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Build on Sei

@sei-js is the complete TypeScript SDK for building applications on Sei Network. Whether you’re creating DeFi protocols, NFT marketplaces, or blockchain games, @sei-js provides everything you need to ship faster.

Works with your favorite tools: Sei is fully EVM-compatible, so you can use Viem, Ethers.js, Foundry, Hardhat, and all your existing Ethereum development tools without any changes. @sei-js extends these tools with Sei-specific features like precompiled contracts and optimized wallet connections.

Quick Start

Build your first Sei app in under 10 minutes

Contributing

Help improve @sei-js and contribute to the project

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Why @sei-js?

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Package ecosystem

@sei-js/precompiles

Native blockchain function access

Access Sei’s precompiled contracts directly from your EVM applications.

yarn add @sei-js/precompiles

@sei-js/create-sei

Project scaffolding and templates

Bootstrap new Sei projects with pre-configured templates and tooling.

npx @sei-js/create-sei app

@sei-js/sei-global-wallet

Universal wallet connections

Connect to any Sei-compatible wallet using the EIP-6963 standard.

yarn add @sei-js/sei-global-wallet

@sei-js/ledger

Hardware wallet integration

Secure transaction signing with Ledger hardware wallets.

yarn add @sei-js/ledger

@sei-js/mcp-server

LLM blockchain integration

Teach Claude, ChatGPT, or any LLM to interact with the Sei blockchain.

npm install -g @sei-js/mcp-server

🤖 Teach Your LLM About Sei

Connect Claude, ChatGPT, or any LLM to the Sei blockchain with @sei-js/mcp-server. Your AI assistant can check balances, transfer tokens, deploy contracts, and guide users through the entire @sei-js ecosystem.

Get Started with MCP →

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Community & Support

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Report Issues

  • GitHub Issues - Report bugs and request features
  • Include reproduction steps and environment details
  • Check existing issues before creating new ones