x402_pay 1.0.0-beta1

First beta of x402 Pay: Drupal charges for content and API calls in USDC on Arc over HTTP 402, following the x402 protocol. No accounts, no checkout: an agent (or a person's wallet) gets a 402 with the price, signs a payment, and gets the response.

What's in it

• The payment gate (x402_pay.gate): any controller can charge per request. Verify, run the handler, and settle only when the response is a 2xx, so a failed call costs the buyer nothing. A payment log keeps route, amount, payer and transaction hash; a Server-Timing header says where the time went.
• The x402_price field: add it to any fieldable entity and its content is for sale. Each field sells one view mode at a price; several fields sell several (full text, summary). Per entity price overrides, a price per translation, and a switch to sell for free.
• Agents pay, browsers browse: on the entity's own URL, requests from agents (a payment header, a non-HTML Accept, or a known AI user agent) get the 402 while people still see the page. Every product also lives at /x402/{entity_type}/{id}/{view_mode}, announced with Link headers. Buyers receive the view mode's fields as Markdown.
• Discovery: /x402/discovery lists everything for sale in the shape of Circle's Discovery API, so marketplace clients read it unchanged. For people, a Views filter (Charge for this) and a price formatter.
• Events: PriceEvent before every sale (change the price, make it free, deny it, choose the seller wallet, set the timeout) and DeliveryEvent to answer with something else than Markdown, e.g. a paid API call.
• Three ways to settle, per network, at Configuration → Web services → x402 Pay:
  • Circle's facilitator, keyless trial (each sale signed by the seller's key).
  • Circle's facilitator with an API key: sellers can be plain addresses, no key on the site.
  • The site's own facilitator: Drupal sends the buyer's signed transferWithAuthorization on chain from a gas wallet that pays only the gas. No third party.
• Sweeping: seller keys kept on the site can be emptied to a cold wallet on cron or with drush x402:sweep [--dry-run], so a compromised site loses at most what arrived since the last sweep.
• Networks: Arc mainnet (eip155:5042) and Arc testnet (eip155:5042002).

Security

• Keys only through the Key module, from environment variables; never in exportable configuration.
• EIP-712 hashing, secp256k1 signing and EIP-1559 transactions in PHP, equal byte for byte to viem (test vectors included).
• The page cache never hands a paid response to an unpaid request (covered by a functional test).
• Permissions: Set x402 prices, Access x402 content free, Administer x402 Pay.

Known limits

• The x402 exact scheme on Arc only; other EVM chains and Solana are planned.
• The own facilitator accepts plain wallet (EOA) signatures; smart-contract wallets (ERC-1271) are planned.
• Coming: a Drupal Commerce gateway (x402_pay_commerce) and ECA integration (x402_pay_eca).
• Beta: APIs and configuration may change before 1.0.0.

Requires Drupal ^11.1 || ^12, PHP 8.3+ with ext-gmp, and the Key module.