Consensus
Delivering sustainable throughput capacity at the consensus layer. Ships Leios.
The team behind the initiative
The opportunity
The 2030 Vision sets a clear target: Cardano must scale from today's approximately 800,000 transactions per month to over 27 million, while remaining economically self-sufficient as the Reserve diminishes. The consensus layer is where that capacity is delivered, and Leios is the mechanism purpose-built to get there.
Leios enhances Ouroboros Praos rather than replacing it, preserving Cardano's security guarantees while dramatically improving performance. It introduces Endorser Blocks and committee-based validation to deliver a 10 to 65x throughput increase, directly aligned with the 2030 adoption targets, without compromising decentralization or making stake pool operations economically unviable.
This is not about chasing theoretical maximums. It is about building the capacity Cardano needs to become the trusted foundation for DeFi, real-world assets, and enterprise adoption, ensuring the network can generate sufficient fee revenue to thrive independently.
The Initiative
Consensus
This is the largest technical initiative in the portfolio.
It continues Leios development from the current budget cycle, which concludes in June 2026 with an Early Public Testnet milestone. During the current cycle, CIP-164 was merged, initial throughput was demonstrated on an alpha feature-complete implementation, and Leios was deployed on a dedicated public testnet.
The 2026/27 cycle focuses on maturing Leios from prototype to mainnet-ready, progressing through Software Readiness Levels 5 to 8. Three objectives structure the work:
- Release Candidate: The critical path. Maturing the implementation to a mainnet-ready release candidate through substantial engineering effort, conformance testing against formal specifications, and progression through SRL 5 to 8. This includes a substantial rewrite of consensus components, implementing Leios block structure for the Dijkstra ledger era, completing the conformance test suite against the Agda formal specification, and integration into the primary node implementation.
- High Confidence: Systematic validation of the protocol through parameter exploration, continuous load testing, and adversarial testing on the public testnet. This includes studying timing parameters and size limits, developing a parameter graduation plan, stake-based and network-based attack testing, red-teaming exercises, and culminating in an updated threat model with validated mitigations.
- Hard-fork Enabling Leios: Everything within IO's control to make the hard fork possible: stable client interfaces, implementation-independent technical documentation, SPO and developer workshops, tactical support for close-by projects (DB-Sync, Mithril, Blockfrost), testnet hard-forks, mainnet parameter graduation plan, contingency procedures, and preparation of updated guardrails script and rationale documents for governance. Success is defined by completing these activities, not by the mainnet hard fork occurring.
Treasury ask: ₳27,714,342
Who is building
This initiative is led by Carlos Lopez De Lara and Sebastian Nagel at Input Output (IO), delivered by IO engineering teams spanning consensus, ledger, networking, cryptography, node/API development, performance and tracing, testing, research, and formal methods.
Expected outcomes
- Leios implementation matured from early testnet prototype to a mainnet-ready release candidate, progressing through Software Readiness Levels 5 to 8.
- Protocol validated through systematic parameter exploration, continuous load testing, and adversarial red-teaming, with an updated threat model and validated mitigations.
- Hard-fork enabling activities completed: stable client interfaces, technical documentation, SPO and developer workshops, testnet hard-forks, and governance artifact preparation.
- Cardano positioned to meet 2030 monthly transaction targets with a 10 to 65x throughput increase and headroom for sustained growth.
Ecosystem Impact
This is the highest-impact technical initiative in the entire portfolio. Leios directly advances Monthly Transactions (the 2030 target of 27 million monthly transactions is impossible without the capacity increase Leios provides), Reliability (preserving Praos safety and liveness guarantees), and Scalability (delivering a 10 to 65x capacity increase). It also enables downstream growth in TVL, MAU, and Revenue/Adoption by expanding the throughput capacity available to the entire network and enabling fee revenue growth necessary for long-term sustainability as the Reserve diminishes.
Governance links
Formal treasury proposal
The on-chain submission, read the full proposal text and rationale.
View the formal proposalJoin the Conversation
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