I really like the localhost research updates. The good people there posted this update last week and it makes for impressive reading.

First off, these people must spend a ton of time travelling: TabConf in Atlanta, CoreDev in Frankfurt, Bitcoin Research Week in New York, BitDevs Lima, and Bitcoin Builders in Palo Alto. Real world meetings of Bitcoiners are one of the most hopeful things about Bitcoin -- and seeing highly knowledgeable folks take the time to show up and share their knowledge is really great!

Second, if you've been living under a rock, maybe you haven't noticed, but otherwise, you've probably been hearing lots of new BIP numbers. This is because the BIP editors have been on fire! Lots of proposals for Bitcoin getting introduced into the BIP repo. Check 'em out:

• BIP446: OP_TEMPLATEHASH and BIP Draft: TH+CSFS+IK Bundle
• BIP442: OP_PAIRCOMMIT
• BIP 181, 182, 183: BIPs for Utreexo
• BIP153: SENDTEMPLATE 
• BIP 110: Reduced Data Temporary Softfork
• BIP 433: Add P2A BIP

And there was also BIP 3 (#1281384, #1411654), @murch's proposal to update the BIP Process.

Third, the localhost research team made a lot of contributions to Bitcoin Core, including work on backporting the default minimum feerate to v28.3, a network policy rule that had become the source of significantly degraded performance of Compact Block Relay. Localhost also did a lot of work on v30.

Ava Chow successfully merged a PR that enabled Bitcoin Core to receive and spend inputs involving MuSig2 aggregate keys. As far as I know, MuSig2 (#1277093) support is only in a few other wallets (Nunchuck, BitBox Swiss and Ledger). So this is very cool to see!

Some other highlights from the localhost team's work on Core are:

• contributor ishaanam opened a PR to support v3 transactions in the Bitcoin Core wallet.
• Ava opened a PR that ensures the Bitcoin Core wallet correctly identifies and handles P2A and ephemeral dust outputs (#1426939)
• Pol has been working towards migrating Bitcoin Core away from representing fees in BTC/kvB to sat/vB
• David’s work on Compact Block prefills continues. He further elaborated on his prefill strategy in the ongoing Delving Bitcoin thread and has made headway on the implementation. He continues to collect data from nodes running this branch and is working toward opening a pull request to Bitcoin Core.
• w0xlt has been an active contributor to the secp256k1 repository, participating in review of the Silent Payments module as well as some smaller PRs, one of which he inspired.
• Pol (with extensive help from w0xlt) tasked himself with building a proof-of-concept version of the MACT (marketplace-aware custom templater) block builder. Described in the MEVPool Paper (#891316). Pol and w0xlt shipped their proof of concept MACT. Along the way, they were able to contribute upstream to Bitcoin Core’s libbitcoinkernal project.
• w0xlt authored #33796 which introduces context-free consensus checks on a transaction structure. Similarly, w0xlt’s #33908 enables context-free validation of a block’s structure. Both of these PRs are still actively being reviewed and iterated on.
• w0xlt and Justin made progress towards the release of FIBRE (#1438268, #1442845) throughout the second half of 2025. w0xlt completed a rebase against v30 and added various metrics and USDT tracepoints to the project. Justin prepared the FAQ for the FIBRE website. The project is now live.

Reading through each one of these localhost updates is an education in Bitcoin. They are packed with links and the process of going through them and trying to understand all the things localhost is working on will keep you up to date. Highly recommended reading!