docs(site): generate llms.txt from documentation

README.md

@@ -65,6 +65,10 @@ Content is Markdown/MDX under `site/src/content/docs/` (`guide/`, `middleware/`,
 generated from each page's `sidebar.order` frontmatter. Every page needs a
 `title` and `description`.
 
+The build also publishes `/llms.txt` and `/next/llms.txt`. Their page links and
+descriptions come from that same content, and each index identifies its pinned
+Echo source revision. `site:check` verifies both files and their site links.
+
 ## Cookbook recipes
 
 Each folder under `cookbook/` is a self-contained example. Run one with:

site/scripts/check-site.mjs

@@ -98,5 +98,18 @@ for (const locale of ['es', 'ja', 'pt-br', 'zh-cn']) {
 for (const path of ['sitemap-index.xml', 'pagefind/pagefind.js']) {
   if (!existsSync(join(distDir, path))) problems.push(`Missing ${path}`);
 }
+for (const path of ['llms.txt', 'next/llms.txt']) {
+  const file = join(distDir, path);
+  if (!existsSync(file)) { problems.push(`Missing ${path}`); continue; }
+  const content = readFileSync(file, 'utf8');
+  if (!content.startsWith('# Echo\n')) problems.push(`${path}: missing Echo heading`);
+  for (const [, link] of content.matchAll(/\]\((https:\/\/echo\.labstack\.com\/[^)]+)\)/g)) {
+    const pathname = new URL(link).pathname;
+    const resolved = resolve(distDir, `.${pathname}`);
+    const target = extname(resolved) ? resolved : join(resolved, 'index.html');
+    if (!existsSync(target)) problems.push(`${path}: missing ${link}`);
+    checked++;
+  }
+}
 if (problems.length) throw new Error(`${problems.length} site check failure(s):\n${problems.join('\n')}`);
 console.log(`Checked ${routes.length} routes and ${checked} internal links/assets; all resolve`);

site/src/pages/llms.txt.ts

@@ -0,0 +1,61 @@
+import { getCollection } from 'astro:content';
+import type { APIRoute } from 'astro';
+import stableSource from '../../echo-source.json';
+import nextSource from '../../next-source.json';
+
+export const prerender = true;
+
+const origin = 'https://echo.labstack.com';
+const sections = [
+  { title: 'Guide', prefix: 'guide/' },
+  { title: 'Middleware', prefix: 'middleware/' },
+  { title: 'Cookbook', prefix: 'cookbook/' },
+];
+
+export const GET: APIRoute = async () => {
+  const base = import.meta.env.BASE_URL;
+  const source = base === '/next/' ? nextSource : stableSource;
+  const pages = await getCollection('docs');
+  const englishPages = pages.filter(({ id }) =>
+    !/^(?:es|ja|pt-br|zh-cn)\//.test(id),
+  );
+  const lines = [
+    '# Echo',
+    '',
+    '> Echo is a Go web framework. These docs cover setup, routing, requests, responses, middleware, and runnable examples.',
+    '',
+    `This index describes the ${source.release} docs, built against [Echo source](${source.repository.replace(/\.git$/, '')}/tree/${source.revision}). For package API signatures, see [pkg.go.dev](https://pkg.go.dev/github.com/labstack/echo/v5).`,
+    '',
+  ];
+
+  for (const { title, prefix } of sections) {
+    lines.push(`## ${title}`, '');
+    const entries = englishPages
+      .filter(({ id }) => id.startsWith(prefix))
+      .sort((a, b) =>
+        (a.data.sidebar?.order ?? 999) - (b.data.sidebar?.order ?? 999) ||
+        a.data.title.localeCompare(b.data.title),
+      );
+    for (const { id, data } of entries) {
+      const route = id.endsWith('/index') ? id.slice(0, -'/index'.length) : id;
+      lines.push(`- [${data.title}](${origin}${base}${route}/): ${data.description}`);
+    }
+    lines.push('');
+  }
+
+  lines.push('## Other versions and languages', '');
+  if (base === '/') lines.push(`- [Next version](${origin}/next/llms.txt): preview docs for the next Echo release.`);
+  else lines.push(`- [Stable version](${origin}/llms.txt): current release docs.`);
+  for (const [locale, label] of [
+    ['es', 'Español'],
+    ['ja', '日本語'],
+    ['pt-br', 'Português'],
+    ['zh-cn', '简体中文'],
+  ]) {
+    lines.push(`- [${label}](${origin}${base}${locale}/): localized documentation.`);
+  }
+
+  return new Response(`${lines.join('\n')}\n`, {
+    headers: { 'Content-Type': 'text/plain; charset=utf-8' },
+  });
+};