https://www.bookofbitcoin.org/field-notes/Sourced reports on Bitcoin, blockchains and AI agents.en https://www.bookofbitcoin.org/field-notes/who-can-switch-off-a-robots-money/https://www.bookofbitcoin.org/field-notes/who-can-switch-off-a-robots-money/2026-10-28Dollar-style coins can be frozen by the company behind them, and a US law says issuers must be able to. What the documents say, and what they do not settle about Bitcoin. https://www.bookofbitcoin.org/field-notes/why-ai-agents-prefer-stablecoins/https://www.bookofbitcoin.org/field-notes/why-ai-agents-prefer-stablecoins/2026-10-27Dollar budgets help explain stablecoin checkout. Compare spending, saving and tiny Bitcoin payments without crowning a winner. https://www.bookofbitcoin.org/field-notes/self-custody-basics/https://www.bookofbitcoin.org/field-notes/self-custody-basics/2026-10-23What "not your keys, not your coins" means, plus the plain checklist Bitcoin.org gives for holding your own bitcoin: backups, passwords and offline savings. https://www.bookofbitcoin.org/field-notes/what-is-a-stablecoin/https://www.bookofbitcoin.org/field-notes/what-is-a-stablecoin/2026-10-21A stablecoin is a digital promise. Primary documents explain who owes the money, what reserves support it, and why backing is no government guarantee. https://www.bookofbitcoin.org/field-notes/mt-gox-deadline-moved-to-2027/https://www.bookofbitcoin.org/field-notes/mt-gox-deadline-moved-to-2027/2026-10-19The Mt. Gox trustee moved the repayment deadline from October 31, 2026 to October 31, 2027. What the notice says, earlier delays, and what we cannot tell. https://www.bookofbitcoin.org/field-notes/what-is-bitcoin-plain-words/https://www.bookofbitcoin.org/field-notes/what-is-bitcoin-plain-words/2026-10-18Bitcoin is digital money shared across a network. Here is how transactions, keys and the public ledger fit together, without the jargon parade. https://www.bookofbitcoin.org/field-notes/ai-agent-payments-138-million/https://www.bookofbitcoin.org/field-notes/ai-agent-payments-138-million/2026-10-17A research firm counted 138 million payments made by AI helpers on one network. Most were pennies. What the report says, what it does not, and the "who is this robot?" problem. https://www.bookofbitcoin.org/field-notes/bitcoin-halving-explained/https://www.bookofbitcoin.org/field-notes/bitcoin-halving-explained/2026-10-17What the Bitcoin halving is, when each one happened, and why the last coin arrives around 2140. Plain words, real dates, and one honest guess. https://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. https://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 helpers are getting wallets. Three new tools decide how they pay: two cash registers and one permission slip. What each does, in plain words, and which numbers we trust. https://www.bookofbitcoin.org/field-notes/stablecoins-genius-act-explained/https://www.bookofbitcoin.org/field-notes/stablecoins-genius-act-explained/2026-10-17The US passed a stablecoin law in July 2025. Here is what it says in plain words, what we could not verify, and why it matters for Bitcoin and AI agents.