ChangelogNext.js Style Guide

Each revision is frozen at its own URL, so an agent pointed at /nextjs@2026.10/rules.md keeps the same rules until you bump it. The rule changes below are worked out from the revisions themselves. Also as Markdown.

1. Unreleased

   Live at /nextjs, not pinned yet · 192 rules

   The appendix configs now match what the template ships and what the guide's own lint and format rules accept, so a project copied from them passes pnpm lint and pnpm format:check:

   • tsconfig.json (B) adds allowJs, esModuleInterop and .next/dev/types/**/*.ts, which next dev and next typegen otherwise write into the file on first run.
   • eslint.config.mjs (C) allows default exports from *.config.mts too, for the Vitest config section 19 asks for.
   • prettier.config.mjs (D) exports a named config, which import/no-anonymous-default-export asks for, and wraps importOrder, which went past the 100-column printWidth.
   • babel.config.js and postcss.config.js (E) disable @typescript-eslint/no-require-imports on their one require() line, with a reason (NEXTJS-05.1), as the template does.
   • next.config.ts (A) says why images.remotePatterns is set, as NEXTJS-19.1 asks of every option, and wraps the pattern to fit 100 columns. The template's next.config.ts also comments its headers() option.
   • next.config.ts (A) now sends the static security headers NEXTJS-15.11 requires (X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and Strict-Transport-Security in production builds) from headers(), as the template does. The Content Security Policy needs a fresh nonce per request, so src/proxy.ts sends it.
   • The template braces its one-line if bodies in src/features/auth/schemas.ts, as the formatting table in section 5 asks.
   • src/proxy.ts (now H) sends the nonce-based Content Security Policy NEXTJS-15.11 requires, built by a new src/lib/csp.ts (G), so the appendix covers the whole rule by itself. Both match the template's files. Its matcher now covers every page except Route Handlers, build assets and prefetches, and the sign-in redirect checks the signed-in prefixes itself. "Starting a new project" moves to I.
   • eslint.config.mjs (C) and the template turn on curly: ['error', 'all'], so ESLint enforces section 5's "always braced" rule.

   Rule changes since 2026.10

   No rule changes; prose, examples or formatting only.

2. 2026.10

   Released 2026-10-19 · 192 rules
   Read 2026.10rules.mdllms.txt

   The first pinned revision: the text published as rev. 2026.10 before guides were versioned. From this revision on, /nextjs@<revision> URLs never change.

   Rules

   Initial revision: 192 rules.