Dijkstra hard fork Phase 1 (Ouroboros Linear Leios)

Cardano plans to roll out Phase 1 of its Dijkstra era, which introduces the Dijkstra ledger era and activates Ouroboros Linear Leios, with a tentative target of the fourth quarter of 2026. The upgrade concerns ADA holders and the broader Cardano ecosystem.

What is happening

The Dijkstra era is designed to deliver Cardano's next major protocol upgrade in two phases. Phase 1 brings in the Dijkstra ledger era and ships Ouroboros Linear Leios as a fully activated feature, targeted for Q4 2026. A later Phase 2 would activate Ouroboros Peras through an intra-era hard fork. As of the "Today" date in this card, this event has not yet occurred and remains ahead.

According to reporting, progress toward Dijkstra and Leios depends partly on governance processes. The Update Constitutional Committee 2026 governance action, managed through Intersect, needed to pass a voting threshold by a deadline on September 1. DReps were reported close to their 67% threshold, at 66.3%, while SPOs lagged further behind, at 39% against a 51% threshold, with urgency highlighted around the risk of missing the deadline.

The article notes that if this governance action does not pass, the constitutional committee's membership could fall below the required minimum of five members. Until the committee is restored to that minimum size, several categories of governance actions - including Hard Fork Initiation - cannot be ratified, which could directly affect the path toward Dijkstra and Leios, since those upgrades require both constitutional and technical changes.

Why it matters

Ouroboros Linear Leios is positioned as a core part of Cardano's next major protocol upgrade, and its activation would mark a significant technical milestone for the network's throughput and architecture. For ADA holders and traders, the outcome of related governance votes is relevant because a failure to maintain a functioning constitutional committee could delay or complicate the hard fork timeline.

Because the status of this event is tentative, the Q4 2026 target date is not confirmed and could shift depending on how governance processes, including committee composition and voting participation, play out. Market participants tracking Cardano's development roadmap should watch for updates on governance outcomes as an indicator of whether the Dijkstra timeline remains on track.

Key details

• Date: Q4 2026 (tentative, exact timing not confirmed)
• Project: Cardano
• Coins: ADA
• Category: Network Upgrade
• Status: Tentative
• Source: u.today