x402 tag — page 1

Ordered by date created, newest first. Page 1 of 2; 17 publications total.

• Four-valued logic, sold per call: Belnap's logic as an x402 API 2026-10-21 · article
  Eight endpoints at $0.001 to $0.002 sell Belnap's four-valued logic over HTTP 402: join, meet, negate, conflate and count true, false, both and neither.
• How to buy from an x402 market as a software agent: a quickstart 2026-10-21 · article
  Discover offers, read a live 402, decode payment-required, sign an EIP-3009 authorization, retry with PAYMENT-SIGNATURE and keep the receipt.
• Causeway Services: x402 guides, a market where software pays, books, news and games 2026-10-21 · article
  Causeway Services runs an x402 market of 130 offers payable in USDC over HTTP 402, and publishes guides, books, Koios News and games. Start here.
• The 130-offer x402 market explained: what software can buy at market.561.group 2026-10-21 · article
  130 machine-payable offers in USDC on Base, from $0.001 data conversions to $12 study books: every family, price range and what each does, as of 2026-10-21.
• What is x402? HTTP 402 Payment Required for AI agents and APIs 2026-10-21 · article
  x402 is an open protocol that lets software pay for a web request in USDC by answering HTTP 402 Payment Required. How it works, who runs it, who uses it.
• Koios News: an AI-assisted newsroom with RSS feeds and a $0.25 x402 briefing 2026-10-20 · article
  Koios.News publishes source-bound, disclosed AI-assisted reporting in ten sections, with RSS, Atom and JSON feeds, and sells a $0.25 briefing over x402.
• How big is the x402 market? What the careful numbers say, October 2026 2026-10-18 · article
  Filtered x402 commerce is tens of millions of dollars, not hundreds; raw counts include wash trading and tests. Each figure with its source and date.
• Market, Bazaar and Shop: how the 561 Group's three storefronts relate 2026-10-18 · article
  market.561.group sells by x402, bazaar.561.group searches and compares 143 listings, shop.561.group sells books. Why shop-in-bazaar-in-market is a claim.
• How an x402 payment works, step by step: one request, one payment 2026-09-29 · article
  A single x402 payment in five steps: the 402 response, the signed EIP-3009 authorization, facilitator verify and settle, and the receipt. Version 2 headers.
• Is x402 legal? The GENIUS Act, sanctions and open questions for stablecoin payments 2026-09-29 · article
  The GENIUS Act regulates US stablecoin issuers, not x402 sellers; sanctions rules still apply to every payment. What the law settles and what remains open.
• The x402 Economy: a book sold for $9 in USDC over HTTP 402 2026-09-29 · article
  The x402 Economy is a 63-page book on HTTP 402 and the x402 market, sold for $9 in USDC through the protocol it explains. Contents and how to buy.
• What does HTTP 402 Payment Required mean? A history of the web's unused code 2026-09-29 · article
  HTTP 402 Payment Required was reserved in the web's standard in the 1990s and left unused for decades. Its history, why micropayments failed, and what changed.