Cardano Dijkstra Separates Linear Leios and Peras Into Two Phases

Cardano’s Dijkstra upgrade will not activate every planned consensus change at once. Phase 1 introduces a new ledger era,

Protocol Version 12, with Linear Leios and a broader set of ledger changes, while Peras is planned for a later activation within the same era.

Intersect currently targets Phase 1 code completion for Q4 2026, with Peras targeted for Q2 2027. Those dates are development estimates rather than confirmed mainnet hard-fork dates.

Linear Leios Enters Dijkstra First

Linear Leios is the main scaling component of Phase 1 and represents a simplified implementation of the broader Ouroboros Leios design.

Existing Praos blocks are extended into Ranking Blocks, while Endorser Blocks provide additional capacity for transaction processing. A stake-based committee certifies an Endorser Block before its certificate is included in a later Ranking Block and the associated transactions are applied to the ledger.

The Linear design removes Input Blocks and the broader model of concurrent Endorser Block production included in fuller Leios designs.

Intersect selected this approach to move part of the Leios architecture toward production without introducing the additional transaction-structure complexity required by the broader design. Its documentation also notes that some alternative approaches created dApp user-experience concerns that were considered unsuitable for the first deployment.

Dijkstra Phase 1 includes additional ledger changes such as Nested Transactions, Guard Scripts, Plutus V4 Script Context and a new block-body serialization structure. Together, they form the wider transition to the new ledger era.

No single TPS figure has been defined as the Dijkstra mainnet target. Linear Leios can operate under different configurations depending on transaction size and protocol parameters, with capacity expected to increase progressively after activation rather than launching immediately at a theoretical maximum.

Peras Is Prepared Without Another Ledger Era

Peras will not be activated in Phase 1, but part of the infrastructure it requires will already be introduced.

Dijkstra includes the codec extensions and protocol parameters from CIP-140 needed for a later Peras activation through a protocol version change within the existing era. Structural changes can therefore be completed during Phase 1 without forcing Cardano through another full ledger transition when Peras is ready.

The protocols also address different areas of network performance. Linear Leios expands transaction-processing capacity, while Peras adds a voting layer on top of Ouroboros Praos designed to accelerate settlement and increase confidence in the canonical chain sooner.

Phase 2 is therefore a separate consensus upgrade rather than an unfinished part of the Leios deployment. It can move through its own testing and ratification process after the required ledger foundations are already in place.

Code Completion Does Not Mean Dijkstra Mainnet

The current Q4 2026 target refers to Phase 1 code completion, not a guaranteed mainnet activation date.

After a Dijkstra-compatible node release, the upgrade must move through Preview and Preprod hard forks, stake pool operator testing and network-readiness checks. A Mainnet Hard Fork Initiation governance action can follow only after those stages are completed.

Linear Leios is also being tested through the Musashi Dojo environment, where node synchronization, Endorser Block certification and transaction flow have already been demonstrated. That work is being used to refine the parameters that will later determine production behavior.

Dijkstra also requires a targeted amendment to the Cardano Constitution. New protocol parameters need corresponding constitutional guardrails so governance can modify them within defined ranges after activation.

The proposed amendment is technical in scope and does not change existing governance roles or voting thresholds. The current target is to submit the combined amendment by epoch 655, beginning September 11, 2026, followed by DRep ratification and a constitutionality review by the Constitutional Committee.

That sequence leaves a deliberate gap between engineering completion and network activation. Dijkstra can establish the ledger changes required for Linear Leios first, while the groundwork already embedded in Phase 1 allows Peras to follow later as a separate protocol decision rather than another full ledger-era transition.