Canton 3.4 to Canton 3.5 Transition

Please review the latest update for the Canton 3.4 to Canton 3.5 transition.

Update date: 2026-06-08
Full details are available in the long-term SV Operations schedule.

Phase 1

Complete

Phase 2

Daml models from Splice 0.6.2 take effect on MainNet.

MainNet validators must upgrade before:
2026-06-09

Minimum required version:
Splice 0.6.2

Phase 3

All three Global Synchronizer networks will perform a Logical Synchronizer Upgrade to Canton Protocol Version 35.

Minimum Splice version for validators:
Splice 0.6.5

DevNet

Topology Freeze: 2026-06-09
Upgrade: 2026-06-10

TestNet

Topology Freeze: 2026-06-16
Upgrade: 2026-06-17

MainNet

Topology Freeze: 2026-06-26
Upgrade: 2026-06-27

All Phase 3 events are scheduled for 9:00 AM US Eastern / 13:00 UTC.

App Provider Impact During LSUs

During Logical Synchronizer Upgrades:
- Party onboarding, package vetting, and other topology transactions will pause for 24 hours before the LSU
- These actions will resume immediately after the LSU completes
- Daml transactions may 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 are currently expected to go live on MainNet at the end of July.

Based on the current plan, this will require validator nodes to upgrade to Splice 0.6.11.

Important Dates

July 1: Dry run of traffic-based app rewards goes live on MainNet
TBD July: MainNet switches to traffic-based app rewards, with the final date depending on production trading dry run schedules during July @Dev Announcements @Product Updates