A Next.js site that keeps its posts or pages as Markdown files
in the repository works with a content map in orbit.config.yaml: where the
files are and which route renders them (app/posts/[slug]/page.tsx, say). Without
a field list, Orbit works the form out from your posts. Images in public/ are
referenced from the site root, the way Next serves them.
Tested on Next.js 16 with two sites, both in Orbit Extras ready to use: Next’s own blog example, and Vercel’s portfolio starter, whose posts are MDX. Content that lives in a headless CMS or a database isn’t in the repository, so Orbit can’t edit it.