This week’s newsletter includes our regular sections summarizing popular questions and answers from Bitcoin Stack Exchange, announcing new software releases and release candidates, and describing recent changes to Bitcoin infrastructure software.

News

No significant news this week was found on the Bitcoin-Dev or Lightning-Dev mailing lists.

Selected Q&A from Bitcoin Stack Exchange

Bitcoin Stack Exchange is one of the first places Optech contributors look for answers to their questions—or when we have a few spare moments to help curious or confused users. In this monthly feature, we highlight some of the top-voted questions and answers posted since our last update.

• ● What is the purpose of indexing the mempool by these five criteria? Murch and glozow explain the different mempool transaction indexes (txid, wtxid, time in mempool, ancestor feerate, and descendant feerate) in Bitcoin Core as well as their usages.

• ● BIP-341: Should key-path-only P2TR be eschewed altogether? Pieter Wuille defines 4 taproot keypath spend options, outlines why BIP341 recommends the “noscript” option, and notes scenarios where other options might be preferred.

• ● Was the addition of OP_NOP codes in Bitcoin 0.3.6 a hard or soft fork? Pieter Wuille explains that the addition of OP_NOP codes in Bitcoin Core 0.3.6 was a backward incompatible consensus change since older software versions would see transactions with the newly valid OP_NOP codes as invalid. However, since no transactions using these OP_NOP codes were previously mined, there was no actual fork.

• ● What is the largest multisig quorum currently possible? Andrew Chow lists the different possible multisig types (bare script, P2SH, P2WSH, P2TR, P2TR + MuSig) and the multisig quorum restrictions for each.

• ● What is the difference between blocksonly and block-relay-only in Bitcoin Core? Lightlike lists the differences between block-relay-only connections and a node running in -blocksonly mode.

• ● Where are BIPs 40 and 41? User andrewz asks why assigned BIP numbers BIP40 for Stratum wire protocol and BIP41 for Stratum mining protocol have no content. In a separate answer, Michael Folkson links to some work-in-progress Stratum documentation links.

Releases and release candidates

New releases and release candidates for popular Bitcoin infrastructure projects. Please consider upgrading to new releases or helping to test release candidates.

• ● LND 0.15.0-beta is a release for the next major version of this popular LN node. It adds for invoice metadata which can be used by other programs (and potentially future versions of LND) for stateless invoices and adds support to the internal wallet for receiving and spending bitcoins to P2TR keyspend outputs, along with experimental MuSig2 support.

• ● Core Lightning 0.11.2 is a bug fix release of the LN node. Upgrading is “highly recommended” by the Core Lightning developers.

Notable code and documentation changes

Notable changes this week in Bitcoin Core, Core Lightning, Eclair, LDK, LND, libsecp256k1, Hardware Wallet Interface (HWI), Rust Bitcoin, BTCPay Server, BDK, Bitcoin Improvement Proposals (BIPs), and Lightning BOLTs.

• ● Core Lightning #5306 updates multiple APIs to consistently use the name “msat” for millisatoshis and also returns JSON values in those fields as numbers. Some fields are renamed to provide consistencies with other fields. The old behavior is deprecated and so will remain available temporarily.

• ● LDK #1531 begins using anti fee sniping for LN funding transactions.