Build-time llms.txt, optional llms-full.txt, optional A2A Agent Cards, JSON-LD, markdown mirrors, AI crawler controls, headers, and validation for Next.js websites.

@agentmarkup/next is the Next.js adapter in the agentmarkup package family. It uses Next's config and build-adapter hooks for server deployments, and it post-processes final exported HTML when output: 'export' is enabled.

pnpm add -D @agentmarkup/next

import type { NextConfig } from 'next';
import { withAgentmarkup } from '@agentmarkup/next';

const nextConfig: NextConfig = {
  output: 'export',
};

export default withAgentmarkup(
  {
    site: 'https://example.com',
    name: 'Example',
    description: 'Machine-readable metadata for a Next.js site.',
    llmsTxt: {
      sections: [
        {
          title: 'Documentation',
          entries: [
            {
              title: 'Getting Started',
              url: '/docs/getting-started',
              description: 'Setup guide and first steps',
            },
          ],
        },
      ],
    },
    llmsFullTxt: {
      enabled: true,
    },
    markdownPages: {
      enabled: true,
    },
    contentSignalHeaders: {
      enabled: true,
    },
    globalSchemas: [
      {
        preset: 'webSite',
        name: 'Example',
        url: 'https://example.com',
      },
      {
        preset: 'organization',
        name: 'Example Inc.',
        url: 'https://example.com',
        logo: 'https://example.com/logo.png',
      },
    ],
    pages: [
      {
        path: '/faq',
        schemas: [
          {
            preset: 'faqPage',
            url: 'https://example.com/faq',
            questions: [
              {
                question: 'Do you ship internationally?',
                answer: 'Yes.',
              },
            ],
          },
        ],
      },
    ],
    aiCrawlers: {
      GPTBot: 'allow',
      ClaudeBot: 'allow',
      PerplexityBot: 'allow',
      'Google-Extended': 'allow',
      CCBot: 'disallow',
    },
    validation: {
      warnOnMissingSchema: true,
    },
  },
  nextConfig
);

• Generates optional /.well-known/agent-card.json for existing A2A services
• Generates /llms.txt from config
• Generates optional /llms-full.txt with inlined same-site markdown content
• Injects the homepage llms.txt discovery link automatically into emitted HTML pages
• Injects JSON-LD into emitted HTML pages
• Validates JSON-LD already present in emitted HTML
• Generates .md mirrors from the final exported or prerendered HTML output when a cleaner agent-facing fetch path is useful
• Configures Content-Signal and markdown-canonical headers for server deployments through next.config headers
• Generates _headers with Content-Signal and markdown-canonical Link headers for static export output
• Generates or patches robots.txt with AI crawler directives
• Validates common schema and crawler mistakes at build time
• Warns when emitted HTML looks like a thin client-rendered shell
• Warns when markdown alternate links or llms.txt mirror coverage drift out of sync
• Re-exports @agentmarkup/core helpers for custom pipeline steps or dynamic-route integration

By default, the Next adapter coexists with existing machine-readable assets. If a page already contains JSON-LD for a schema type, or the site already ships a curated llms.txt or matching crawler rules, those are preserved unless you opt into replacement.

Important: @agentmarkup/next is a final-output adapter. It works best where Next emits build-time HTML that can be patched or post-processed. If a route is fully dynamic SSR and Next does not emit an HTML file for it during build, use the re-exported @agentmarkup/core helpers directly inside your layout or page code for that route.

Markdown mirrors are optional. They are usually most useful for thin, noisy, or client-rendered HTML where the raw page is a weak fetch target for agents. The generated .md files stay directly fetchable for agents, while their server headers or _headers entries point search engines back at the HTML page as canonical.

When markdown mirrors are enabled, same-site page entries in llms.txt automatically point at the generated .md mirrors by default. Set llmsTxt.preferMarkdownMirrors: false if you want llms.txt to keep linking to HTML routes instead.

Enable llmsFullTxt when you want a richer companion file for agents that can consume more than the compact llms.txt manifest. The generated llms-full.txt keeps the same section structure but inlines same-site markdown mirror content when those mirrors exist.

Enable agentCard when you already run a real A2A-compatible agent service and want Next builds to publish its discovery file at /.well-known/agent-card.json. agentmarkup only emits and validates the static Agent Card. It does not implement the A2A runtime server or transport endpoints for you. When enabled, provide a version, at least one supportedInterfaces entry, and a non-empty description through either the top-level description or agentCard.description.

• Static export gets the full file-emission flow: HTML patching, markdown mirrors, llms.txt, llms-full.txt, robots.txt, and _headers.
• Server deployments still get generated root assets plus merged headers() rules for Content-Signal and markdown canonicals.
• On server deployments, generated root assets are written into your app's public/ directory so Next can serve them. Keep that in mind if you are comparing builds with different configs or checking generated files into source control.
• JSON-LD, discovery-link, and markdown-alternate injection only apply where Next emits HTML files at build time. Fully dynamic server-rendered routes should use the re-exported @agentmarkup/core helpers directly inside their own layout or page code.
• If the adapter hook is misconfigured, for example because a serialized config cannot be decoded or a chained adapter import fails, @agentmarkup/next now emits an explicit warning instead of silently no-oping.

Copyright (c) 2026 Sebastian Cochinescu. MIT License.

Used in production on Anima Felix.

MIT.