Cardano Cuts IO Out of the Loop as Van Rossem Hard Fork Hands the Reins to ADA Voters 🗳️

Cardano activated its Van Rossem hard fork on July 18 at 21:44 UTC, moving the mainnet from protocol version 10 to version 11 and lowering smart contract execution costs in the process. Onchain data from Cardanoscan shows the network exited version 10 in epoch 643 and adopted version 11 in epoch 644, with the upgrade ratified on July 13 after going through three separate governance bodies.

The upgrade is the first in Cardano's history proposed, debated and enacted entirely through its onchain Voltaire-era governance system rather than by Input Output, the engineering firm that designed and built the blockchain. "As well as Plutus improvements and Plutus Cost Model enhancements, this upgrade lays the foundation for the next upgrade, the Dijkstra era hard fork, which will introduce Ouroboros Leios to Cardano," Input Output wrote in a weekly development report on Friday.

Governance tallies underscore how the new process played out: delegated representatives backed the fork 78.97% in favor against a 60% threshold, while the seven-member constitutional committee unanimously deemed it compliant with the Cardano Constitution, where only five votes were required. All previous Cardano hard forks were coordinated top-down by founding entities, chiefly Input Output, making Van Rossem the first community-driven upgrade on record.

The technical changes embedded in version 11 adjust the Plutus cost model, allowing $ADA smart contracts to be executed more cheaply and paving the way for more capable decentralized applications on Cardano. Developers have framed the fork as procedural and technical groundwork for the Dijkstra-era hard fork, which will introduce Ouroboros Leios, a scaling proposal for the Ouroboros proof-of-stake consensus expected to launch in late 2026.

Ouroboros Leios is designed to substantially raise Cardano's transactions per second without weakening the security guarantees of the existing consensus mechanism. The Cardano Foundation separately announced it has canceled its annual conference following a failed funding vote, a development unrelated to the Van Rossem activation.