Documentation

Wrap your Next.js config in withConsentManifest. An existing config object or function goes in as the first argument, unchanged:

import { withConsentManifest } from 'c15t/next/build';
import type { NextConfig } from 'next';

const nextConfig = {} satisfies NextConfig;

// Reads NEXT_PUBLIC_C15T_BACKEND_URL, like defineConsentConfig.
export default withConsentManifest(nextConfig);

next build, next dev and next typegen fetch ${backendURL}/manifest and write the policy to node_modules/.cache/c15t/, outside your source tree, so there is nothing to keep out of Git. next start serves the built snapshot and fetches no policy. Without a backendURL option, the build reads the backendURL in c15t.config.ts, which defaults to NEXT_PUBLIC_C15T_BACKEND_URL, then NEXT_PUBLIC_INTH_PROJECT_URL, so saves and the snapshot point at the same project.

The wrapper reads c15t.config.ts the way Next.js reads next.config.ts, and skips the fetch for mode: hosted(), mode: offline(), manifest({ snapshot }) and manifest({ source: 'runtime' }), which read no build-time manifest. Those builds never contact the backend. If the file can't be read at build time, for example because it imports something Node can't load, the build warns and fetches as for manifest().

The wrapper also finds c15t.config.ts (or .mts, .js, .mjs) at the project root, next to next.config.ts, and points c15t/generated at the cache, in Turbopack and webpack. ConsentRoot, resolveConsent and the consent route read both without an import. Server code that needs the snapshot itself imports snapshot from c15t/generated. Only server bundles get the snapshot: in a browser bundle, c15t/generated imports server-only, so importing it from a client component fails the build. The wrapper also adds c15t, @c15t/core and @c15t/nextjs to transpilePackages, so Pages Router server bundles see the aliases. A package you list in serverExternalPackages stays external: it reads no c15t.config.ts and fetches the policy at runtime.

If the fetch fails, next build stops. next dev logs a warning instead, and snapshot is undefined, so the server fetches and caches the policy at runtime, as with runtime manifest caching. To let a build continue the same way, set onBuildError: 'runtime', or run it with C15T_ON_BUILD_ERROR=runtime:

export default withConsentManifest(nextConfig, { onBuildError: 'runtime' });

A missing backend URL counts as a failed fetch. The build skips the fetch and leaves snapshot undefined when the backend URL is relative, or when the config sets output: 'export', which has no server to use the snapshot. With onBuildError: 'fail', a relative URL stops the build. A static export always skips the fetch.