From the source
Vercel introduced a Flags SDK for Next.js and SvelteKit that treats feature flags as server-side functions, enabling precomputed static pages and provider-agnostic flag management.
From the source
From the source
Vercel's Flags SDK for server-side feature flags in Next.js

Vercel introduced a Flags SDK for Next.js and SvelteKit that treats feature flags as server-side functions, enabling precomputed static pages and provider-agnostic flag management.
From the source
We recently introduced a new Flags SDK that allows using feature flags, in Next.js and SvelteKit, and works with any feature flag provider—or when using no flag provider at all.
vercel.com