ElementsProject/lightning v25.12rc2

v25.12rc2 Boltz's Seamless Upgrade Experience

on GitHub

Release Candidate 2 for Core Lightning v25.12

This release has been named by @sangbida

Highlights for Users

• This release candidate includes a downgrade tool! lightningd-downgrade will downgrade your database from v25.12 to v25.09 if something goes wrong
• New nodes will now be created with a BIP-39 12-word phrase as their root secret. BIP-39 12-word base functionality in lightning-hsmtool to support hsm_secret files.
• We received great feedback about xpay and adjusted accordingly: which will no longer try to send too many HTLCs through unknown channels (6, as that is Phoenix's limit) unless it has no choice, we've fixed a clash with simultaneous payments via routehints and blinded paths and asked xpay to wait if it suspects a payment failure is due to a height disagreement with the final node.
• Added askrene-bias-node: an RPC command to set a bias on node's outgoing or incoming channels.
• Use the new networkevents subsystem to access information about peers: ping times and connection times.
• We've configured an experimental-lsps-client and experimental-lsps2-service support for LSPS level 2 specification.

Highlights for Developers

There's a vast array of performance improvements for large nodes... go directly to the change log!

• Multiple significant speedups for large nodes have been added to lightningd, especially preventing "freezes" under exceptionally high load and helping it to handle large numbers of command outputs gracefully.
• xpay will not try to send too many HTLCs through unknown channels (6, as that is Phoenix's limit) unless it has no choice
• Postgres: significant speedup on read-only operations (e.g. 30% on empty SELECTs)

Protocol Updates

• We now re-transmit unseen funding transactions on startup, for more robustness.
• Stricter conformance to Bolt spec for splice commitments.

See the changelog for full details

Since 25.09 we’ve had 480 commits in 82 days by 23 authors
A special thanks to our three first time contributors:

@noblepayne
@claudio.raimondi@pm.me
@botantony

An enormous thanks to the Core Lightning team:
@rustyrussell, @ShahanaFarooqui, @sangbida, @endothermicdev, @cdecker, @nepet, @Lagrang3, and @niftynei