next-sitemap.config.js

// Generated by scripts/generate-sitemap-excludes.js (runs during prebuild).
// Contains paths with noindex:true or a canonical pointing to a different URL.
let sitemapExcludes = [];
try {
  sitemapExcludes = require("./.sitemap-excludes.json");
} catch {
  // File not yet generated (e.g. first run without prebuild). Silently ignore.
}

// Per-page metadata { loc, lastmod, title, description } for every content
// page — used for additionalPaths so that server-rendered pages (blog,
// changelog, faq, handbook, etc.) that are NOT statically pre-built are still
// included in the sitemap, each with an accurate <lastmod> derived from git.
let allPages = [];
try {
  allPages = require("./.sitemap-all-pages.json");
} catch {
  // File not yet generated. Silently ignore.
}

const BASE_URL = process.env.CF_PAGES_URL ?? "https://langfuse.com";

// Tolerate the legacy string[] shape in case a stale cache is present.
const pageEntries = allPages.map((p) =>
  typeof p === "string" ? { loc: p } : p,
);
const pageByLoc = new Map(pageEntries.map((p) => [p.loc, p]));

// The homepage is not a content page, so it has no frontmatter date. Use the
// most recent content change as a sensible freshness signal for "/".
const latestLastmod = pageEntries.reduce((max, p) => {
  if (!p.lastmod) return max;
  return !max || Date.parse(p.lastmod) > Date.parse(max) ? p.lastmod : max;
}, undefined);

/** @type {import('next-sitemap').IConfig} */
module.exports = {
  siteUrl: BASE_URL,
  generateRobotsTxt: true,
  changefreq: "daily",
  // Never emit build-time timestamps. With autoLastmod, next-sitemap stamps
  // every page with `new Date()` on each build, making all <lastmod> values
  // identical and useless as a freshness signal for search engines and AI
  // crawlers. The real per-page lastmod is supplied via additionalPaths below.
  autoLastmod: false,
  // Provide every content page explicitly so server-rendered pages
  // (not statically built) are included. next-sitemap deduplicates: when a page
  // is also discovered from the build output, the additionalPaths entry below
  // overwrites its fields, so our accurate lastmod wins.
  additionalPaths: async () => {
    const rootLastmod = pageByLoc.get("/")?.lastmod || latestLastmod;
    const entries = [
      // Root
      {
        loc: "/",
        priority: 1,
        changefreq: "daily",
        ...(rootLastmod ? { lastmod: rootLastmod } : {}),
      },
    ];
    for (const page of pageEntries) {
      if (page.loc === "/") continue; // already added above with priority
      entries.push({
        loc: page.loc,
        changefreq: "daily",
        ...(page.lastmod ? { lastmod: page.lastmod } : {}),
      });
    }
    return entries;
  },
  exclude: [
    // Exclude _meta files and non-content routes
    "*/_meta",
    // Pages with noindex:true or a canonical override (generated by prebuild script).
    // Cookbook duplicate routes are already omitted from allPages.
    ...sitemapExcludes,
    // Exclude API routes for static export
    ...(process.env.STATIC_EXPORT === "true" ? ["/api/*"] : []),
  ],
};