Configuration

Ness uses one framework configuration file: ness.config.mjs. It contains Vite integrations, React Router options, the production server, and instrumentation hooks.

ness.config.mjs

import { defineNessConfig } from '@nessframework/router';
import { ness } from '@nessframework/router/vite';
import nest from '@nessframework/nest';
import { nestServer } from '@nessframework/nest/server';
import security from '@nessframework/security';

const rsc = process.env.NESS_EXPERIMENTAL_RSC === 'true';

export default defineNessConfig({
  vite: {
    plugins: [ness({ rsc, plugins: [nest(), security()] })],
  },
  router: {
    rsc,
    ssr: true,
    prerender: ['/', '/about'],
    allowedActionOrigins: ['app.example.com'],
  },
  server: {
    configureServer: nestServer({ prefix: 'api' }),
    redirects: [
      { source: '/old/:slug', destination: '/blog/:slug', permanent: true },
    ],
    headers: [
      {
        source: '/api/*',
        headers: [{ key: 'cache-control', value: 'no-store' }],
      },
    ],
    images: {
      remotePatterns: [{ protocol: 'https', hostname: 'images.example.com' }],
    },
  },
  instrumentation: {
    async register() {
      // Initialize tracing, metrics, or error reporting.
    },
    onError({ error }) {
      console.error(error);
    },
  },
});

Vite

The vite section accepts standard Vite configuration. Official NestJS, Tailwind, security, environment, compression, and analyzer integrations are composed through ness({ plugins }). Only VITE_ and NESS_PUBLIC_ variables are exposed to browser code.

Router

The router section accepts React Router Framework Mode options. Ness supplies ESM server bundles, route-module splitting, subresource integrity, lazy route discovery, streaming SSR, and the build/ directory by default.

Production server

The server section is loaded by ness start. It supports the NestJS bridge, redirects, rewrites, response headers, image policy, middleware, and cache adapters.

Instrumentation

The instrumentation section receives application lifecycle and error hooks without requiring another root file.

The CLI generates React Router's compatibility adapter under .ness/config; it is build output and must not be committed. TypeScript applications still keep tsconfig.json, and Docker deployments keep Dockerfile, because those files are read directly by their respective external tools.