diff --git a/web/app/download/download.module.css b/web/app/download/download.module.css
new file mode 100644
index 00000000..5511f69b
--- /dev/null
+++ b/web/app/download/download.module.css
@@ -0,0 +1,266 @@
+.page {
+  min-height: 100svh;
+  background: var(--bg);
+  color: var(--fg);
+  font-family: var(--font-geist-sans), sans-serif;
+  -webkit-font-smoothing: antialiased;
+  transition:
+    background 0.3s ease,
+    color 0.3s ease;
+}
+
+.main {
+  max-width: 72rem;
+  margin: 0 auto;
+  padding: 3.5rem 1.25rem 5rem;
+}
+
+/* ── Hero ── */
+
+.hero {
+  text-align: center;
+  padding: 1rem 0 2.75rem;
+}
+
+.eyebrow {
+  font-size: 0.72rem;
+  font-weight: 700;
+  letter-spacing: 0.14em;
+  text-transform: uppercase;
+  color: var(--primary);
+  margin: 0 0 12px;
+}
+
+.headline {
+  font-family: var(--font-heading), sans-serif;
+  font-size: clamp(2.4rem, 6vw, 4rem);
+  font-weight: 700;
+  letter-spacing: -0.04em;
+  color: var(--primary);
+  margin: 0 0 16px;
+}
+
+.lead {
+  max-width: 42rem;
+  margin: 0 auto;
+  color: var(--fg-muted);
+  font-size: 1.05rem;
+  line-height: 1.7;
+}
+
+.recommendation {
+  width: fit-content;
+  max-width: 100%;
+  margin: 2rem auto 0;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 0.65rem;
+}
+
+.detected {
+  margin: 0;
+  color: var(--fg-faint);
+  font-size: 0.8rem;
+  font-weight: 600;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+}
+
+.primary {
+  composes: btn btn-primary from global;
+  min-height: 56px;
+  padding: 16px 28px;
+  font-size: 1.0625rem;
+  gap: 10px;
+}
+
+.installNote {
+  margin: 0;
+  color: var(--fg-muted);
+  font-size: 0.9rem;
+  line-height: 1.5;
+}
+
+.warning {
+  max-width: 36rem;
+  margin: 0.25rem auto 0;
+  color: var(--fg-faint);
+  font-size: 0.82rem;
+  line-height: 1.55;
+}
+
+.warning em {
+  color: var(--fg-muted);
+  font-style: italic;
+}
+
+.warning strong {
+  color: var(--fg-muted);
+  font-weight: 600;
+}
+
+.choose {
+  margin: 1.75rem 0 0;
+  color: var(--fg-muted);
+  font-size: 0.95rem;
+}
+
+/* ── Platform cards ── */
+
+.platforms {
+  display: grid;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 1rem;
+  margin-top: 1rem;
+}
+
+.platform {
+  display: flex;
+  flex-direction: column;
+  gap: 1.1rem;
+  padding: 1.35rem;
+  border: 1px solid var(--line);
+  border-radius: var(--r-lg);
+  background: var(--card-bg);
+  transition:
+    border-color 0.2s,
+    box-shadow 0.2s;
+}
+
+.platformRecommended {
+  border-color: color-mix(in srgb, var(--primary) 55%, var(--line));
+  box-shadow: 0 2px 20px color-mix(in srgb, var(--primary) 8%, transparent);
+}
+
+.platformHeader h2 {
+  margin: 0 0 0.45rem;
+  font-family: var(--font-heading), sans-serif;
+  font-size: 1.35rem;
+  letter-spacing: -0.02em;
+  color: var(--fg);
+}
+
+.platformHeader p {
+  margin: 0;
+  color: var(--fg-muted);
+  font-size: 0.9rem;
+  line-height: 1.55;
+}
+
+.choices {
+  display: flex;
+  flex-direction: column;
+  gap: 0.55rem;
+}
+
+.choice {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 0.75rem;
+  min-height: 48px;
+  padding: 0.7rem 0.9rem;
+  border: 1px solid var(--line);
+  border-radius: var(--r-md);
+  background: var(--surface);
+  color: var(--fg);
+  text-decoration: none;
+  transition:
+    border-color 0.2s,
+    background 0.2s;
+}
+
+@media (hover: hover) and (pointer: fine) {
+  .choice:hover {
+    border-color: var(--primary);
+    background: var(--secondary-surface);
+  }
+}
+
+.choiceRecommended {
+  border-color: var(--primary);
+  background: color-mix(in srgb, var(--primary) 10%, var(--surface));
+}
+
+.choiceArch {
+  font-size: 0.92rem;
+  font-weight: 600;
+}
+
+.choiceFormat {
+  color: var(--fg-faint);
+  font-family: var(--font-geist-mono), monospace;
+  font-size: 0.78rem;
+}
+
+.alternative {
+  margin: -0.35rem 0 0;
+  color: var(--fg-faint);
+  font-size: 0.82rem;
+}
+
+.alternative a {
+  color: var(--primary);
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
+.platformNote {
+  margin: auto 0 0;
+  color: var(--fg-faint);
+  font-size: 0.78rem;
+  line-height: 1.55;
+}
+
+/* ── Release note ── */
+
+.releaseNote {
+  max-width: 46rem;
+  margin: 2.5rem auto 0;
+  padding-top: 1.75rem;
+  border-top: 1px solid var(--line);
+  text-align: center;
+  color: var(--fg-faint);
+  font-size: 0.86rem;
+  line-height: 1.65;
+}
+
+.releaseNote p {
+  margin: 0.4rem 0;
+}
+
+.releaseNote a {
+  color: var(--primary);
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
+@media (max-width: 900px) {
+  .platforms {
+    grid-template-columns: 1fr;
+  }
+
+  .main {
+    padding-top: 2.5rem;
+  }
+}
+
+@media (max-width: 560px) {
+  .main {
+    padding-inline: 1rem;
+  }
+
+  .headline {
+    font-size: clamp(2.1rem, 10vw, 2.8rem);
+  }
+
+  .primary {
+    width: 100%;
+    justify-content: center;
+  }
+
+  .platform {
+    padding: 1.1rem;
+  }
+}
diff --git a/web/app/download/page.tsx b/web/app/download/page.tsx
new file mode 100644
index 00000000..e9c452a7
--- /dev/null
+++ b/web/app/download/page.tsx
@@ -0,0 +1,188 @@
+import type { Metadata } from 'next';
+import { headers } from 'next/headers';
+
+import { cn } from '../../lib/utils';
+import { SiteFooter } from '../../components/SiteFooter';
+import { SiteNav } from '../../components/SiteNav';
+import {
+  LINUX_TARBALLS,
+  WINDOWS_PORTABLE,
+  detectDesktopDownload,
+  downloadLabel,
+  downloadsFor,
+  platformName,
+  type DesktopPlatform,
+} from '../../lib/desktop-downloads';
+import { defaultOgImage } from '../../lib/og-meta';
+import { absoluteUrl, SITE_NAME } from '../../lib/site';
+import s from './download.module.css';
+
+// The recommendation comes from the request's User-Agent, so each visitor
+// gets their platform's download in the first response.
+export const dynamic = 'force-dynamic';
+
+const TITLE = 'Download Agent Relay for macOS, Windows, and Linux';
+const DESCRIPTION =
+  'Download Agent Relay for macOS, Windows, or Linux. The same local relay for Claude Code, Codex, and your other agents on every desktop platform.';
+
+export const metadata: Metadata = {
+  title: TITLE,
+  description: DESCRIPTION,
+  alternates: {
+    canonical: absoluteUrl('/download'),
+  },
+  openGraph: {
+    siteName: SITE_NAME,
+    title: TITLE,
+    description: DESCRIPTION,
+    url: absoluteUrl('/download'),
+    type: 'website',
+    images: [defaultOgImage()],
+  },
+  twitter: {
+    card: 'summary_large_image',
+    title: TITLE,
+    description: DESCRIPTION,
+    images: [defaultOgImage().url],
+  },
+};
+
+const platforms: Array<{
+  id: DesktopPlatform;
+  name: string;
+  blurb: string;
+  note: string;
+}> = [
+  {
+    id: 'macos',
+    name: 'macOS',
+    blurb: 'For Apple silicon and Intel Macs.',
+    note: 'Requires macOS 13 or later. Open the disk image and drag Agent Relay to Applications.',
+  },
+  {
+    id: 'windows',
+    name: 'Windows',
+    blurb: 'For Intel, AMD, and Arm PCs.',
+    note: 'Windows 10 and 11. Run the installer: it installs for your account without administrator rights. Releases are not code-signed yet, so SmartScreen may ask once; Smart App Control must be off.',
+  },
+  {
+    id: 'linux',
+    name: 'Linux',
+    blurb: 'For x64 and arm64 distributions.',
+    note: 'Install the .deb with your package manager, or use a tarball if you prefer a relocatable install.',
+  },
+];
+
+export default async function DownloadPage() {
+  const requestHeaders = await headers();
+  const detected = detectDesktopDownload({
+    userAgent: requestHeaders.get('user-agent') ?? '',
+    platform: requestHeaders.get('sec-ch-ua-platform'),
+    architecture: requestHeaders.get('sec-ch-ua-arch'),
+  });
+
+  return (
+    <div className={s.page}>
+      <SiteNav />
+
+      <main className={s.main}>
+        <section className={s.hero}>
+          <p className={s.eyebrow}>Agent Relay Desktop</p>
+          <h1 className={s.headline}>Download Agent Relay</h1>
+          <p className={s.lead}>
+            The same window for your local agents on macOS, Windows, and Linux. Sign in once and your
+            sessions, agents, and messages are there.
+          </p>
+
+          {detected ? (
+            <div className={s.recommendation}>
+              <p className={s.detected}>
+                Detected {platformName(detected.platform)}
+                {detected.arch === 'arm64' ? ' on Arm' : ''}
+              </p>
+              <a className={s.primary} href={detected.url}>
+                {downloadLabel(detected)}
+              </a>
+              <p className={s.installNote}>{detected.installNote}</p>
+              {detected.platform === 'windows' ? (
+                <p className={s.warning}>
+                  The Windows installer is not code-signed yet: SmartScreen may show <em>Windows protected your PC</em>{' '}
+                  once. Choose <strong>More info</strong> → <strong>Run anyway</strong>.
+                </p>
+              ) : null}
+            </div>
+          ) : (
+            <p className={s.choose}>Choose the download for your computer.</p>
+          )}
+        </section>
+
+        <section className={s.platforms} aria-label="All downloads">
+          {platforms.map((platform) => {
+            const items = downloadsFor(platform.id);
+            const isRecommended = detected?.platform === platform.id;
+
+            return (
+              <article
+                key={platform.id}
+                className={cn(s.platform, isRecommended && s.platformRecommended)}
+              >
+                <header className={s.platformHeader}>
+                  <h2>{platform.name}</h2>
+                  <p>{platform.blurb}</p>
+                </header>
+
+                <div className={s.choices}>
+                  {items.map((item) => {
+                    const isRecommendedChoice =
+                      detected?.platform === item.platform && detected.arch === item.arch;
+
+                    return (
+                      <a
+                        key={`${item.platform}-${item.arch}`}
+                        className={cn(s.choice, isRecommendedChoice && s.choiceRecommended)}
+                        href={item.url}
+                        aria-label={`${downloadLabel(item)} — ${item.filename}`}
+                      >
+                        <span className={s.choiceArch}>{item.archLabel}</span>
+                        <span className={s.choiceFormat}>.{item.format}</span>
+                      </a>
+                    );
+                  })}
+                </div>
+
+                {platform.id === 'windows' ? (
+                  <p className={s.alternative}>
+                    Prefer portable? <a href={WINDOWS_PORTABLE.x64}>x64 .zip</a> or{' '}
+                    <a href={WINDOWS_PORTABLE.arm64}>arm64 .zip</a>
+                  </p>
+                ) : null}
+
+                {platform.id === 'linux' ? (
+                  <p className={s.alternative}>
+                    Prefer a tarball? <a href={LINUX_TARBALLS.x64}>x64</a> or <a href={LINUX_TARBALLS.arm64}>arm64</a>
+                  </p>
+                ) : null}
+
+                <p className={s.platformNote}>{platform.note}</p>
+              </article>
+            );
+          })}
+        </section>
+
+        <section className={s.releaseNote}>
+          <p>
+            Every link points at the latest release, so it always serves the newest version. Each release also
+            publishes version-pinned files and a SHA-256 checksum for every download.
+          </p>
+          <p>
+            <a href="https://github.com/AgentWorkforce/relay-desktop-releases/releases/latest">
+              See the latest release, checksums, and version history
+            </a>
+          </p>
+        </section>
+      </main>
+
+      <SiteFooter />
+    </div>
+  );
+}
diff --git a/web/app/sitemap.ts b/web/app/sitemap.ts
index 21b8901c..27404a28 100644
--- a/web/app/sitemap.ts
+++ b/web/app/sitemap.ts
@@ -21,6 +21,12 @@ export default function sitemap(): MetadataRoute.Sitemap {
       changeFrequency: 'weekly',
       priority: 1.0,
     },
+    {
+      url: absoluteUrl('/download'),
+      lastModified: now,
+      changeFrequency: 'weekly',
+      priority: 0.9,
+    },
     {
       url: absoluteUrl('/pear'),
       lastModified: now,
diff --git a/web/components/SiteFooter.tsx b/web/components/SiteFooter.tsx
index 39c34ba5..d30b63b0 100644
--- a/web/components/SiteFooter.tsx
+++ b/web/components/SiteFooter.tsx
@@ -21,6 +21,7 @@ const footerColumns: FooterColumn[] = [
     title: 'Products',
     links: [
       { label: 'Relay Cloud', href: 'https://agentrelay.com/cloud' },
+      { label: 'Download', href: '/download' },
       { label: 'Flows', href: '/flows' },
       { label: 'Skip', href: 'https://heyskip.dev' },
       { label: 'Pear', href: '/pear' },
diff --git a/web/components/SiteNav.tsx b/web/components/SiteNav.tsx
index b91f0453..e49f3f69 100644
--- a/web/components/SiteNav.tsx
+++ b/web/components/SiteNav.tsx
@@ -101,6 +101,11 @@ export function SiteNav({
                     Log in
                   </a>
                 </li>
+                <li>
+                  <Link href="/download" className={s.link}>
+                    Download
+                  </Link>
+                </li>
                 <li>
                   <Link href="/docs" className={s.link}>
                     Docs
@@ -172,6 +177,11 @@ export function SiteNav({
                 Log in
               </a>
             )}
+            {!hideLinks && (
+              <Link href="/download" className={s.mobileLink} onClick={() => setMenuOpen(false)}>
+                Download
+              </Link>
+            )}
             {!hideLinks && !hideMobileDocsLink && (
               <Link href="/docs" className={s.mobileLink} onClick={() => setMenuOpen(false)}>
                 Docs
diff --git a/web/lib/desktop-downloads.ts b/web/lib/desktop-downloads.ts
new file mode 100644
index 00000000..d0216847
--- /dev/null
+++ b/web/lib/desktop-downloads.ts
@@ -0,0 +1,176 @@
+const RELEASES = 'https://github.com/AgentWorkforce/relay-desktop-releases/releases/latest/download';
+
+export type DesktopPlatform = 'macos' | 'windows' | 'linux';
+export type DesktopArch = 'arm64' | 'x64';
+export type DesktopDownloadFormat = 'dmg' | 'exe' | 'zip' | 'deb';
+
+export type DesktopDownload = {
+  platform: DesktopPlatform;
+  arch: DesktopArch;
+  format: DesktopDownloadFormat;
+  filename: string;
+  url: string;
+  /** Short architecture name for a button, such as "Apple silicon" or "x64". */
+  archLabel: string;
+  /** What to do with the file once it arrives. */
+  installNote: string;
+};
+
+const download = (
+  platform: DesktopPlatform,
+  arch: DesktopArch,
+  format: DesktopDownloadFormat,
+  filename: string,
+  archLabel: string,
+  installNote: string,
+): DesktopDownload => ({
+  platform,
+  arch,
+  format,
+  filename,
+  url: `${RELEASES}/${filename}`,
+  archLabel,
+  installNote,
+});
+
+/**
+ * Every download link the website offers, one entry per platform and
+ * architecture. The stable asset names are published by relay-desktop's
+ * Release workflow, so these URLs follow a new release without a website
+ * deploy.
+ */
+export const DESKTOP_DOWNLOADS: readonly DesktopDownload[] = [
+  download(
+    'macos',
+    'arm64',
+    'dmg',
+    'AgentRelay-macOS-arm64.dmg',
+    'Apple silicon',
+    'Open the disk image and drag Agent Relay to Applications.',
+  ),
+  download(
+    'macos',
+    'x64',
+    'dmg',
+    'AgentRelay-macOS-x64.dmg',
+    'Intel',
+    'Open the disk image and drag Agent Relay to Applications.',
+  ),
+  download(
+    'windows',
+    'x64',
+    'exe',
+    'AgentRelay-Windows-x64-Setup.exe',
+    'x64',
+    'Run the installer. It installs for your account without administrator rights.',
+  ),
+  download(
+    'windows',
+    'arm64',
+    'exe',
+    'AgentRelay-Windows-arm64-Setup.exe',
+    'Arm64',
+    'Run the installer. It installs for your account without administrator rights.',
+  ),
+  download(
+    'linux',
+    'x64',
+    'deb',
+    'AgentRelay-Linux-x64.deb',
+    'x64',
+    'Install the .deb with your package manager.',
+  ),
+  download(
+    'linux',
+    'arm64',
+    'deb',
+    'AgentRelay-Linux-arm64.deb',
+    'arm64',
+    'Install the .deb with your package manager.',
+  ),
+];
+
+/**
+ * The zips are the portable alternative to the Windows installer: unpack one
+ * and run agent-relay.exe without installing anything.
+ */
+export const WINDOWS_PORTABLE: Record<DesktopArch, string> = {
+  x64: `${RELEASES}/AgentRelay-Windows-x64.zip`,
+  arm64: `${RELEASES}/AgentRelay-Windows-arm64.zip`,
+};
+
+export const LINUX_TARBALLS: Record<DesktopArch, string> = {
+  x64: `${RELEASES}/AgentRelay-Linux-x64.tar.gz`,
+  arm64: `${RELEASES}/AgentRelay-Linux-arm64.tar.gz`,
+};
+
+export function platformName(platform: DesktopPlatform): string {
+  if (platform === 'macos') return 'macOS';
+  if (platform === 'windows') return 'Windows';
+  return 'Linux';
+}
+
+export function downloadsFor(platform: DesktopPlatform): DesktopDownload[] {
+  return DESKTOP_DOWNLOADS.filter((item) => item.platform === platform);
+}
+
+export function downloadFor(platform: DesktopPlatform, arch: DesktopArch): DesktopDownload {
+  const match = DESKTOP_DOWNLOADS.find((item) => item.platform === platform && item.arch === arch);
+  if (!match) throw new Error(`No ${platform} ${arch} download`);
+  return match;
+}
+
+export function downloadLabel(item: DesktopDownload): string {
+  return `Download for ${platformName(item.platform)} (${item.archLabel})`;
+}
+
+export type DesktopDetectInput = {
+  userAgent: string;
+  /** `navigator.platform`, or the quoted `Sec-CH-UA-Platform` request header. */
+  platform?: string | null;
+  /** `Sec-CH-UA-Arch`, when a browser sends it. */
+  architecture?: string | null;
+};
+
+/**
+ * Work out which download to put first. Runs on the server from the request's
+ * User-Agent (and Client Hint headers), so Windows visitors get the Windows
+ * build in the first response instead of a Mac download that swaps after
+ * hydration. When the platform is unclear, the page shows every option.
+ */
+export function detectDesktopDownload(input: DesktopDetectInput): DesktopDownload | null {
+  const userAgent = input.userAgent ?? '';
+  const platformHint = (input.platform ?? '').replaceAll('"', '').toLowerCase();
+
+  // Phones, tablets, and ChromeOS are not desktop installs.
+  if (/iphone|ipad|ipod|android|windows phone|mobile/i.test(userAgent) || /cros/i.test(userAgent)) {
+    return null;
+  }
+
+  let platform: DesktopPlatform | null = null;
+  if (platformHint.includes('windows') || /windows|win32|win64/i.test(userAgent)) {
+    platform = 'windows';
+  } else if (platformHint.includes('mac') || /macintosh|mac os x/i.test(userAgent)) {
+    platform = 'macos';
+  } else if (platformHint.includes('linux') || /linux|x11/i.test(userAgent)) {
+    platform = 'linux';
+  }
+
+  if (!platform) return null;
+
+  return downloadFor(platform, detectArch(platform, userAgent, input.architecture));
+}
+
+function detectArch(
+  platform: DesktopPlatform,
+  userAgent: string,
+  architecture: string | null | undefined,
+): DesktopArch {
+  const hint = (architecture ?? '').replaceAll('"', '').toLowerCase();
+  if (hint === 'arm' || /arm64|aarch64|armv8/i.test(userAgent)) return 'arm64';
+  if (hint === 'x86' || /x86_64|amd64|win64/i.test(userAgent)) return 'x64';
+
+  // Safari does not expose the Mac's architecture. Apple silicon is the
+  // common case; Intel Macs can still choose Intel from the options below.
+  return platform === 'macos' ? 'arm64' : 'x64';
+}
diff --git a/web/lib/test/desktop-downloads.test.ts b/web/lib/test/desktop-downloads.test.ts
new file mode 100644
index 00000000..0439a0fc
--- /dev/null
+++ b/web/lib/test/desktop-downloads.test.ts
@@ -0,0 +1,84 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  LINUX_TARBALLS,
+  WINDOWS_PORTABLE,
+  downloadFor,
+  detectDesktopDownload,
+  downloadLabel,
+} from '../desktop-downloads';
+
+const WINDOWS_X64 =
+  'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36';
+const WINDOWS_ARM64 =
+  'Mozilla/5.0 (Windows NT 10.0; Win64; ARM64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36';
+const MAC_APPLE_SILICON =
+  'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.6 Safari/605.1.15';
+const LINUX_X64 =
+  'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36';
+
+describe('desktop downloads', () => {
+  it('detects Windows and recommends the Windows installer, not the Mac disk image', () => {
+    const detected = detectDesktopDownload({ userAgent: WINDOWS_X64 });
+
+    expect(detected?.platform).toBe('windows');
+    expect(detected?.arch).toBe('x64');
+    expect(detected?.filename).toBe('AgentRelay-Windows-x64-Setup.exe');
+    expect(detected?.url).toBe(
+      'https://github.com/AgentWorkforce/relay-desktop-releases/releases/latest/download/AgentRelay-Windows-x64-Setup.exe',
+    );
+    expect(downloadLabel(detected!)).toBe('Download for Windows (x64)');
+  });
+
+  it('uses Client Hints or the user agent to pick the Arm installer', () => {
+    expect(
+      detectDesktopDownload({ userAgent: WINDOWS_X64, architecture: '"arm"' })?.filename,
+    ).toBe('AgentRelay-Windows-arm64-Setup.exe');
+    expect(detectDesktopDownload({ userAgent: WINDOWS_ARM64 })?.filename).toBe(
+      'AgentRelay-Windows-arm64-Setup.exe',
+    );
+  });
+
+  it('uses the Sec-CH-UA-Platform header when the user agent is reduced', () => {
+    expect(
+      detectDesktopDownload({ userAgent: 'Mozilla/5.0', platform: '"Windows"' })?.platform,
+    ).toBe('windows');
+    expect(
+      detectDesktopDownload({ userAgent: 'Mozilla/5.0', platform: '"macOS"' })?.platform,
+    ).toBe('macos');
+  });
+
+  it('defaults Macs to Apple silicon and honors an Intel Client Hint', () => {
+    expect(detectDesktopDownload({ userAgent: MAC_APPLE_SILICON })?.filename).toBe(
+      'AgentRelay-macOS-arm64.dmg',
+    );
+    expect(
+      detectDesktopDownload({ userAgent: MAC_APPLE_SILICON, architecture: '"x86"' })?.filename,
+    ).toBe('AgentRelay-macOS-x64.dmg');
+  });
+
+  it('detects Linux and links both package formats', () => {
+    expect(detectDesktopDownload({ userAgent: LINUX_X64 })?.filename).toBe('AgentRelay-Linux-x64.deb');
+    expect(LINUX_TARBALLS.x64).toMatch(/AgentRelay-Linux-x64\.tar\.gz$/);
+    expect(LINUX_TARBALLS.arm64).toMatch(/AgentRelay-Linux-arm64\.tar\.gz$/);
+  });
+
+  it('offers every option when the platform is unclear or not a desktop', () => {
+    expect(detectDesktopDownload({ userAgent: 'curl/8.0' })).toBeNull();
+    expect(
+      detectDesktopDownload({
+        userAgent:
+          'Mozilla/5.0 (iPhone; CPU iPhone OS 18_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0 Mobile/15E148 Safari/604.1',
+      }),
+    ).toBeNull();
+    expect(
+      detectDesktopDownload({
+        userAgent:
+          'Mozilla/5.0 (X11; CrOS x86_64 14541.0.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36',
+      }),
+    ).toBeNull();
+    expect(downloadFor('windows', 'arm64').format).toBe('exe');
+    expect(WINDOWS_PORTABLE.x64).toMatch(/AgentRelay-Windows-x64\.zip$/);
+    expect(WINDOWS_PORTABLE.arm64).toMatch(/AgentRelay-Windows-arm64\.zip$/);
+  });
+});