next.config.js

/**
 * Next.js config for the zkCoins explorer.
 *
 * Static export only: no server runtime, no server state, no keys.
 * The node/API base URL is required at build time — there is no default host.
 */

const baseUrl = process.env.NEXT_PUBLIC_NODE_BASE_URL;
if (typeof baseUrl !== 'string' || baseUrl.length === 0) {
  throw new Error(
    'NEXT_PUBLIC_NODE_BASE_URL is required at build time (no default). ' +
      'Set it to the node/API origin the explorer should read, e.g. https://node.example.com',
  );
}
let parsedBaseUrl;
try {
  parsedBaseUrl = new URL(baseUrl);
} catch {
  throw new Error(
    `NEXT_PUBLIC_NODE_BASE_URL is not a valid absolute URL, got ${JSON.stringify(baseUrl)}`,
  );
}
if (parsedBaseUrl.protocol !== 'http:' && parsedBaseUrl.protocol !== 'https:') {
  throw new Error(
    `NEXT_PUBLIC_NODE_BASE_URL must use http or https protocol, got ${JSON.stringify(baseUrl)}`,
  );
}
// WHATWG rejects empty hosts on http(s) before this check can run.
/* v8 ignore next -- empty http(s) host is a parse failure, not a parsed empty hostname */
if (!parsedBaseUrl.hostname) {
  throw new Error(
    `NEXT_PUBLIC_NODE_BASE_URL hostname must be non-empty, got ${JSON.stringify(baseUrl)}`,
  );
}
if (parsedBaseUrl.username || parsedBaseUrl.password) {
  throw new Error(
    `NEXT_PUBLIC_NODE_BASE_URL must not include userinfo credentials, got ${JSON.stringify(baseUrl)}`,
  );
}
if (parsedBaseUrl.search) {
  throw new Error(
    `NEXT_PUBLIC_NODE_BASE_URL must not include a query string, got ${JSON.stringify(baseUrl)}`,
  );
}
if (parsedBaseUrl.hash) {
  throw new Error(
    `NEXT_PUBLIC_NODE_BASE_URL must not include a fragment, got ${JSON.stringify(baseUrl)}`,
  );
}

/** @type {import('next').NextConfig} */
const nextConfig = {
  // Stateless, self-hostable container: pure static assets + client hydration.
  // Static export does not support next.config headers(); Referrer-Policy is
  // set via <meta name="referrer" content="no-referrer"> in the root layout
  // (spec §5.6 defense-in-depth for bearer fragment secrets).
  output: 'export',
  images: {
    unoptimized: true,
  },
  trailingSlash: true,
  // Local monorepo SDK (file:../sdk) is ESM and must be transpiled by Next.
  transpilePackages: ['@zkcoins/sdk'],
};

module.exports = nextConfig;