Sei is a Layer 1 blockchain built with Cosmos SDK, purpose-designed for trading applications. It launched mainnet in August 2023 with the claim of being ‘the fastest Layer 1’ — featuring 400ms block finality, an on-chain central limit order book (CLOB) built at the protocol level, and a twin-turbo consensus mechanism combining optimistic parallelisation with intelligent block propagation. The native CLOB allows decentralised exchanges on Sei to offer a CEX-like order matching experience without building their own complex infrastructure. Sei v2 (2024) introduced full EVM compatibility, making Sei the first blockchain to run both Cosmos-native and EVM smart contracts simultaneously — meaning Ethereum developers can deploy unchanged Solidity code on Sei and benefit from its speed advantages. SEI is the native token for gas fees, staking, and governance. Sei v2 attracted significant DeFi migration from other EVM chains, particularly DEXes and perps protocols. Sei’s parallelised EVM (Ethereum Virtual Machine) executes non-conflicting transactions simultaneously, improving throughput significantly over sequential EVM execution. The Sei ecosystem includes DEXes, NFT marketplaces, and DeFi protocols leveraging the native CLOB. It competes with Solana for the ‘fastest execution chain’ positioning.
Example: A DEX builder on Ethereum is frustrated by slow transaction finality causing poor trading UX. They redeploy their Solidity contracts to Sei v2 without code changes. Trades now confirm in 400ms vs 12 seconds on Ethereum, and they can use Sei’s native order book to support limit orders natively. Their traders experience something closer to a CEX than any Ethereum DEX can offer.
Learn more: Sei Network
