Welcome to the Musashi Dojo
Why Leios?
Block space is the resource a blockchain offers its users, and its supply is fixed: so many bytes per block, so many smart contract execution units per block, so many blocks per unit of time. Demand keeps its own schedule. Most of the time it runs stable and well below the limit; then a launch, an airdrop, or a market move compresses it into a spike. It is the textbook problem of seasonal demand against fixed capacity, with one twist: on a chain the season can arrive in minutes. Applications already plan around the limit. The Midnight Glacier Drop spread its redemption over months rather than risk a poor user experience due to a congested network. Each redemption required a Cardano Mainnet transaction.
The squeeze sharpens as Cardano's activity consolidates in decentralized finance (DeFi), where timeliness is the difference between the trade you wanted and the trade you got: prices move, windows close, liquidations fire. Some chains meet a burst by selling the front of the queue: pay more, land sooner. Cardano has no such lane. Differential pricing is under active research, and today every transaction waits in the same line, regardless of who sent it. So the line itself has to move faster. Every chain has a throughput ceiling; an app can only promise its users what the chain can deliver, and in DeFi the promise has a deadline.
Ouroboros Leios is Cardano's answer to that ceiling. It runs in a dormant state as an overlay on Ouroboros Praos, the protocol Cardano uses today. When transactions arrive faster than Praos alone can clear, Leios steps in and, in the gaps between Praos blocks, builds a second kind of block: the endorser block, which carries far more transactions and validates them in parallel. Once enough of the stake has validated them, a later Praos block carries a small certificate for the endorser block, and the whole batch lands on the chain at once. Security stays where it always was, with Praos. Capacity arrives when demand asks for it.
Today we are launching MusashiNet, the public testnet that takes the Leios prototype all the way to production-grade code on Cardano mainnet.
It takes its name from Miyamoto Musashi, a samurai who fought close to sixty duels and retired undefeated. Every fencing school of his era taught one sword style; Musashi used two, a long one and a short one, which let him attack and defend at once and adapt to conditions a single blade could not cover. A chain running Leios fights the same way: the short sword is the Praos block, the long sword is the endorser block.
MusashiNet is the Dojo, the training hall where Leios is perfected. Musashi's Book of Five Rings also gave the testnet its five phases, each built on the one before. Earth, Water, Fire, Wind, Void.
Join the Dojo
Earth begins today. The first phase has a single goal: to validate the Linear Leios design of CIP-164 in the wild — the whole protocol running end to end, Praos blocks produced, endorser blocks announced, the stake voting on them, certificates landing on chain, at real latencies and across real distance.
If you run a stake pool, Leios needs you sparring, not spectating. The sharpest questions left can only be answered from hardware we do not own, in places we did not choose. Spin up a node on MusashiNet, register your pool, and put the protocol through your conditions before it reaches mainnet. Come train with us.