Block, the payments company led by Jack Dorsey, has joined the x402 Foundation and contributed Bitcoin Lightning Network support to the open standard that allows AI agents and web services to handle payments automatically. The company disclosed the step on September 24, stating that Lightning suits the low-cost, fast-settlement, high-volume transactions expected in agentic commerce.

A public repository commit dated September 23 recorded the addition of exact Lightning support using the lnbtc network identifier, providing a technical record ahead of the formal announcement. The contribution expands the payment options available inside the x402 framework beyond the stablecoin methods that have dominated early activity.

How the x402 Protocol Operates

x402 was originally developed by Coinbase and later contributed to the Linux Foundation. The protocol uses the HTTP 402 “Payment Required” response so that a server can return payment instructions when an AI agent requests a paid API, dataset or other digital resource. The agent completes the payment and retries the request with proof of settlement.

The standard is designed to remain network- and currency-agnostic. Merchants can accept multiple settlement systems through the same payment middleware without building separate integrations for every agent platform. Official figures from the protocol show 75.41 million transactions and $24.24 million in volume over the preceding 30 days, along with 94,060 buyers and 22,000 sellers. Those totals cover all payment methods currently supported and are not specific to Lightning.

Stablecoins have accounted for the large majority of activity to date. Circle reported that USDC represented 99.3 percent of measured x402 payment volume during the second quarter.

Lee also noted that agents “will make billions of small payments,” requiring rails priced for frequent, inexpensive transfers. Block described Lightning as purpose-built for instant, low-cost, high-volume flows of the kind machine-to-machine commerce is expected to generate.

Foundation Governance and Membership

The Linux Foundation announced the x402 Foundation in April as a neutral body to steward the standard outside any single vendor’s control. The foundation became operational in July with 40 organizations. Premier members listed at launch included Amazon Web Services, Google, Coinbase, Mastercard, Visa, Stripe, Circle, Ripple, Shopify and the Solana Foundation.

Microsoft appeared among companies expressing initial intent and support in the April notice but was not included in the July operational roster of 40 members. The protocol’s documentation states that different networks can be added without tying the standard to one payment rail.

Block’s entry places Lightning alongside existing options inside a consortium that already includes card networks, cloud providers and crypto-native firms. The company has not published Lightning-specific transaction volumes, merchant deployments or AI-agent usage figures tied to its contribution.

Broader Agentic Commerce Context

The move extends work Block has already pursued around autonomous software. The company has contributed its open-source AI agent goose, helped establish the Agentic AI Foundation and participates in the Universal Commerce Protocol, an open standard that connects consumer-facing AI systems with merchant infrastructure for product discovery, checkout and payment selection.

x402 addresses a different layer of the stack: the payment request and settlement interaction over ordinary HTTP, including cases in which an agent purchases a single API call or digital resource without a conventional checkout flow. Block said open payment rails can let sellers interact with buyers’ agents without creating separate integrations for every platform.

Other networks have already begun integrating the standard. An x402 implementation on Cardano remains in pre-production testing. Autonomous payment infrastructure using an x402 facilitator is live on Casper mainnet. Activity on the XRP Ledger passed one million x402 transactions by July.

Block has announced no timetable for integrating Lightning-based x402 payments into Square, Cash App, Bitkey or its other consumer products. Its September 24 roadmap commits the company to continued Lightning contributions, participation in x402 Foundation working groups and further development of agentic-commerce tools that use the standard.