Next.js inapakia variables za mazingira kutoka kwa faili za .env, na kwa kanuni muhimu ya usalama: variables ni kwa ajili ya server tu kwa chaguo-msingi, na tu zile zilizo na kiambishi NEXT_PUBLIC_ zinatolewa kwa browser.
Faili
.env # loaded in all environments
.env.local # local overrides — GITIGNORED (put secrets here)
.env.development # only in `next dev`
.env.production # only in production builds
