Cardano Dijkstra targets 2026 Leios, 2027 Peras rollout

Cardano's Dijkstra upgrade remains on its agreed technical scope and schedule, with developers targeting Linear Leios and Nested Transactions in the first phase before a separate Peras activation in 2027.

Summary

• Cardano's Dijkstra Phase 1 targets mainnet by year-end with Linear Leios and Nested Transactions included.
• Peras activation is planned for Q2 2027 through a separate intra-era hard fork on mainnet.
• Amaru currently validates and syncs to tip, with mainnet block production targeted for November 2026.
• Cardano plans one constitutional amendment adding Dijkstra parameters, targeted for submission by September 11, 2026.
• Dijkstra's first phase also prepares Peras codecs and parameters before the protocol activates next year.

Intersect said in its Aug. 14 update that planning is now shifting toward ecosystem readiness, testnet reporting and support for alternative node implementations.

The latest official roadmap divides Dijkstra into two phases. Phase 1 introduces the new Dijkstra ledger era and Linear Leios, with a Q4 2026 code-completion target. Phase 2 activates Ouroboros Peras through an intra-era hard fork targeted for Q2 2027. The published schedule explicitly says those dates are estimates and "not guarantees," as testing and on-chain governance can extend the final mainnet timeline.

Cardano Dijkstra puts Linear Leios in Phase 1

Linear Leios is the main scaling component of the first Dijkstra hard fork. Rather than replacing Cardano's Praos security model, it introduces Endorser Blocks that can reference additional transactions and have them certified by stake-based committees. The design aims to increase throughput while retaining the existing base consensus guarantees.

Phase 1 also includes Nested Transactions, new transaction and block serialization structures, PlutusV4 changes and several protocol parameter additions. Importantly, it will install the codec extensions and parameters required for Peras without activating Peras itself.

As crypto.news previously reported, Cardano's van Rossem hard fork moved mainnet to Protocol Version 11 in July and laid technical groundwork for Dijkstra and Leios.

Ouroboros Peras is scheduled for Phase 2. The protocol adds a voting layer that allows committees of stake pool operators to vote on recent chain tips, giving Cardano a way to reach settlement faster than under standard Praos chain-depth rules.

Intersect currently targets Q2 2027 for the Peras phase. That will require its own Preview and Pre-production deployments followed by another mainnet governance action. Phase 1 must already be active because it supplies the ledger structures and protocol parameters Peras requires.

Amaru moves toward Cardano block production

Dijkstra is also pushing Cardano toward greater node-client diversity. Intersect said Amaru, an open-source Rust implementation, is already relay capable and can validate and synchronize with the chain tip. Mainnet block production is targeted for November 2026.

Amaru's own development tracker provides more detail. Its general block-producer release is targeted for Sept. 30, followed by a Dijkstra-compatible block producer milestone on Oct. 29 and a Leios-compatible release on Nov. 26. These are development milestones rather than guaranteed Cardano mainnet activation dates.

Node diversity would reduce Cardano's reliance on its Haskell implementation. Intersect is also developing a Dijkstra readiness tracker covering testnet performance and ecosystem preparation while inviting alternative node teams into its weekly Hard Fork Working Group.

Governance changes must arrive before Dijkstra

Dijkstra introduces protocol parameters that Cardano governance cannot change unless they appear explicitly within the Constitution's guardrails. Input Output therefore plans a narrow constitutional amendment adding the relevant parameters and permitted ranges. It does not propose changes to governance roles, voting thresholds or constitutional principles.

The current target is to submit that governance action no later than Epoch 655, beginning Sept. 11. Community discussion is already being organized through Intersect's Constitutional Amendment Portal, which had received four initial submissions by Aug. 14.

Ultimately, the near-term work centers on completing Dijkstra code, establishing readiness criteria and moving the first phase through Preview and Pre-production before any mainnet governance vote. Intersect's latest update says the agreed scope and target dates remain unchanged.

The main caveat is timing. Although the Haskell node team is working toward Phase 1 mainnet delivery by the end of 2026, the formal roadmap describes Q4 as a code-completion target and says governance and community testing can push activation later. Peras remains targeted for Q2 2027 after Phase 1 is deployed.