feat: cross-promo block in the credits purchase receipt email

lib/email.ts

@@ -1,4 +1,5 @@
 import { createEmailer, type Emailer } from "@profullstack/stack/email";
+import { promoBlock } from "@profullstack/cross-promo";
 import { env } from "./env";
 import type { SenderMailbox } from "./outreach/senderMailbox";
 
@@ -252,7 +253,14 @@ export function purchaseReceiptEmailHtml(input: {
   currency: string;
   paymentId: string;
   txHash?: string | null;
+  /** Cross-promo block (receiptPromo().html), shown after the receipt, above the footer. */
+  promoHtml?: string;
 }): string {
+  const promoRow = input.promoHtml
+    ? `<tr>
+            <td style="padding:0 32px 24px;">${input.promoHtml}</td>
+          </tr>`
+    : "";
   const txRow = input.txHash
     ? `<tr>
         <td style="padding:6px 0;color:#64748b;font-size:11px;text-transform:uppercase;letter-spacing:.1em;">Tx</td>
@@ -307,7 +315,8 @@ export function purchaseReceiptEmailHtml(input: {
                 A PDF copy of this receipt is attached for your records.
               </p>
             </td>
-          </tr>`;
+          </tr>
+          ${promoRow}`;
   return emailShell({
     title: `Your CrawlProof receipt`,
     innerHtml,
@@ -445,6 +454,24 @@ export async function sendMarketingEmail(input: {
   return { sent: true };
 }
 
+// The "more from the network" block for a credits buyer: a publisher. crawlproof.com is the
+// sender, so it never promotes itself. Themed to the dark email shell. Never throws.
+export function receiptPromo(to: string) {
+  return promoBlock({
+    site: "crawlproof.com",
+    audience: "publishers",
+    seed: to,
+    theme: {
+      accent: "#6ee7b7",
+      text: "#9aa3b2",
+      muted: "#64748b",
+      bg: "#0b0d10",
+      border: "#1f2630",
+      heading: "#e7e9ee",
+    },
+  });
+}
+
 export async function sendPurchaseReceiptEmail(input: {
   to: string;
   paymentId: string;
@@ -463,6 +490,7 @@ export async function sendPurchaseReceiptEmail(input: {
     minimumFractionDigits: input.amountCents % 100 === 0 ? 0 : 2,
   })}`;
   const filename = `crawlproof-receipt-${input.paymentId.slice(0, 12)}.pdf`;
+  const promo = await receiptPromo(input.to);
 
   const res = await c.send({
     from: env.resendFrom,
@@ -475,6 +503,7 @@ export async function sendPurchaseReceiptEmail(input: {
       currency: input.currency,
       paymentId: input.paymentId,
       txHash: input.txHash,
+      promoHtml: promo.html,
     }),
     attachments: [{ filename, content: input.pdf.toString("base64") }],
   });

package.json

@@ -33,6 +33,7 @@
     "@profullstack/autoblog": "^0.5.0",
     "@profullstack/coinpay": "^0.25.0",
     "@profullstack/coinpay-onboard": "^0.5.0",
+    "@profullstack/cross-promo": "^0.1.0",
     "@profullstack/fleetbar": "0.2.0",
     "@profullstack/footer": "latest",
     "@profullstack/hqtui": "^0.11.0",

tests/email-cross-promo.test.ts

@@ -0,0 +1,61 @@
+import { beforeAll, describe, expect, it, vi } from "vitest";
+
+// The cross-promo block reads its bundled catalog, never the CDN, in tests.
+process.env.CROSS_PROMO = "bundled";
+process.env.RESEND_API_KEY ||= "re_test";
+
+const sent: Array<{ to: string; subject: string; html: string }> = [];
+vi.mock("@profullstack/stack/email", () => ({
+  createEmailer: () => ({
+    send: vi.fn(async (m: { to: string; subject: string; html: string }) => {
+      sent.push(m);
+      return { sent: true };
+    }),
+  }),
+}));
+
+let email: typeof import("@/lib/email");
+beforeAll(async () => {
+  email = await import("@/lib/email");
+});
+
+describe("purchase receipt cross-promo", () => {
+  it("promotes publisher sites to a credits buyer, never crawlproof.com itself", async () => {
+    const promo = await email.receiptPromo("buyer@example.com");
+    expect(promo.items.length).toBeGreaterThan(0);
+    expect(promo.items.map((i) => i.id)).toContain("rssamplifier.com");
+    expect(promo.items.map((i) => i.id)).not.toContain("crawlproof.com");
+    expect(promo.html).not.toContain('href="https://crawlproof.com');
+    expect(promo.html).toContain("utm_source=crawlproof.com");
+  });
+
+  it("puts the block in the receipt after the billing link", async () => {
+    const res = await email.sendPurchaseReceiptEmail({
+      to: "buyer@example.com",
+      paymentId: "pay_1234567890abcdef",
+      packLabel: "Starter",
+      creditsAdded: 10,
+      amountCents: 1000,
+      currency: "USD",
+      completedAt: new Date().toISOString(),
+      pdf: Buffer.from("%PDF-1.4"),
+    });
+    expect(res.sent).toBe(true);
+    const html = sent.at(-1)!.html;
+    expect(html).toContain("Grow your readership");
+    expect(html).toContain("https://rssamp.com");
+    expect(html).not.toContain('href="https://crawlproof.com/?utm');
+    expect(html.indexOf("View billing")).toBeLessThan(html.indexOf("Grow your readership"));
+  });
+
+  it("renders the receipt unchanged without a promo", () => {
+    const html = email.purchaseReceiptEmailHtml({
+      packLabel: "Starter",
+      creditsAdded: 1,
+      amountFormatted: "$1",
+      currency: "USD",
+      paymentId: "pay_x",
+    });
+    expect(html).not.toContain("Grow your readership");
+  });
+});