The Book of ₿itcoin Field Noteshttps://www.bookofbitcoin.org/field-notes/Sourced reports on Bitcoin, blockchains and AI agents.en 138 Million x402 Transactions on Base: What the Count Meanshttps://www.bookofbitcoin.org/field-notes/ai-agent-payments-138-million/https://www.bookofbitcoin.org/field-notes/ai-agent-payments-138-million/2026-10-17Chainalysis counted over 138 million x402 transactions on Base. What the figure measures, what it misses, and why volume alone is not proof of broad demand. Why Is My Bitcoin Transaction Taking So Long? Fees and Confirmationshttps://www.bookofbitcoin.org/field-notes/bitcoin-confirmations-explained/https://www.bookofbitcoin.org/field-notes/bitcoin-confirmations-explained/2026-10-17Why a Bitcoin payment may stay pending, how to check its transaction ID and fee, and when wallet-supported fee bumping may help. Bitcoin Halving, Explained: The Block Reward Gets Cut in Halfhttps://www.bookofbitcoin.org/field-notes/bitcoin-halving-explained/https://www.bookofbitcoin.org/field-notes/bitcoin-halving-explained/2026-10-17Bitcoin's subsidy halves every 210,000 blocks. Here is what that means for new supply, transaction fees, miners, and the next scheduled change. Bitcoin Recovery Phrases, Explained: What the Words Can Restorehttps://www.bookofbitcoin.org/field-notes/bitcoin-recovery-phrases-explained/https://www.bookofbitcoin.org/field-notes/bitcoin-recovery-phrases-explained/2026-10-17How a BIP 39 recovery phrase is built, what a compatible wallet can restore, and why losing or exposing the words changes the risk. Bitcoin ETFs: The 10-Year Wait, and the Judge Who Asked for Homeworkhttps://www.bookofbitcoin.org/field-notes/bitcoin-spot-etf-timeline/https://www.bookofbitcoin.org/field-notes/bitcoin-spot-etf-timeline/2026-10-17How spot Bitcoin ETFs got approved in the US, from a 2013 filing to January 2024. Every date has a source and the fuzzy parts are marked. Can AI Agents Pay With Bitcoin? Short Answer: They'd Rather Use Dollarshttps://www.bookofbitcoin.org/field-notes/can-ai-agents-pay-with-bitcoin/https://www.bookofbitcoin.org/field-notes/can-ai-agents-pay-with-bitcoin/2026-10-17AI agents are getting wallets. Three standards (x402, L402, AP2) decide how they pay. Who does what, in plain words, and which numbers we trust. Lightning Network Payments, Explained: Bitcoin's Side Streetshttps://www.bookofbitcoin.org/field-notes/lightning-network-payments-explained/https://www.bookofbitcoin.org/field-notes/lightning-network-payments-explained/2026-10-17How Lightning channels, invoices, routing, and liquidity fit together, plus the practical limits that can make a payment wait or fail. Stablecoins and the GENIUS Act: What the Law Sayshttps://www.bookofbitcoin.org/field-notes/stablecoins-genius-act-explained/https://www.bookofbitcoin.org/field-notes/stablecoins-genius-act-explained/2026-10-17What the GENIUS Act requires of US payment stablecoin issuers, when parts take effect, and what reserve rules do not guarantee.