Block has joined the x402 Foundation and contributed Bitcoin Lightning support to the open payment protocol used by AI agents, web services and applications, the company announced on September 24, 2026. A code commit dated September 23 added what developers called “exact Lightning on lnbtc” to x402’s public repository, showing the technical work was already underway before the official disclosure.
x402, originally created by Coinbase and now overseen by the Linux Foundation, uses the HTTP 402 “Payment Required” response so software can request and settle payments during an ordinary web interaction. A server returns payment instructions when an AI agent requests a paid API, dataset or other digital service; the agent pays and retries with proof of payment.
Block said Lightning is suited to transactions that require low costs, fast settlement and repeated small payments. Steve Lee, head of Block’s Bitcoin development initiative Spiral, said agents “will make billions of small payments” and argued such activity needs payment rails designed for frequent, inexpensive transactions.
The x402 protocol already reports significant activity: 75.41 million transactions, $24.24 million in volume, 94,060 buyers and 22,000 sellers over the previous 30 days. Those figures cover x402 as a whole, not Bitcoin Lightning specifically. Stablecoins still dominate payment volume on x402; Circle has said USDC accounted for 99.3% of x402 payment volume in its most recent measured quarter. Lightning gives developers a way to settle directly in Bitcoin instead of a dollar-linked token.
The x402 Foundation became operational in July with 40 organizations. Premier members named in its launch materials include Amazon Web Services, Google, Coinbase, Mastercard, Visa, Stripe, Circle, Ripple, Shopify and the Solana Foundation. Block’s membership adds another major payments and Bitcoin-focused company to the effort.
Other network integrations have emerged around x402 in recent weeks. Cardano’s software stack received an early TypeScript release for testing, Casper mainnet uses an x402 facilitator, and XRP Ledger passed one million x402 transactions by July. Amazon Bedrock AgentCore added Coinbase’s x402 infrastructure for USDC payments, while The Graph uses x402 for pay-per-request blockchain data.
Block also pointed to existing agentic commerce work, including its open-source AI agent goose, involvement in the Agentic AI Foundation, and participation in Google’s Universal Commerce Protocol initiative. The company has not announced a timetable for adding Lightning-based x402 payments to consumer products such as Square, Cash App or Bitkey, but said it will continue contributing to Lightning support and participate in x402 Foundation working groups.
