diff --git a/apps/website/.env.example b/apps/website/.env.example
index c6957548a..4449b83c5 100644
--- a/apps/website/.env.example
+++ b/apps/website/.env.example
@@ -12,3 +12,6 @@ RESEND_API_KEY=re_xxxxxxxxxxxxxxxxxxxxxxxxxxxx
 RESEND_AUDIENCE_ID=aud_xxxxxxxxxxxxxxxxxxxxxxxxxxxx
 RESEND_FROM="Angular Stream Resource <hello@cacheplane.io>"
 RESEND_NOTIFY_TO=hello@cacheplane.io
+
+# Loops.so (https://loops.so — free tier: 1,000 contacts)
+LOOPS_API_KEY=
diff --git a/apps/website/lib/loops.ts b/apps/website/lib/loops.ts
new file mode 100644
index 000000000..f259d1dab
--- /dev/null
+++ b/apps/website/lib/loops.ts
@@ -0,0 +1,60 @@
+const LOOPS_API_KEY = process.env.LOOPS_API_KEY || '';
+const LOOPS_BASE = 'https://app.loops.so/api/v1';
+
+/** Create or update a contact in Loops. Fails silently. */
+export async function loopsUpsertContact(opts: {
+  email: string;
+  firstName?: string;
+  source?: string;
+  properties?: Record<string, string | number | boolean>;
+}) {
+  if (!LOOPS_API_KEY) {
+    console.info('[loops] skipped (no API key):', opts.email);
+    return;
+  }
+  try {
+    const body: Record<string, unknown> = {
+      email: opts.email,
+      source: opts.source || 'website',
+      subscribed: true,
+    };
+    if (opts.firstName) body.firstName = opts.firstName;
+    if (opts.properties) Object.assign(body, opts.properties);
+
+    await fetch(`${LOOPS_BASE}/contacts/update`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${LOOPS_API_KEY}`,
+      },
+      body: JSON.stringify(body),
+    });
+  } catch (err) {
+    console.error('[loops] upsertContact failed:', err);
+  }
+}
+
+/** Send an event to trigger a Loops workflow. Fails silently. */
+export async function loopsSendEvent(opts: {
+  email: string;
+  eventName: string;
+  properties?: Record<string, string | number | boolean>;
+}) {
+  if (!LOOPS_API_KEY) return;
+  try {
+    await fetch(`${LOOPS_BASE}/events/send`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${LOOPS_API_KEY}`,
+      },
+      body: JSON.stringify({
+        email: opts.email,
+        eventName: opts.eventName,
+        ...(opts.properties ? { eventProperties: opts.properties } : {}),
+      }),
+    });
+  } catch (err) {
+    console.error('[loops] sendEvent failed:', err);
+  }
+}
diff --git a/apps/website/src/app/api/leads/route.ts b/apps/website/src/app/api/leads/route.ts
index 50ef6bb70..769f704d1 100644
--- a/apps/website/src/app/api/leads/route.ts
+++ b/apps/website/src/app/api/leads/route.ts
@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from 'next/server';
 import fs from 'fs';
 import path from 'path';
 import { sendEmail, FROM, NOTIFY_TO, addToAudience } from '../../../../lib/resend';
+import { loopsUpsertContact, loopsSendEvent } from '../../../../lib/loops';
 import { leadNotificationHtml } from '../../../../emails/lead-notification';
 
 const LEADS_FILE = path.join(process.cwd(), 'data', 'leads.ndjson');
@@ -40,6 +41,17 @@ export async function POST(req: NextRequest) {
         html: leadNotificationHtml({ name, email, company, message, ts }),
       }),
       addToAudience(email, name),
+      loopsUpsertContact({
+        email,
+        firstName: name,
+        source: 'lead-form',
+        properties: { company },
+      }),
+      loopsSendEvent({
+        email,
+        eventName: 'lead_submitted',
+        properties: { company },
+      }),
     ]);
   } catch (err) {
     console.error('[resend] lead notification failed:', err);
diff --git a/apps/website/src/app/api/newsletter/route.ts b/apps/website/src/app/api/newsletter/route.ts
index dda0e469d..bffda780e 100644
--- a/apps/website/src/app/api/newsletter/route.ts
+++ b/apps/website/src/app/api/newsletter/route.ts
@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { sendEmail, FROM, addToAudience } from '../../../../lib/resend';
+import { loopsUpsertContact, loopsSendEvent } from '../../../../lib/loops';
 import { newsletterWelcomeHtml } from '../../../../emails/newsletter-welcome';
 
 export async function POST(req: NextRequest) {
@@ -26,6 +27,14 @@ export async function POST(req: NextRequest) {
         html: newsletterWelcomeHtml(),
       }),
       addToAudience(email),
+      loopsUpsertContact({
+        email,
+        source: 'newsletter',
+      }),
+      loopsSendEvent({
+        email,
+        eventName: 'newsletter_subscribed',
+      }),
     ]);
   } catch (err) {
     console.error('[resend] newsletter signup failed:', err);
diff --git a/apps/website/src/app/api/whitepaper-signup/route.ts b/apps/website/src/app/api/whitepaper-signup/route.ts
index 89b12f227..172166b77 100644
--- a/apps/website/src/app/api/whitepaper-signup/route.ts
+++ b/apps/website/src/app/api/whitepaper-signup/route.ts
@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from 'next/server';
 import fs from 'fs';
 import path from 'path';
 import { sendEmail, FROM, addToAudience } from '../../../../lib/resend';
+import { loopsUpsertContact, loopsSendEvent } from '../../../../lib/loops';
 import { whitepaperDownloadHtml } from '../../../../emails/whitepaper-download';
 
 const SIGNUPS_FILE = path.join(process.cwd(), 'data', 'whitepaper-signups.ndjson');
@@ -39,6 +40,15 @@ export async function POST(req: NextRequest) {
         html: whitepaperDownloadHtml(name || undefined),
       }),
       addToAudience(email, name || undefined),
+      loopsUpsertContact({
+        email,
+        firstName: name || undefined,
+        source: 'whitepaper',
+      }),
+      loopsSendEvent({
+        email,
+        eventName: 'whitepaper_downloaded',
+      }),
     ]);
   } catch (err) {
     console.error('[resend] whitepaper email failed:', err);