Dev server#

Rspack CLI comes with a built-in @rspack/dev-server for development and debugging. Its capabilities are similar to webpack-dev-server, including features like hot module replacement (HMR), proxy server and more.

HMR#

By default, Rspack enables HMR in dev mode. You can disable HMR by configuring the devServer.hot option in Rspack configuration.

export default {
  devServer: {
    hot: false,
  },
};

Proxy#

Rspack has a built-in simple proxy server. You can enable the proxy server by configuring the devServer.proxy option in Rspack configuration. The devServer internally uses http-proxy-middleware to implement the proxy function. For example, you can proxy /api to http://localhost:3000 as follows:

export default {
  devServer: {
    proxy: [
      {
        context: ['/api'],
        target: 'http://localhost:3000',
        changeOrigin: true,
      },
    ],
  },
};

For more devServer configuration options, please refer to devServer.