Add llms-txt standard support at /llms.txt and /llms-full.txt

- /llms.txt — new lightweight index with links and descriptions per
  the llms-txt standard (https://llmstxt.org/)
- /llms-full.txt — rewrites to the existing /api/llms-docs.md endpoint
  which already inlines all page content

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ThallesP

next.config.js

@@ -20,6 +20,18 @@ const nextConfig = {
   async redirects() {
     return redirects;
   },
+  async rewrites() {
+    return [
+      {
+        source: "/llms.txt",
+        destination: "/api/llms.txt",
+      },
+      {
+        source: "/llms-full.txt",
+        destination: "/api/llms-docs.md",
+      },
+    ];
+  },
 };
 
 module.exports = withContentCollections(nextConfig);

src/pages/api/llms.txt.ts

@@ -0,0 +1,97 @@
+import type { NextApiHandler } from "next";
+import { sidebarContent } from "@/data/sidebar";
+import { IPage, ISidebarSection, ISubSection } from "@/types";
+import fs from "fs";
+import path from "path";
+import matter from "gray-matter";
+
+const BASE_URL =
+  process.env.NEXT_PUBLIC_RAILWAY_DOCS_URL || "https://docs.railway.com";
+
+/**
+ * Reads the frontmatter description for a given page slug.
+ */
+function getPageDescription(slug: string): string | undefined {
+  const possiblePaths = [
+    path.join(process.cwd(), "content/docs", slug.replace(/^\//, "") + ".md"),
+    path.join(
+      process.cwd(),
+      "content/guides",
+      slug.replace(/^\/guides\//, "") + ".md",
+    ),
+  ];
+
+  for (const filePath of possiblePaths) {
+    try {
+      const fileContent = fs.readFileSync(filePath, "utf8");
+      const { data: frontMatter } = matter(fileContent);
+      return frontMatter.description;
+    } catch {
+      continue;
+    }
+  }
+
+  return undefined;
+}
+
+/**
+ * Extracts all pages from a sidebar section, handling subsections.
+ */
+function getSectionPages(section: ISidebarSection): IPage[] {
+  const pages: IPage[] = [];
+  for (const item of section.content) {
+    if ("url" in item) {
+      continue; // Skip external links
+    } else if ("subTitle" in item) {
+      const sub = item as ISubSection;
+      if (typeof sub.subTitle !== "string") {
+        pages.push(sub.subTitle);
+      }
+      for (const page of sub.pages) {
+        if (!("url" in page)) {
+          pages.push(page);
+        }
+      }
+    } else {
+      pages.push(item);
+    }
+  }
+  return pages;
+}
+
+const handler: NextApiHandler = async (_req, res) => {
+  res.setHeader("Content-Type", "text/plain; charset=utf-8");
+  res.setHeader(
+    "Cache-Control",
+    "public, s-maxage=3600, stale-while-revalidate=86400",
+  );
+
+  let content = `# Railway Documentation\n\n`;
+  content += `> Railway is a deployment platform that lets you provision infrastructure, develop locally with that infrastructure, and deploy to the cloud.\n\n`;
+  content += `- [Full documentation](${BASE_URL}/llms-full.txt): The complete Railway documentation with all page content inlined\n\n`;
+
+  for (const section of sidebarContent) {
+    const sectionTitle = section.title || "Getting Started";
+    const pages = getSectionPages(section);
+
+    if (pages.length === 0) continue;
+
+    content += `## ${sectionTitle}\n\n`;
+
+    for (const page of pages) {
+      const url = `${BASE_URL}${page.slug}`;
+      const description = getPageDescription(page.slug);
+      if (description) {
+        content += `- [${page.title}](${url}): ${description}\n`;
+      } else {
+        content += `- [${page.title}](${url})\n`;
+      }
+    }
+
+    content += "\n";
+  }
+
+  res.status(200).send(content.trimEnd() + "\n");
+};
+
+export default handler;