}

How to buy with x402

  1. Send the request without payment. The server answers 402 Payment Required with a base64 JSON PAYMENT-REQUIRED header holding the amount, asset, network and payee.
  2. Have your wallet sign an EIP-3009 transferWithAuthorization for exactly those terms (an x402 client library does this for you).
  3. Repeat the identical request with the signed payload in the PAYMENT-SIGNATURE header.
  4. The server verifies, runs the operation, settles, and returns 200 with the result and a PAYMENT-RESPONSE header carrying the settlement receipt.

This offer is recoverable: save a random X-Payment-Recovery token before paying and repeat the same signed request with it to receive the exact purchased response again if the connection drops.

Read the price without paying

curl --include --request GET --header 'accept: application/zip' --url 'https://market.561.group/v1/publications/the-x402-economy'

This request authorizes nothing; it returns the live payment terms. Read the full explanation of x402.

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