diff --git a/app/en/resources/contact-us/contact-cards.tsx b/app/en/resources/contact-us/contact-cards.tsx
index 9e2e720a9..1c4cd5ad1 100644
--- a/app/en/resources/contact-us/contact-cards.tsx
+++ b/app/en/resources/contact-us/contact-cards.tsx
@@ -20,7 +20,7 @@ import {
   Users,
 } from "lucide-react";
 import posthog from "posthog-js";
-import { useState } from "react";
+import { useEffect, useState } from "react";
 import { useForm } from "react-hook-form";
 import { QuickStartCard } from "../../../_components/quick-start-card";
 
@@ -264,6 +264,14 @@ function SuccessMessage({ onClose }: { onClose: () => void }) {
 export function ContactCards() {
   const [isSalesModalOpen, setIsSalesModalOpen] = useState(false);
   const [isSubmitted, setIsSubmitted] = useState(false);
+  // Assemble the support mailto only after mount so the SSR/crawled markup
+  // shows a plain contact-page link — Cloudflare's email obfuscation then has
+  // nothing to rewrite into a broken /cdn-cgi/l/email-protection link. Mirrors
+  // <ContactEmail> (see app/_components/contact-email.tsx).
+  const [supportHref, setSupportHref] = useState("/en/resources/contact-us");
+  useEffect(() => {
+    setSupportHref("mailto:support@arcade.dev");
+  }, []);
 
   const handleContactSalesClick = () => {
     posthog.capture("Contact sales modal opened", {
@@ -282,7 +290,7 @@ export function ContactCards() {
       <div className="mt-16 grid gap-8 md:grid-cols-2 lg:grid-cols-3">
         <QuickStartCard
           description="Get help with technical issues, account questions, and general inquiries from our support team.  Email support is available for customers on paid plans."
-          href="mailto:support@arcade.dev"
+          href={supportHref}
           icon={Mail}
           title="Email Support"
         />
diff --git a/next.config.ts b/next.config.ts
index c0c5b2062..c3347c3d6 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -31,6 +31,13 @@ const nextConfig: NextConfig = withLlmsTxt({
           destination: "/:locale/resources/integrations",
           permanent: true,
         },
+        // The auth provider is "square"; an external/stale link points at the
+        // old "squareup" slug, which 404s. Send it to the real page.
+        {
+          source: "/:locale/references/auth-providers/squareup",
+          destination: "/:locale/references/auth-providers/square",
+          permanent: true,
+        },
         // Dissolved guides/security section
         {
           source: "/:locale/guides/security/security-research-program",
diff --git a/tests/integration-index-links.test.ts b/tests/integration-index-links.test.ts
index 637b46a2f..b2f5dd158 100644
--- a/tests/integration-index-links.test.ts
+++ b/tests/integration-index-links.test.ts
@@ -8,8 +8,13 @@ import {
   resolveIndexToolkits,
   toIntegrationLink,
 } from "@/app/_lib/integration-index";
-import type { ToolkitWithDocsLink } from "@/app/_lib/toolkit-slug";
+import { readToolkitData } from "@/app/_lib/toolkit-data";
 import {
+  getToolkitSlug,
+  type ToolkitWithDocsLink,
+} from "@/app/_lib/toolkit-slug";
+import {
+  getToolkitStaticParamsForCategory,
   INTEGRATION_CATEGORIES,
   listValidIntegrationLinks,
 } from "@/app/_lib/toolkit-static-params";
@@ -246,3 +251,98 @@ describe("hardcoded internal links in toolkit components resolve", () => {
     TIMEOUT
   );
 });
+
+// ---------------------------------------------------------------------------
+// Toolkit page canonical hygiene
+//
+// docs' only page-level <link rel="canonical"> comes from the generated toolkit
+// pages (toolkit-docs-page.tsx → generateMetadata, which emits
+// `/en/resources/integrations/<category>/<getToolkitSlug(data)>`). This guards
+// that canonical class — the docs analog of the www canonical guard, and
+// specifically the "Duplicate pages without canonical" finding MARTECH-19 fixed
+// (notion): every toolkit page's canonical points at its own URL, canonicals are
+// unique (no two pages share one), and none points at a redirect source or a
+// non-generated route. We re-derive the canonical with the same pure helpers the
+// page uses (static params + readToolkitData + getToolkitSlug) rather than
+// importing the page module, which pulls in browser-only render code.
+//
+// (The docs sitemap — app/sitemap.ts, static MDX pages only — is guarded in
+// tests/sitemap.test.ts: no redirect-source URLs, no duplicates.)
+// ---------------------------------------------------------------------------
+
+describe("toolkit page canonical hygiene", () => {
+  let canonicals: Array<{ page: string; canonical: string }>;
+  let validLinks: Set<string>;
+  let redirectSources: Set<string>;
+
+  beforeAll(async () => {
+    [validLinks, redirectSources] = await Promise.all([
+      listValidIntegrationLinks(),
+      readRedirectSources(),
+    ]);
+    canonicals = [];
+    for (const category of INTEGRATION_CATEGORIES) {
+      for (const { toolkitId } of await getToolkitStaticParamsForCategory(
+        category
+      )) {
+        const data = await readToolkitData(toolkitId);
+        const canonical = data
+          ? `${INTEGRATIONS}/${category}/${getToolkitSlug({
+              id: data.id,
+              docsLink: data.metadata?.docsLink,
+            })}`
+          : "";
+        canonicals.push({
+          page: `${INTEGRATIONS}/${category}/${toolkitId}`,
+          canonical,
+        });
+      }
+    }
+  }, TIMEOUT);
+
+  test("every generated toolkit page emits a canonical", () => {
+    expect(canonicals.length).toBeGreaterThan(0);
+    expect(canonicals.filter((c) => !c.canonical).map((c) => c.page)).toEqual(
+      []
+    );
+  });
+
+  test("each toolkit canonical points at the page's own URL", () => {
+    const mismatched = canonicals
+      .filter((c) => c.canonical && c.canonical !== c.page)
+      .map((c) => `${c.page} → ${c.canonical}`);
+    expect(mismatched).toEqual([]);
+  });
+
+  test("toolkit canonicals are unique (no duplicate-canonical pages)", () => {
+    const byCanonical = new Map<string, string>();
+    const duplicates: string[] = [];
+    for (const { page, canonical } of canonicals) {
+      if (!canonical) {
+        continue;
+      }
+      const prior = byCanonical.get(canonical);
+      if (prior) {
+        duplicates.push(`${canonical} ← ${prior} + ${page}`);
+      } else {
+        byCanonical.set(canonical, page);
+      }
+    }
+    expect(duplicates).toEqual([]);
+  });
+
+  test("no toolkit canonical points at a redirect or a missing route", () => {
+    const offenders: string[] = [];
+    for (const { canonical } of canonicals) {
+      if (!canonical) {
+        continue;
+      }
+      if (redirectSources.has(toLocaleParam(canonical))) {
+        offenders.push(`${canonical}: redirect source`);
+      } else if (!validLinks.has(withEnLocale(canonical))) {
+        offenders.push(`${canonical}: not a generated route`);
+      }
+    }
+    expect(offenders).toEqual([]);
+  });
+});