MAJOR UPGRADE WITH DOWNTIME ON MAINNET WEDNESDAY 10 DECEMBER

1. #1Wayne Collier08-12-2025source ↗
   MainNet will go through a protocol-changing major upgrade on Wednesday, December 10th, starting at 9 am US Eastern (1400 UTC). Here are the most important things you need to know, and some recommendations on how to prepare.

   • MainNet will pause and go offline at the start of the major upgrade, 9 am US Eastern (1400 UTC)
   • MainNet will remain down between 3 and 6 hours
   • This major upgrade with downtime was approved by a vote of the Super Validators to adopt CIP-0089
   • The proven upgrade path is 0.4.23 -> 0.5.1. You must upgrade your Validator to 0.4.23 or 0.4.25 before the major upgrade.

    

   • Validators will stop processing transactions as soon as MainNet begins this pause.
   • To rejoin the network and resume processing transactions, Validators must complete the migration steps outlined in the technical documentation for Major Upgrades, here:
     • https://docs.sync.global/validator_operator/validator_major_upgrades.html
   • MainNet’s Migration ID will change as part of this upgrade. The Super Validators will announce the new Migration ID once MainNet comes back online. The default Migration_ID value will be 4, unless announced otherwise by the Super Validators.
   • Every node should take a full backup of its node and identities before the upgrade. Details here:
     • https://docs.sync.global/validator_operator/validator_backups.html#backups

   Important Points:

   • Before initiating the upgrade procedure, Validators should confirm that their nodes do not have any Ledger API users without party-level permissions
     • See the example provided here:
       • https://github.com/global-synchronizer-foundation/docs/discussions/19#discussioncomment-15013845

    

   • Traffic Balances go to zero after the upgrade.  Validators will not retain traffic balances after the upgrade, and will restart with zero traffic. Consider reducing your topup amount to minimize lost traffic. 

    

   • Exchanges and other Application Providers should read closely through the additional guidance provided here:
     • https://docs.digitalasset.com/integrate/devnet/exchange-integration/node-operations.html#rolling-out-major-splice-upgrades
   • The proven upgrade path for this upgrade is Splice 0.4.23 -> Splice 0.5.1.  All Validators must upgrade to Splice 0.4.23 before the upgrade.
     • Upgrading to Splice 0.4.25 is optional; the 0.4.25 -> 0.5.1 upgrade path will also succeed.

   Note that, as outlined in the long-term schedule, this major upgrade will be followed immediately by a minor (non-forking) upgrade to Splice 0.5.4.