The x402 Foundation merged pull request #2861 into its x402 spec on September 23, 2026, defining how to use x402 with Bitcoin Lightning payments. Maintainer phdargen merged the change, titled "docs: Specify exact Lightning on BIP-122", and posts from Spiral and Bitcoin News corroborated the merge the same day.

What the Merged Spec Defines

PR #2861 defines how to use x402 with Bitcoin Lightning payments, which gives Lightning a written place inside the x402 spec instead of an informal add-on. The pull request thread reads as a detailed spec review about request-binding, replay protection, and unit semantics.

Request-binding, replay protection, and unit semantics decide whether a paid request stays tied to one payment, whether that payment can be reused, and what unit a price is quoted in. A detailed spec review of those three topics shows the x402 Foundation treated Lightning as a spec question, not a marketing checkbox.

Lightning payments under x402 are proven via the payment preimage, according to Bitcoin News. Proof via the payment preimage means the server checks the Lightning payment itself rather than waiting on a card network or a custodian to confirm it.

Who Sits Around the x402 Table

According to Bitcoin News, x402 was originally built by Coinbase and is now governed via the Linux Foundation. The same post lists Cloudflare, Google, AWS, Visa, Mastercard, Stripe, and American Express as participants.

That roster puts Bitcoin Lightning payments inside a spec shaped by cloud providers, card networks, and payment processors. PR #2861 places Bitcoin Lightning payments inside that x402 spec alongside the companies participating in its governance via the Linux Foundation.

A developer already building on x402 now finds how to use x402 with Bitcoin Lightning payments defined in the same spec, merged by maintainer phdargen on September 23, 2026.

Why It Matters

Bitcoin Breakdown reads the merge of PR #2861 as a settlement win, because x402 now defines how to use Bitcoin Lightning payments inside a spec governed via the Linux Foundation with Cloudflare, Google, AWS, Visa, Mastercard, Stripe, and American Express participating. Lightning payments under x402 are proven via the payment preimage, which means a server verifies settlement itself instead of asking an issuer or a card network for permission. Because x402 was originally built by Coinbase and is now governed via the Linux Foundation, defining Bitcoin Lightning payments inside it puts Bitcoin alongside other rails rather than isolating it in a Lightning-only niche. Among those rails, Lightning is the one that settles in bitcoin, a money no participant on that list can issue.