Leios does not replace Ouroboros Praos, the consensus protocol Cardano has run since 2017. Instead, it layers two new components on top of it: Endorser Blocks, which carry larger transaction batches under favorable network conditions, and committee-based validation. Ranking Blocks continue to anchor the ordering of transactions, preserving transaction ordering integrity within the bifurcated architecture. When conditions degrade, the system reverts automatically to standard Praos behavior. The design is formalized in CIP-164, which has already been merged into the Cardano Improvement Proposal repository. In full deployment, IOG targets a peak throughput of more than 1,500 transactions per second, representing a 10 to 65 times improvement over Ouroboros Praos's current capacity.

Cardano blocks have been running at 80 to 90 percent capacity, creating persistent congestion during peak demand.

"We've designed Leios to enhance Praos, not replace it," said IOG product manager Carlos Lopez de Lara and software engineering lead Sebastian Nagel in the proposal. "It adds endorser blocks and committee-based validation, which increase the number of transactions Cardano can process while preserving Praos's security model." Chief Scientist Aggelos Kiayias framed the broader design philosophy in a separate IOG blog post on the Ouroboros architecture: "If the network shows high uptime and reliable connectivity, the protocol can accelerate to near centralized-like performance. When conditions degrade, whether through node failures, latency, or network splits, the protocol automatically falls back to a safe, decentralized mode."

IOG has also tied the upgrade to a longer-term strategic target. The company's 2030 product strategy sets a specific goal: scaling from roughly 800,000 transactions per month to over 27 million, a 30x increase, while staying economically self-sufficient as Reserve diminishes.

The rollout is structured in phases. The network would initially run at twice its current capacity, scaling toward 30 times, with each step validated on testnet before any mainnet parameter change is applied. IOG is targeting a public testnet launch for June 2026.

The on-chain governance vote to release the treasury funds is also scheduled for that month, following community advisory voting currently underway in May.

The governance threshold is not a formality. Cardano's Voltaire framework requires a 67 percent supermajority from Delegated Representatives, known as DReps, plus approval from five of seven Constitutional Committee members for any treasury withdrawal. This is the first major throughput infrastructure proposal to go through that process. IOG cannot proceed unilaterally. Of 69 total proposals submitted in this budget cycle, Intersect MBO has placed 39 on-chain governance actions for community vote, the Leios proposal among them. IOG has tried to address accountability concerns directly: all milestones will be independently verified, and any unspent ADA must be returned to the treasury. The company has already returned 4.1 million ADA from two cancelled projects, Acropolis and Tiered Pricing, earlier this year.

At current ADA prices of roughly $0.28 to $0.30, the ₳27.7 million ask translates to approximately $7.7 million to $8.3 million USD. IOG has positioned the ask as modest for a consensus-layer upgrade. It fits the company's broader posture for 2026: IOG's total treasury request across all proposals this year is $38.9 million to $46.8 million, roughly half of its $97.5 million ask the prior year.

The urgency behind Leios is not theoretical. In March 2026, the Midnight privacy sidechain launched with UK fintech Monument Bank tokenizing £250 million in customer deposits. In April 2026, the x402 Protocol for AI agents recorded $6.2 billion in day-one volume on Cardano. Both events increase pressure on Cardano's base layer throughput, and both illustrate why the current ceiling is a live operational constraint rather than a future hypothetical.

Leios is also the L1 prerequisite for a broader scaling ecosystem. IOG is developing Hydra, a state channel solution, and Midgard, an optimistic rollup system, as complementary L2 layers. IOG has stated that only with both L1 and L2 improvements in place does Cardano have a credible scaling story.

The Leios timeline intersects directly with where Cardano's real-world deployment is most concentrated. The 2026 Global Crypto Adoption Index places India at number one globally and Nigeria at number two. Ethiopia debuted at number ten, Kenya at number thirteen, and Ghana at number twenty. Sub-Saharan Africa now has four nations in the global top twenty, double its 2024 count. A separate $30 million Africa-focused developer grant program, approved through Cardano's treasury earlier this year, received 180 project submissions from 14 countries in its first week alone, covering digital identity, remittances, supply-chain transparency, and financial inclusion tools. In Ethiopia, the Atala PRISM program has deployed government-backed digital identity for students, one of the most concrete examples of Cardano's infrastructure role moving from pilot to production on the continent.

All of those applications face the same ceiling: Cardano's current throughput limits how many users any of them can practically serve. Leios is the infrastructure prerequisite for that activity to scale. The Leios roadmap also sets a minimum hardware requirement for stake pool operators at six or more CPU cores and 100 Mbps bandwidth, a deliberate decision to preserve participation for operators in lower-resource environments including growing SPO communities in Kenya, Nigeria, and South Africa.

For South Asian developers and users, the remittance angle is equally concrete. Pakistan ranked eighth globally in the 2026 Crypto Adoption Index, a stronger signal of regional adoption than any single use-case metric. India and Pakistan together represent two of the world's largest remittance recipient nations. Cross-border payment applications targeting the India-GCC, Pakistan-GCC, and Bangladesh-Middle East corridors require sustained throughput and low latency to compete with established fintech rails. Cardano has a smaller but growing footprint in South Asia compared to Africa, but with smart contract calls now accounting for roughly 35 percent of daily Cardano activity, DeFi and payments platforms across the region face the same block congestion constraints as all users.

The immediate precursor to Leios is the Van Rossem hard fork, Protocol Version 11, which entered testing on Cardano's Preview testnet with a target enactment date of May 21, 2026. It is Cardano's first governance-activated hard fork and will be the first test of Cardano's governance-activated upgrade process before Leios requires its own separate vote.

The public testnet launch and the governance vote on the treasury withdrawal are both expected in June. Mainnet deployment, if approved, is targeted for the end of the year.