diff --git a/services/platform-service/src/modules/promos/routes.test.ts b/services/platform-service/src/modules/promos/routes.test.ts
new file mode 100644
index 00000000..06d49ca9
--- /dev/null
+++ b/services/platform-service/src/modules/promos/routes.test.ts
@@ -0,0 +1,158 @@
+/**
+ * Route-level tests for promos module — Fastify inject with mocked Stripe.
+ */
+
+import Fastify from 'fastify';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+const stripeMock = {
+  promotionCodes: {
+    list: vi.fn(),
+    create: vi.fn(),
+    update: vi.fn(),
+  },
+  coupons: {
+    create: vi.fn(),
+  },
+};
+
+vi.mock('stripe', () => ({
+  default: vi.fn().mockImplementation(() => stripeMock),
+}));
+
+vi.mock('../../lib/request-context.js', () => ({
+  getRequestProductId: () => 'lysnrai',
+}));
+
+function buildPromo(overrides?: Partial<Record<string, unknown>>) {
+  return {
+    id: 'promo_1',
+    code: 'SAVE20',
+    active: true,
+    coupon: {
+      id: 'coupon_1',
+      percent_off: 20,
+      amount_off: null,
+      currency: 'usd',
+      duration: 'once',
+    },
+    times_redeemed: 0,
+    max_redemptions: null,
+    expires_at: null,
+    created: 1708000000,
+    metadata: { createdBy: 'admin', productId: 'lysnrai' },
+    ...overrides,
+  };
+}
+
+async function buildApp() {
+  const { promoRoutes } = await import('./routes.js');
+  const app = Fastify({ logger: false });
+  await app.register(promoRoutes, { prefix: '/api' });
+  return app;
+}
+
+describe('promoRoutes', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    process.env.STRIPE_SECRET_KEY = 'sk_test_123';
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('GET /promos lists promo codes', async () => {
+    stripeMock.promotionCodes.list.mockResolvedValue({ data: [buildPromo()] });
+    const app = await buildApp();
+
+    const res = await app.inject({ method: 'GET', url: '/api/promos?active=true' });
+
+    expect(res.statusCode).toBe(200);
+    const data = JSON.parse(res.body);
+    expect(data.promos).toHaveLength(1);
+    expect(data.promos[0].code).toBe('SAVE20');
+  });
+
+  it('POST /promos returns 400 when discount fields are missing', async () => {
+    const app = await buildApp();
+
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/promos',
+      payload: { code: 'bad', createdBy: 'admin' },
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
+
+  it('POST /promos creates coupon and promotion code', async () => {
+    stripeMock.coupons.create.mockResolvedValue({ id: 'coupon_1' });
+    stripeMock.promotionCodes.create.mockResolvedValue(buildPromo());
+    const app = await buildApp();
+
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/promos',
+      payload: {
+        code: 'save-20!',
+        percentOff: 20,
+        duration: 'once',
+        createdBy: 'admin',
+      },
+    });
+
+    expect(res.statusCode).toBe(201);
+    const data = JSON.parse(res.body);
+    expect(data.code).toBe('SAVE20');
+    expect(stripeMock.promotionCodes.create).toHaveBeenCalled();
+  });
+
+  it('POST /promos/validate returns 400 without code', async () => {
+    const app = await buildApp();
+
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/promos/validate',
+      payload: {},
+    });
+
+    expect(res.statusCode).toBe(400);
+  });
+
+  it('POST /promos/validate returns invalid when no active promo', async () => {
+    stripeMock.promotionCodes.list.mockResolvedValue({ data: [] });
+    const app = await buildApp();
+
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/promos/validate',
+      payload: { code: 'NOPE' },
+    });
+
+    expect(res.statusCode).toBe(200);
+    const data = JSON.parse(res.body);
+    expect(data.valid).toBe(false);
+    expect(data.promo).toBeNull();
+  });
+
+  it('PUT /promos/:id/deactivate deactivates promo', async () => {
+    stripeMock.promotionCodes.update.mockResolvedValue(buildPromo({ active: false }));
+    const app = await buildApp();
+
+    const res = await app.inject({ method: 'PUT', url: '/api/promos/promo_1/deactivate' });
+
+    expect(res.statusCode).toBe(200);
+    const data = JSON.parse(res.body);
+    expect(data.active).toBe(false);
+  });
+
+  it('PUT /promos/:id/deactivate returns 400 on Stripe error', async () => {
+    stripeMock.promotionCodes.update.mockRejectedValue(new Error('stripe failure'));
+    const app = await buildApp();
+
+    const res = await app.inject({ method: 'PUT', url: '/api/promos/promo_bad/deactivate' });
+
+    expect(res.statusCode).toBe(400);
+  });
+});