Cloudflare Workers

/**
 * Jamdesk Documentation Proxy Worker
 *
 * Generated by: jamdesk deploy-proxy cloudflare
 * Proxies /docs/* requests AND their assets to YOUR_SLUG.jamdesk.app
 *
 * Assets under /_jd/* (images, fonts, branding, analytics) must also be proxied
 * since they use absolute paths in the HTML.
 */

const JAMDESK_HOST = "YOUR_SLUG.jamdesk.app";

// Paths that are always proxied to Jamdesk
const PROXY_PATHS = [
  "/docs",  // Documentation pages
  "/_jd/",  // All Jamdesk assets (images, fonts, branding, analytics)
];

function shouldProxy(pathname) {
  return PROXY_PATHS.some(prefix => {
    // For the docs path, require exact match or prefix with slash (not /docs.json)
    if (prefix === "/docs") {
      return pathname === "/docs" || pathname.startsWith("/docs/");
    }
    return pathname.startsWith(prefix);
  });
}

function proxyToJamdesk(request, url) {
  // Rewrite the request to Jamdesk
  const proxyUrl = new URL(request.url);
  proxyUrl.hostname = JAMDESK_HOST;
  // Pin the scheme: an http:// visitor proxied as http:// gets a 308 from
  // Vercel's edge pointing at JAMDESK_HOST, and redirect:"manual" hands that
  // redirect straight to the browser — bouncing the visitor off this domain.
  proxyUrl.protocol = "https:";
  // Setting .protocol leaves a non-default .port in place, so :8787 (wrangler
  // dev) or Cloudflare's alternate http ports (8080, 8880, 2052…) would follow
  // us to the https upstream and fail there.
  proxyUrl.port = "";

  // Clone headers and add proxy headers
  const headers = new Headers(request.headers);
  headers.set("Host", JAMDESK_HOST);
  headers.set("X-Forwarded-Host", url.hostname);
  headers.set("X-Forwarded-Proto", "https");
  // Custom header for domain verification (Vercel strips standard forwarding headers)
  headers.set("X-Jamdesk-Forwarded-Host", url.hostname);

  // Don't follow redirects — let the browser handle them so the URL updates.
  // Without this, redirects happen internally and the browser URL doesn't change,
  // which causes the sidebar to mis-highlight the active page.
  const proxyRequest = new Request(proxyUrl, {
    method: request.method,
    headers,
    body: request.body,
    redirect: "manual",
  });

  // Cache all content types at Cloudflare edge (CF doesn't cache HTML by default).
  // Cache duration is controlled by upstream Cache-Control headers.
  // Never cache redirects or errors — they must always hit origin.
  return fetch(proxyRequest, {
    cf: {
      cacheEverything: true,
      cacheTtlByStatus: { "300-399": 0, "400-499": 0, "500-599": 0 },
    },
  });
}

export default {
  async fetch(request) {
    const url = new URL(request.url);

    if (shouldProxy(url.pathname)) {
      return proxyToJamdesk(request, url);
    }

    // /_next/ is ambiguous: the customer's root site may itself be a Next.js app
    // serving its own /_next/ assets. Try the origin first and fall back to
    // Jamdesk when the origin doesn't have it (404) or can't answer at all
    // (5xx — a docs-only domain has no real origin, so Cloudflare returns 522).
    // Hashed asset filenames never collide between the two apps.
    if (url.pathname.startsWith("/_next/")) {
      let originResponse;
      try {
        originResponse = await fetch(request);
      } catch (err) {
        // Log rather than swallow: a genuine platform fault and a domain with
        // no origin at all are indistinguishable in `wrangler tail` otherwise.
        console.warn("origin fetch threw, serving from Jamdesk:", err);
        return proxyToJamdesk(request, url);
      }
      if (originResponse.status !== 404 && originResponse.status < 500) {
        return originResponse;
      }
      return proxyToJamdesk(request, url);
    }

    return fetch(request);
  },
};

name = "docs-proxy"
main = "index.js"
compatibility_date = "2024-01-01"

# Serve only via the routes below, not on the public <name>.workers.dev URL —
# that URL is a second way into the same proxy and is worth closing.
workers_dev = false

# Single catch-all route; the worker handles path filtering internally
routes = [
  { pattern = "yoursite.com/*", zone_name = "yoursite.com" },
]