Originally reported by ChainCatcher on November 13, 2026, at 08:27 (UTC+8), citing Crypto Briefing.
Lightning Labs released pi402, an open-source extension for the Pi coding agent, on November 12. It lets an agent use Bitcoin over the Lightning Network to pay for its own inference costs without registering an account or supplying an API key or credit card.
The payment flow uses the L402 protocol: the agent receives an HTTP 402 “Payment Required” response and a Lightning invoice, pays it, then resumes work. The reported model charges agents according to the tokens they actually consume. Sellers can accept payments using Aperture and Lightmeter; neither buyers nor sellers need to run a Lightning node because payments are handled by the Ark-based Wavelength wallet.
The reported demo prices were approximately $0.375 per million input tokens and $1.50 per million output tokens.