Scaffold Sei

Create a Next.js dApp with wallet integration and Sei network configuration

@sei-js/create-sei creates a Next.js dApp with TypeScript, wallet integration, and Sei network configuration.

npx @sei-js/create-sei app -n my-sei-app

The generated project includes Wagmi, Viem, RainbowKit, TypeScript, Tailwind CSS, Mantine UI, and Biome. It pins @sei-js/precompiles 3.x.

Quick start

You do not need to install @sei-js/create-sei globally. -n and --name are the same option.

npx

npx @sei-js/create-sei app -n my-sei-app

bunx

bunx @sei-js/create-sei app -n my-sei-app

The project name must be an unscoped lowercase npm package name (my-sei-app). Scoped names, spaces, and most punctuation are rejected.

Interactive setup

1. Run the CLI

   Run the command without -n to enter the project name interactively:

   npx @sei-js/create-sei app
   
2. Install and run

   cd my-sei-app
   bun install
   bun run dev
   
3. Start building

   Open http://localhost:3000. The generated dApp connects to Pacific-1 when NEXT_PUBLIC_CHAIN is unset. Set NEXT_PUBLIC_CHAIN=testnet in .env.local to use Atlantic-2. The template’s .env.example already sets that value, so copying it to .env.local selects testnet.

CLI options

Command	Description
app	Create a new Sei dApp
app -n <name>	Specify a project name (--name is the same flag)
app --extension <ext>	Add an optional extension to your project
list-extensions	List available extensions

Default template

The default template is a Next.js EVM dApp. Wagmi and Viem provide typed blockchain interactions. RainbowKit provides wallet connections and defaults to the generic injected connector, not a MetaMask-only setup.

The template pins Next.js 15, React 19, Wagmi 2, Viem 2, RainbowKit 2, TanStack Query 5, Tailwind CSS 4, Mantine 8, Biome 2, and @sei-js/precompiles 3.x. Exact versions live in the generated package.json.

npx @sei-js/create-sei app -n my-sei-app

The template declares packageManager: bun@1.3.14, so use Bun 1.3.14 or newer for bun install and bun run dev. Its overrides block pins patched transitive dependencies in the npm and Bun format. Yarn reads resolutions and pnpm reads pnpm.overrides, so both skip those pins and resolve a different, unverified dependency graph.

WalletConnect-based wallets need NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID in .env.local. The injected connector works without it. Next.js image optimization is disabled in the template because of a Sharp version conflict, so next/image serves unoptimized images.

Extensions

Use an extension to add an example to the base template.

List available extensions

npx @sei-js/create-sei list-extensions

Precompiles extension

Add a Bank precompile example that queries the native SEI supply:

npx @sei-js/create-sei app -n my-sei-precompile-app --extension precompiles

Included configuration

• Next.js App Router project structure
• Wallet connections through Wagmi, RainbowKit, and the injected browser-wallet connector
• Pacific-1 and Atlantic-2 chain configuration via NEXT_PUBLIC_CHAIN
• TypeScript, Biome, Mantine UI, and Tailwind CSS

Install Node.js 20 or newer to run the CLI with npx. That is the version the generated project’s .nvmrc pins. Install Bun 1.3.14 or newer to install and run the generated project.

Troubleshooting

• If bun install fails, confirm bun --version reports 1.3.14 or newer.
• For Node.js version conflicts when running npx, use nvm to switch to Node 20 or newer.
• For npm permission errors, do not use sudo. Use nvm or fix your npm permissions.
• For registry timeouts, run npm config set registry https://registry.npmjs.org/ before retrying npx.