What is Astro's server-side rendering and API endpoints?

When Astro is configured with output: "server" (or "hybrid"), it supports SSR and API routes. SSR pages: access request context: const { cookies, request, redirect, url } = Astro. Check auth: const user = await getUser(cookies.get("session")?.value); if (!user) return redirect("/login");. API routes: create src/pages/api/users.ts: export async function GET({ request }) { const users = await db.getUsers(); return new Response(JSON.stringify(users), { headers: { "Content-Type": "application/json" } }); }. Use Astro's helpers: import { APIRoute } from 'astro'. All HTTP methods (GET, POST, PUT, DELETE, PATCH) are supported. Access form data: const data = await request.formData();. Astro uses native Web Request/Response APIs — the same standard used in Cloudflare Workers, Deno, and modern runtimes. This makes Astro API routes portable across deployment targets.