Block adds Bitcoin Lightning support to x402 payment standard

The Defiant reported that Block joined the x402 Foundation on Sept. 24, contributing a Bitcoin Lightning payment specification. The standard enables AI agents to pay for web services using the HTTP 402 status code.

Under the new specification, services issue Lightning invoices. Clients settle these invoices by returning a cryptographic secret known as a preimage. A facilitator verifies the proof without accessing the recipient’s Lightning node. Payers are responsible for Lightning routing fees, and the scheme includes no refund mechanism. To stop the same preimage proof from being redeemed a second time, payments must be marked as used.

Premier members of the x402 Foundation include Amazon Web Services, Google, and Coinbase. Block noted that the standard operates under the Linux Foundation’s governance.

A Python implementation proposed in pull request 1873 is currently in draft status. Its tests have not used real-money payments, and the author stated that interop checks against actual Lightning nodes remain pending. Carman, who wrote the specification, said the integration offers an alternative to stablecoins within the same standard.

“I would prefer L402, but this allows for people using x402 with other coins to at least have the option of adopting lightning instead of needing a whole new system,” Carman wrote on X.

Block intends to keep working on Lightning support and join the foundation’s working groups over the coming months.