astro/.changeset/two-geese-eat.md

astro
major

Remove buildConfig option parameter from integration astro:build:start hook in favour of the build.config option in the astro:config:setup hook.

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