The next-config package is a configuration package for Next.js. It is used to configure the Next.js app and is located in the packages/next-config directory.

Images

The package configures Next.js image optimization to support AVIF and WebP formats. It also sets up remote patterns to allow loading images from Clerk securely (i.e. profile images).

Prisma

For server-side builds, the package includes the Prisma plugin which helps handle Prisma in a Next.js monorepo setup correctly.

Rewrites

The package configures URL rewrites to handle PostHog analytics integration:

  • /ingest/static/:path* routes to PostHog’s static assets
  • /ingest/:path* routes to the main PostHog ingestion endpoint
  • /ingest/decide routes to PostHog’s feature flags endpoint

It also enables skipTrailingSlashRedirect to properly support PostHog API requests with trailing slashes.

OpenTelemetry

The package includes a fix for OpenTelemetry instrumentation warnings by configuring webpack to ignore warnings from @opentelemetry/instrumentation packages.

The configuration can optionally be wrapped with withAnalyzer() to enable bundle analysis capabilities.