[Lightning Labs Launches pi402, Allowing AI Agents to Pay Inference Fees with Bitcoin] According to Crypto Briefing, Lightning Labs released the open-source extension pi402 on November 12th, enabling AI programmable agents to pay their inference fees using Bitcoin via the Lightning Network. This tool is specifically built for Pi programmable agents and requires no account registration, API key, or credit card. The agent simply pays the invoice after seeing the price and resumes operation. pi402 is based on the L402 protocol, combining an HTTP 402 "Payment Required" response with a Lightning Network invoice, allowing for instant settlement after the agent's payment. This implements a token-based billing model, where agents pay based on actual consumption. Sellers can accept payments through Aperture and Lightmeter tools; neither buyer nor seller needs to run a Lightning node, and payments are processed by an Ark-based Wavelength wallet.