Canton 3.4 to canton 3.5 transition

Update: 2026-06-12
See details in the long-term SV Operations schedule

Phase 1: Complete

Phase 2: Complete

Phase 3: Upgrade Global Synchronizer networks to Canton Protocol 35

• All three Global Synchronizer networks will perform a Logical Synchronizer upgrade (LSU) to Canton protocol Version 35.
• Minimum Splice Version for Validators for this Upgrade: Splice 0.6.5
• Dates: (All events at 9 am US Eastern / 1300 UTC)
  • DevNet: LSU from protocol version (PV) 34 to 35 on DevNet: Complete
  • TestNet: LSU for PV 34->35
    • Toplogy Freeze: 2026-06-16 1300 UTC
    • Upgrade: 2026-06-17 1300 UTC
  • MainNet: LSU for PV 34->35
    • Toplogy Freeze: 2026-06-26 1300 UTC
    • Upgrade: 2026-06-27 1300 UTC

App Provider Experience during Logical Synchronizer Upgrades (LSUs):

• All party onboarding, package vetting and other topology transactions will pause for 24 hours before the LSU, and will resume immediately after the LSU completes.
• Daml transactions will be delayed for seconds to minutes at the moment of the LSU
• App providers should experience no other impact.

Also Coming in Phase 3:
Traffic-based App Rewards go live on the following schedule:

• June 30th: Daml models from Splice 0.6.7 become effective on MainNet. All nodes must upgrade to Splice 0.6.7 before this date.
• July 7th: Dry Run of Traffic-based app rewards begins on MainNet.
• July 28th: Traffic-based app rewards go live on Mainnet
  • This tentatively will require upgrading Validator nodes to Splice 0.6.9, though the final version number is to be confirmed.

Phase 4: Retire CometBFT

• The Canton team has prepared a new Canton-native BFT ordering service to replace CometBFT.
• LSUs to adopt CantonBFT are tentatively as follows. All times 1300UTC, with Topology Freeze set 24 hours earlier.
  • DevNet LSU
    • Wednesday, July 8th
  • TestNet LSU
    • Wednesday, July 22
  • MainNet LSU
    • Saturday, August 8th