Earlier this month, many Bitcoin Core developers met up in Barcelona, Spain as part of their regular twice-yearly in person meetings.

Attendees volunteered to take notes on the unconference-style sessions and the transcripts have been added to the BTC transcripts website:

• AI session
• ASMap
• BIP324 and group policy options
• BIPs editors
• Bitcoin TUI
• CAmount
• CDash
• Coins cache
• Erlay redesign
• External interfaces
• GUI repo
• Inventory send queue
• Kernel (laundry list, overview, session)
• Libevent
• Logging
• Modern crypto library
• Mutation testing
• Package relay
• Post-cluster mempool
• Private broadcast
• QML (planning, update)
• Silent payments
• Static builds
• SwiftSync
• TCP hole punching
• Template hash

Additional informal discussions, code reviews, working groups, or other sessions occurred on:

• Quantum
• Determinism in testing
• Testnet5
• MEVPool
• Wallet priorities
• Silent payments
• Coins caching
• Peer observer
• ASMap updates
• IPC updates
• Utility binaries
• Bitcoin Kernel
• QML GUI
• Deterministic simulation testing
• AI assisted code review
• BIP39 import
• BIP54
• Fuzz testing
• Mutation testing
• Static builds
• FIBRE updates
• Parallel block input fetching

https://btctranscripts.com/bitcoin-core-dev-tech/2026-05

JD and Patricia (from localhost research), Emily (from Brink), and myself organized.

A list of previous meetings is here: https://coredev.tech

Thank you to all of the volunteer scribes for taking notes.