This handles Next.js version upgrades by walking through the official migration path: detecting your current version, fetching the right upgrade guides from nextjs.org, running the appropriate codemods, and updating dependencies in the correct order. It's smart enough to recommend incremental upgrades for major version jumps instead of trying to leap from 13 to 15 in one shot. The codemod step is the real value here, since Next.js provides transforms for async Request APIs, geo/ip property migrations, and dynamic import changes that would be tedious to fix manually. Worth using if you've been putting off an upgrade because the breaking changes looked like a slog.
npx skills add https://github.com/vercel/nextjs-skills --skill next-upgrade