✨ Major Changes

• #5056 e55af8a23 Thanks @matthewp! - # Standalone mode for the Node.js adapter

  New in @astrojs/node is support for standalone mode. With standalone mode you can start your production server without needing to write any server JavaScript yourself. The server starts simply by running the script like so:

  node ./dist/server/entry.mjs

  To enable standalone mode, set the new mode to 'standalone' option in your Astro config:

  import { defineConfig } from 'astro/config';
  import nodejs from '@astrojs/node';
  
  export default defineConfig({
    output: 'server',
    adapter: nodejs({
      mode: 'standalone',
    }),
  });

  See the @astrojs/node documentation to learn all of the options available in standalone mode.

  This is a semver major change because the new mode option is required. Existing @astrojs/node users who are using their own HTTP server framework such as Express can upgrade by setting the mode option to 'middleware' in order to build to a middleware mode, which is the same behavior and API as before.

  import { defineConfig } from 'astro/config';
  import nodejs from '@astrojs/node';
  
  export default defineConfig({
    output: 'server',
    adapter: nodejs({
      mode: 'middleware',
    }),
  });

🍿 Minor Changes

• #5056 e55af8a23 Thanks @matthewp! - # Adapter support for astro preview

  Adapters are now about to support the astro preview command via a new integration option. The Node.js adapter @astrojs/node is the first of the built-in adapters to gain support for this. What this means is that if you are using @astrojs/node you can new preview your SSR app by running:

  npm run preview

  We will be updating the other first party Astro adapters to support preview over time. Adapters can opt in to this feature by providing the previewEntrypoint via the setAdapter function in astro:config:done hook. The Node.js adapter’s code looks like this:

  export default function() {
    return {
      name: '@astrojs/node',
      hooks: {
        'astro:config:done': ({ setAdapter, config }) => {
          setAdapter({
            name: '@astrojs/node',
            serverEntrypoint: '@astrojs/node/server.js',
            previewEntrypoint: '@astrojs/node/preview.js',
            exports: ['handler'],
          });
  
          // more here
        }
      }
    };
  }

  The previewEntrypoint is a module in the adapter’s package that is a Node.js script. This script is run when astro preview is run and is charged with starting up the built server. See the Node.js implementation in @astrojs/node to see how that is implemented.

• #5056 e55af8a23 Thanks @matthewp! - # New build configuration

  The ability to customize SSR build configuration more granularly is now available in Astro. You can now customize the output folder for server (the server code for SSR), client (your client-side JavaScript and assets), and serverEntry (the name of the entrypoint server module). Here are the defaults:

  import { defineConfig } from 'astro/config';
  
  export default defineConfig({
    output: 'server',
    build: {
      server: './dist/server/',
      client: './dist/client/',
      serverEntry: 'entry.mjs',
    },
  });

  These new configuration options are only supported in SSR mode and are ignored when building to SSG (a static site).

  The integration hook astro:build:start includes a param buildConfig which includes all of these same options. You can continue to use this param in Astro 1.x, but it is deprecated in favor of the new build.config options. All of the built-in adapters have been updated to the new format. If you have an integration that depends on this param we suggest upgrading to do this instead:

  export default function myIntegration() {
    return {
      name: 'my-integration',
      hooks: {
        'astro:config:setup': ({ updateConfig }) => {
          updateConfig({
            build: {
              server: '...',
            },
          });
        },
      },
    };
  }