26th May 2026

Agenda

1. Action items from the last call - Bosko

2. Node 11.0.1 & DBSync 13.7.1.0 - Sam/Ramsay/Jeff

   1. 13.7.1.0/13.7.0.5 with fix/workaround

      1. How does it affect ecosystem?

      2. Does this delay hard fork?

3. Van Rossem Upgrade Update - Bosko, all

   1. Ogmios PR

      1. van Rossem only support vs van Rossem & Dijkstra support

   2. Kupo PR #1 & PR#2

      1. Potential alternative path to progress without explicit need for Ogmios? - Sam

   3. Community feedback on Plutus - Kevin, Sam

      1. Casing on Builtins in UPLC

   4. Readiness tracker

4. van Rossem hard fork progress - Bosko

   1. PreProd

      1. Cardanoscan

      2. Cexplorer

      3. Are we ready to vote, ratify and enact hf ga on preprod? (first next possible enactment date is 31st May if its voted for until 26th May (today) - epoch boundary on PreProd)

   2. Mainnet

      1. Set the new mainnet hard fork initiation governance action submission date - 3rd June, 8th June, 13th June, 18th June

5. Plutus Cost Model - Kevin, Ryan, Bosko

   1. Mainnet - submission postponed for this week, will be submitted today

      1. mincommittee size parameter update governance action expected to be submitted this week

6. van Rossem comms - Ian / Larisa

   1. Comms plan - CF, Midnight, Shielded, Emurgo, Intersect, IO

      1. Weekly comms meeting

   2. Comms in the last week - anything we missed

   3. Comms in the week ahead

7. Risk log

8. AOB

Key materials

• Summary

  • DBSync issue from 20th May, with inflated values being written to epoch.out_sum and epoch.fees at the first epoch boundary following a restart, rollback, cache miss, or upgrade, have been addressed - blog available here

    • There is a new version of DBSync, 13.7.1.0, that solves it properly without the workaround needed

    • Its recommended to upgrade to 13.7.1.0

      • If you are running 13.7.0.5, that version is also van Rossem compatible, and it just needs migration script executed as described in the release notes

  • Ogmios PR hasnt been raised yet, and having in mind its considered to be the critial tool, hard fork working group didnt recommend ratification and subsequently enactment of the hard fork initiation governance action on Cardano PreProd testnet. However, hard fork working group also discussed few different paths ahead with most prominent ones to be

    • Wait for Ogmios author to review PR changes

      • ideally to happen this week but

      • more likely to happen mid June given time availability

    • Fork Ogmios, make it useful in the van Rossem context, and give Ogmios author some time to assess changes from his perspective and merge the into the original code potentially

  • The decision will be made before or during the next hard fork working group meeting on Thursday, 28th May

  • Should there be a viable Ogmios PR in sight on the next meeting, hard fork working group will consider recommending ratifying hard fork on PreProd and also sticking to the original plan and submission of the hard fork initiation governance action on mainnet this week, 29th May

  • That also means that the submission of the hard fork initiation governance action on mainnet would happen few days earlier than the van Rossem hard fork enactment on PreProd

  • Risk log is to be updated:

    • With the latest findings on Ogmios readiness

    • With the DBSync issue from 20th May as accepted risk

    • With the casing on the plutus built-ins

  • Plutus Cost model parameter update governance action is expected to be submitted on mainnet later today, 26th May

  • Hard Fork working group will continue to assess van Rossem upgrade readiness every day, in and out of the scheduled working group meetings

• Hard Fork Working Group communication channels

  • Discord — #wg-hard-fork

  • Weekly bulletins

  • Luma calendar

• van Rossem Upgrade Update

• van Rossem readiness tracker

Action items and next steps

• Jeff/Sam: Assess Ogmios PR readiness and update the hard fork working group before the next meeting on THursday, 28th May

• Bosko: Risk log is to be updated:

  • With the latest findings on Ogmios readiness

  • With the DBSync issue from 20th May as accepted risk

  • With the casing on the plutus built-ins

• Bosko: The readiness tracker should be updated with the certain thresholds for nodes running latest stable version 11.0.1 (50%), top 20 dapps, top 20 exchanges by liquidity, etc. That would also bring additional confidence layer for a decision to submit hard fork initiation governance action on mainnet

• Ian: Publish the X post on newest DBSync version, 13.7.1.0

• Ryan: Submits Plutus Cost Models parameter update governance action on mainnet today, 26th May

• Ryan/Elena: Prepare for the potential hard fork initiation governance action on mainnet, this Friday, 29th May