IntersectMBO Publishes Hard Fork Compatible Ogmios and Kupo Releases for Cardano van Rossem PreProd Upgrade

IntersectMBO has published hard fork compatible releases of Ogmios and Kupo, two important infrastructure tools in the Cardano developer ecosystem. Ogmios v6.14.0.1 and Kupo v2.11.0.1 are compatible with cardano-node 11.0.1 and protocol version 11, the protocol version associated with the van Rossem upgrade.

The releases follow an updated PreProd hard fork schedule after the hard fork initiation action was not ratified at the May 31 epoch boundary. According to IntersectMBO, the PreProd van Rossem hard fork initiation action is now expected to be ratified on June 5, 2026, with enactment expected on June 10, 2026, subject to successful on-chain governance ratification.

Cardano Developer Tools Receive van Rossem Compatible Releases

Ogmios and Kupo are not consumer-facing applications, but they sit inside the infrastructure layer used by Cardano developers, indexers, dApps and service providers. Ogmios acts as a lightweight WebSocket JSON-RPC bridge in front of a Cardano node, allowing applications to access chain sync, local state query, transaction submission and other node functions through a simpler interface.

Kupo is a lightweight Cardano chain indexer. It follows the chain, builds a database of UTxOs, datums, scripts and address patterns based on user-defined rules, and exposes that data through an HTTP API for faster lookups. For dApps, analytics tools and services that depend on reliable access to on-chain data, Kupo compatibility matters before a hard fork reaches a broader testing stage.

IntersectMBO published both releases under its own GitHub organization as an interim measure. This allows the PreProd hard fork process to continue while the original maintainers review the changes and prepare them for potential merge back into the canonical repositories before mainnet enactment.

Cardano PreProd Timeline Targets June 5 Ratification and June 10 Enactment

PreProd plays an important role because it gives the Cardano ecosystem a longer-running test environment that is closer to mainnet conditions. In that environment, testing is not limited to the Cardano node itself. Wallets, indexers, dApps, stake pool operators, service providers and infrastructure teams also need time to confirm that their systems remain compatible after the protocol update.

The earlier schedule targeted PreProd enactment on June 5. After the hard fork initiation action did not reach ratification at the May 31 epoch boundary, IntersectMBO updated the expected timeline. The new target is ratification on June 5 and enactment on June 10.

The updated timeline reflects Cardano’s hard fork process, where protocol changes move through on-chain ratification before enactment. DReps, SPOs and the Constitutional Committee are part of that process, which makes the wording around the dates important. IntersectMBO’s latest communication points to June 5 and June 10 as expected dates, tied to successful governance ratification.

Why Ogmios and Kupo Matter for the van Rossem Upgrade

Van Rossem is an intra-era hard fork within the Conway ledger era and moves Cardano to protocol version 11. The upgrade includes changes related to Plutus, ledger rules, node behavior and network operations, making compatibility across the surrounding tooling layer essential before broader deployment.

For Ogmios and Kupo, the relevant technical work focuses on low-level compatibility with cardano-node 11.0.1, including ledger API changes, encoder migrations, dependency updates and query behavior. These are not frontend changes for end users, but they are important for the applications and services that read, index and submit data through the Cardano node stack.

The interim releases address a practical coordination issue inside the Cardano infrastructure layer. PreProd testing depends on more than node readiness, because applications also need the tools that read, index and submit data against the new protocol version. With Ogmios and Kupo now available in hard fork compatible form, Cardano teams have concrete versions to test before the expected June 10 enactment, while IntersectMBO keeps the path open for the changes to return to the original repositories before mainnet.