Cardano launches van Rossem hard fork: the first governance-driven upgrade in history.

Cardano's mainnet officially launched the van Rossem hard fork on Saturday, upgrading the protocol version from 10 to 11, bringing infrastructure for reduced smart contract costs and subsequent expansion kit upgrades to the network.

According to Cardanoscan's on-chain data, the network was still Protocol Version 10 at the end of epoch 643, and officially switched to Version 11 after entering epoch 644.

More than just price reductions: Plutus improvements and updated cost models

This upgrade encompasses performance improvements to the Plutus smart contract platform and enhancements to the Plutus cost model. Input Output (IO) noted in its weekly development report that these updates lay the technical foundation for the next phase of the Dijkstra era hard fork.

For developers, the updated Plutus cost model means that smart contract gas fees will more accurately reflect actual computation costs, helping to reduce the cost burden of daily transactions.

A first in history: a hard fork driven by community governance

Unlike previous upgrades coordinated by Input Output engineers, this van Rossem upgrade is the first hard fork in Cardano history driven by community governance. This marks a further maturation of Cardano's decentralized governance mechanism.

In the past, several hard forks (such as Vasil, Alonzo, and Chang) were all coordinated and deployed uniformly by Input Output on the developer side. Van Rossem, however, uses the Cardano governance proposal process, where ADA holders vote to determine the timing and triggers of the upgrade.

Ouroboros Leios: Massive Expansion Kit Solution Before Year-End

Ouroboros Leios is an extension suite proposal for the Ouroboros Proof-of-Stake consensus mechanism used by Cardano, and is expected to launch by the end of 2026. Its core objective is to significantly increase the number of transactions per second (TPS) without compromising security guarantees.

The Input Output report states: "In addition to Plutus improvements and enhancements to the Plutus cost model, this upgrade paves the way for the next phase of the Dijkstra era hard fork, which will bring Ouroboros Leios to Cardano."

If the Leios scaling solution is implemented as scheduled, Cardano's theoretical throughput is expected to increase from the current tens of transactions per second to hundreds or even thousands, narrowing the gap with competitors such as Ethereum and Solana in terms of scaling capabilities.

From van Rossem to Dijkstra: Cardano Upgrade Roadmap

The van Rossem hard fork is just the first step in Cardano's upgrade roadmap for the second half of 2026. According to IO's development roadmap, the Dijkstra-era hard fork will follow immediately, and is expected to bring:

• Ouroboros Leios officially launched, enabling on-chain scaling tools.
• Further reduction in smart contract execution costs
• Continuous verification and improvement of governance mechanisms

For investors holding ADA, the successful launch of van Rossem is not only a technological milestone, but also a validation of the Cardano community governance system's ability to effectively coordinate network-level upgrades.