seo: implement OpenAPI operation rendering and add llms documentation

apps/landing/public/llms.txt

@@ -0,0 +1,78 @@
+# Plunk
+
+> Plunk is an open-source, all-in-one email platform for developers. It unifies marketing, transactional, and broadcast email behind a single API — built to handle millions of contacts with workflows, segments, templates, and deliverability tooling out of the box.
+
+Plunk can be used as a hosted service at useplunk.com or self-hosted via Docker. Source code lives at https://github.com/useplunk/plunk.
+
+Pages listed below with a `.md` suffix serve a Markdown version (also available by requesting the same URL with `Accept: text/markdown`). Other pages are HTML only.
+
+For full product documentation, see the docs site: https://docs.useplunk.com/llms.txt
+
+## Product
+
+- [Plunk home](https://www.useplunk.com/index.md): Product overview, features, and positioning
+- [Pricing](https://www.useplunk.com/pricing.md): Plans, included volume, and overage pricing
+- [Made by humans](https://www.useplunk.com/made-by-humans): The team and story behind Plunk
+
+## Features
+
+- [Email editor](https://www.useplunk.com/features/email-editor.md): Drag-and-drop and code-based template editor
+- [Workflows](https://www.useplunk.com/features/workflows.md): Event- and segment-triggered automation flows
+- [Segments](https://www.useplunk.com/features/segments.md): Dynamic and static contact segments
+- [SMTP](https://www.useplunk.com/features/smtp.md): Send through Plunk over standard SMTP
+- [Inbound email](https://www.useplunk.com/features/inbound-email.md): Receive email at your verified domain and turn it into events
+
+## Comparisons
+
+- [Plunk vs Resend](https://www.useplunk.com/vs/resend)
+- [Plunk vs SendGrid](https://www.useplunk.com/vs/sendgrid)
+- [Plunk vs Mailchimp](https://www.useplunk.com/vs/mailchimp)
+- [Plunk vs Mailgun](https://www.useplunk.com/vs/mailgun)
+- [Plunk vs Postmark](https://www.useplunk.com/vs/postmark)
+- [Plunk vs Customer.io](https://www.useplunk.com/vs/customerio)
+- [Plunk vs Loops](https://www.useplunk.com/vs/loops)
+- [Plunk vs Brevo](https://www.useplunk.com/vs/brevo)
+- [Plunk vs ActiveCampaign](https://www.useplunk.com/vs/activecampaign)
+- [Plunk vs Klaviyo](https://www.useplunk.com/vs/klaviyo)
+- [Plunk vs ConvertKit](https://www.useplunk.com/vs/convertkit)
+- [Plunk vs Bento](https://www.useplunk.com/vs/bento)
+- [Plunk vs MailerLite](https://www.useplunk.com/vs/mailerlite)
+- [Plunk vs Amazon SES](https://www.useplunk.com/vs/amazon-ses)
+- [Plunk vs Mailjet](https://www.useplunk.com/vs/mailjet)
+- [Plunk vs Buttondown](https://www.useplunk.com/vs/buttondown)
+- [All comparisons](https://www.useplunk.com/vs)
+
+## Guides
+
+- [Email API guide](https://www.useplunk.com/guides/email-api-guide): Choosing and integrating with an email API
+- [Email deliverability](https://www.useplunk.com/guides/email-deliverability): Reaching the inbox reliably
+- [Email bounce rate](https://www.useplunk.com/guides/email-bounce-rate): What it is and how to reduce it
+- [Email open rate](https://www.useplunk.com/guides/email-open-rate): Benchmarks and improvement tactics
+- [Email click-through rate](https://www.useplunk.com/guides/email-click-through-rate): Measuring and improving CTR
+- [Email sender reputation](https://www.useplunk.com/guides/email-sender-reputation): Protecting your sending reputation
+- [Email marketing best practices](https://www.useplunk.com/guides/email-marketing-best-practices)
+- [Transactional vs marketing email](https://www.useplunk.com/guides/transactional-vs-marketing-email)
+- [What is SPF](https://www.useplunk.com/guides/what-is-spf)
+- [What is DKIM](https://www.useplunk.com/guides/what-is-dkim)
+- [What is DMARC](https://www.useplunk.com/guides/what-is-dmarc)
+- [All guides](https://www.useplunk.com/guides)
+
+## Tools
+
+- [Verify email](https://www.useplunk.com/tools/verify-email): Check a single email address for validity
+- [Spam checker](https://www.useplunk.com/tools/spam-checker): Score an email for spam triggers
+- [Markdown to email](https://www.useplunk.com/tools/markdown-to-email): Convert Markdown into HTML email
+- [SPF checker](https://www.useplunk.com/tools/spf-checker)
+- [DKIM checker](https://www.useplunk.com/tools/dkim-checker)
+- [DMARC checker](https://www.useplunk.com/tools/dmarc-checker)
+- [MX checker](https://www.useplunk.com/tools/mx-checker)
+- [Email headers analyzer](https://www.useplunk.com/tools/email-headers)
+- [All tools](https://www.useplunk.com/tools)
+
+## Optional
+
+- [Documentation](https://docs.useplunk.com): Product, API, and self-hosting docs
+- [Discord community](https://www.useplunk.com/discord)
+- [Privacy policy](https://www.useplunk.com/privacy)
+- [Terms of service](https://www.useplunk.com/terms)
+- [Data processing agreement](https://www.useplunk.com/dpa)

apps/landing/src/content/markdown-slugs.ts

@@ -0,0 +1,14 @@
+export const MARKDOWN_SLUGS: ReadonlySet<string> = new Set([
+  'index',
+  'pricing',
+  'features/workflows',
+  'features/segments',
+  'features/inbound-email',
+  'features/email-editor',
+  'features/smtp',
+]);
+
+export function hasMarkdownVariant(pathname: string): boolean {
+  const slug = pathname.replace(/^\/+|\/+$/g, '') || 'index';
+  return MARKDOWN_SLUGS.has(slug);
+}

apps/landing/src/content/pages.ts

@@ -341,3 +341,5 @@ Plunk provides SMTP credentials so you can send emails from any application or f
 [Back to features](/features) | [Pricing](/pricing) | [Documentation](https://docs.useplunk.com)
 `,
 };
+
+export {MARKDOWN_SLUGS, hasMarkdownVariant} from './markdown-slugs';

apps/landing/src/middleware.ts

@@ -1,6 +1,8 @@
 import { NextResponse } from 'next/server';
 import type { NextRequest } from 'next/server';
 
+import { hasMarkdownVariant } from './content/markdown-slugs';
+
 type Negotiated = 'markdown' | 'html' | 'none';
 
 function parseAccept(accept: string): Array<{ type: string; q: number }> {
@@ -59,6 +61,9 @@ export function middleware(request: NextRequest) {
 
   const response = NextResponse.next();
   response.headers.set('Vary', 'Accept');
+  if (hasMarkdownVariant(pathname)) {
+    response.headers.append('Link', `<${pathname}.md>; rel="alternate"; type="text/markdown"`);
+  }
   return response;
 }
 

apps/landing/src/pages/_app.tsx

@@ -2,9 +2,11 @@ import '../styles/globals.css';
 import React, {useEffect} from 'react';
 import Head from 'next/head';
 import {AppProps} from 'next/app';
+import {useRouter} from 'next/router';
 import {toast, Toaster} from 'sonner';
 import {SWRConfig} from 'swr';
 import {network} from '../lib/network';
+import {hasMarkdownVariant} from '../content/markdown-slugs';
 import {DefaultSeo} from 'next-seo';
 import Script from 'next/script';
 import {Bricolage_Grotesque, Hanken_Grotesk, JetBrains_Mono} from 'next/font/google';
@@ -37,6 +39,10 @@ const mono = JetBrains_Mono({
  * @param props.pageProps
  */
 function App({Component, pageProps}: AppProps) {
+  const router = useRouter();
+  const pathname = (router.asPath.split('?')[0] ?? '').split('#')[0] ?? '/';
+  const markdownHref = hasMarkdownVariant(pathname) ? `${pathname === '/' ? '/index' : pathname}.md` : null;
+
   useEffect(() => {
     const searchParams = new URLSearchParams(window.location.search);
     const message = searchParams.get('message');
@@ -51,6 +57,7 @@ function App({Component, pageProps}: AppProps) {
       <Head>
         <title>Plunk | The Open-Source Email Platform</title>
         <meta name="viewport" content="width=device-width, initial-scale=1.0" key={'viewport'} />
+        {markdownHref && <link rel="alternate" type="text/markdown" href={markdownHref} />}
       </Head>
       <Toaster position={'top-right'} />