diff --git a/src/routes/__tests__/billing.test.ts b/src/routes/__tests__/billing.test.ts
index 6a7ffc2..8392613 100644
--- a/src/routes/__tests__/billing.test.ts
+++ b/src/routes/__tests__/billing.test.ts
@@ -2,436 +2,349 @@ import { describe, it, expect, vi, beforeEach } from 'vitest'
 import request from 'supertest'
 import express from 'express'
 
-// Mock logger
+// Hoist mock functions so they're available in vi.mock factories
+const {
+  mockBillingPortalCreate,
+  mockCheckoutSessionsCreate,
+  mockCheckoutSessionsRetrieve,
+  mockSubscriptionsRetrieve,
+  mockWebhooksConstructEvent,
+  mockProductsSearch,
+  mockPricesList,
+  mockPricesCreate,
+  mockPricesRetrieve,
+  mockProductsCreate,
+  mockStripeInstance,
+} = vi.hoisted(() => {
+  const mockBillingPortalCreate = vi.fn()
+  const mockCheckoutSessionsCreate = vi.fn()
+  const mockCheckoutSessionsRetrieve = vi.fn()
+  const mockSubscriptionsRetrieve = vi.fn()
+  const mockWebhooksConstructEvent = vi.fn()
+  const mockProductsSearch = vi.fn()
+  const mockPricesList = vi.fn()
+  const mockPricesCreate = vi.fn()
+  const mockPricesRetrieve = vi.fn()
+  const mockProductsCreate = vi.fn()
+
+  const mockStripeInstance = {
+    billingPortal: { sessions: { create: mockBillingPortalCreate } },
+    checkout: { sessions: { create: mockCheckoutSessionsCreate, retrieve: mockCheckoutSessionsRetrieve } },
+    subscriptions: { retrieve: mockSubscriptionsRetrieve },
+    webhooks: { constructEvent: mockWebhooksConstructEvent },
+    products: { search: mockProductsSearch, create: mockProductsCreate },
+    prices: { list: mockPricesList, create: mockPricesCreate, retrieve: mockPricesRetrieve },
+  }
+
+  return {
+    mockBillingPortalCreate, mockCheckoutSessionsCreate, mockCheckoutSessionsRetrieve,
+    mockSubscriptionsRetrieve, mockWebhooksConstructEvent, mockProductsSearch,
+    mockPricesList, mockPricesCreate, mockPricesRetrieve, mockProductsCreate, mockStripeInstance,
+  }
+})
+
 vi.mock('../../services/logger.js', () => ({
   default: { info: vi.fn(), error: vi.fn() }
 }))
 
-// Mock DB functions
 vi.mock('../../services/keys.js', () => ({
+  getCustomerIdByEmail: vi.fn(),
+  getKeyByEmail: vi.fn(),
   createPaidKey: vi.fn(),
   downgradeByCustomer: vi.fn(),
   updateEmailByCustomer: vi.fn(),
-  getCustomerIdByEmail: vi.fn(),
-  getKeyByEmail: vi.fn()
 }))
 
-// Create mock Stripe methods with default returns so initPrices() at import time works
-const mockCheckoutCreate = vi.fn()
-const mockCheckoutRetrieve = vi.fn()
-const mockSubRetrieve = vi.fn()
-const mockConstructEvent = vi.fn()
-const mockBillingPortalCreate = vi.fn()
-const mockProductsSearch = vi.fn().mockResolvedValue({ data: [{ id: 'prod_test_123', name: 'test' }] })
-const mockPricesList = vi.fn().mockResolvedValue({ data: [{ id: 'price_test_123', unit_amount: 900 }] })
-const mockPricesCreate = vi.fn().mockResolvedValue({ id: 'price_new_123' })
-const mockProductsCreate = vi.fn().mockResolvedValue({ id: 'prod_new_123' })
-const mockPricesRetrieve = vi.fn()
-
-const mockStripe = {
-  checkout: { sessions: { create: mockCheckoutCreate, retrieve: mockCheckoutRetrieve } },
-  subscriptions: { retrieve: mockSubRetrieve },
-  webhooks: { constructEvent: mockConstructEvent },
-  billingPortal: { sessions: { create: mockBillingPortalCreate } },
-  products: { search: mockProductsSearch, create: mockProductsCreate },
-  prices: { list: mockPricesList, create: mockPricesCreate, retrieve: mockPricesRetrieve },
-}
-
 vi.mock('stripe', () => ({
-  default: vi.fn().mockImplementation(function() { return mockStripe })
+  default: function Stripe() { return mockStripeInstance },
 }))
 
-// Stub env BEFORE importing router
-vi.stubEnv('STRIPE_SECRET_KEY', 'sk_test_123456789')
-vi.stubEnv('STRIPE_WEBHOOK_SECRET', 'whsec_test_secret')
-vi.stubEnv('BASE_URL', 'https://test.snapapi.eu')
+// Set env vars BEFORE import (vi.stubEnv may not work for module-level reads)
+process.env.STRIPE_SECRET_KEY = 'sk_test_123456789'
+process.env.STRIPE_WEBHOOK_SECRET = 'whsec_test_secret'
+process.env.BASE_URL = 'https://test.snapapi.eu'
+
+// Setup default mocks for initPrices (runs on import) — prices not found, so create them
+mockProductsSearch.mockResolvedValue({ data: [{ id: 'prod_snap_test' }] })
+mockPricesList.mockImplementation(async () => ({ data: [] }))
+mockPricesCreate.mockImplementation(async ({ unit_amount }: any) => ({ id: `price_${unit_amount}` }))
 
-import { createPaidKey, downgradeByCustomer, updateEmailByCustomer, getCustomerIdByEmail, getKeyByEmail } from '../../services/keys.js'
 import { billingRouter } from '../billing.js'
+import { getCustomerIdByEmail, getKeyByEmail, createPaidKey, downgradeByCustomer, updateEmailByCustomer } from '../../services/keys.js'
 
 const app = express()
+app.use('/v1/billing/webhook', express.raw({ type: '*/*' }))
 app.use(express.json())
 app.use('/v1/billing', billingRouter)
 
-// Default mock returns for getOrCreatePrice chain
-function setupPriceMocks() {
-  mockProductsSearch.mockResolvedValue({
-    data: [{ id: 'prod_test_123', name: 'SnapAPI Starter' }]
-  })
-  mockPricesList.mockResolvedValue({
-    data: [{ id: 'price_test_123', unit_amount: 900 }]
-  })
-  mockPricesCreate.mockResolvedValue({ id: 'price_new_123' })
-  mockProductsCreate.mockResolvedValue({ id: 'prod_new_123' })
-}
+describe('POST /v1/billing/portal', () => {
+  beforeEach(() => { vi.clearAllMocks() })
 
-beforeEach(() => {
-  // Clear call history but keep implementations for mocks that need defaults
-  mockCheckoutCreate.mockClear()
-  mockCheckoutRetrieve.mockClear()
-  mockSubRetrieve.mockClear()
-  mockConstructEvent.mockClear()
-  mockBillingPortalCreate.mockClear()
-  vi.mocked(createPaidKey).mockClear()
-  vi.mocked(downgradeByCustomer).mockClear()
-  vi.mocked(updateEmailByCustomer).mockClear()
-  vi.mocked(getCustomerIdByEmail).mockClear()
-  vi.mocked(getKeyByEmail).mockClear()
-  // Re-setup price mocks (getOrCreatePrice needs these if cache is cold)
-  setupPriceMocks()
-})
+  it('should return portal URL when email has stripe customer ID', async () => {
+    vi.mocked(getCustomerIdByEmail).mockResolvedValue('cus_123456')
+    mockBillingPortalCreate.mockResolvedValue({ url: 'https://billing.stripe.com/p/session_123456' })
 
-// ─── POST /v1/billing/checkout ───
-
-describe('POST /v1/billing/checkout', () => {
-  it('returns 400 when plan is missing', async () => {
-    const res = await request(app).post('/v1/billing/checkout').send({})
-    expect(res.status).toBe(400)
-    expect(res.body.error).toMatch(/Invalid plan/)
-  })
-
-  it('returns 400 for invalid plan name', async () => {
-    const res = await request(app).post('/v1/billing/checkout').send({ plan: 'enterprise' })
-    expect(res.status).toBe(400)
-    expect(res.body.error).toMatch(/Invalid plan/)
-  })
-
-  it('returns checkout URL for valid starter plan', async () => {
-    mockCheckoutCreate.mockResolvedValue({ url: 'https://checkout.stripe.com/session_abc' })
-
-    const res = await request(app).post('/v1/billing/checkout').send({ plan: 'starter' })
-    expect(res.status).toBe(200)
-    expect(res.body.url).toBe('https://checkout.stripe.com/session_abc')
-    expect(mockCheckoutCreate).toHaveBeenCalledWith(
-      expect.objectContaining({
-        mode: 'subscription',
-        metadata: expect.objectContaining({ plan: 'starter', service: 'snapapi' }),
-      })
+    const response = await request(app).post('/v1/billing/portal').send({ email: 'user@example.com' })
+    expect(response.status).toBe(200)
+    expect(response.body).toEqual({ url: 'https://billing.stripe.com/p/session_123456' })
+    expect(getCustomerIdByEmail).toHaveBeenCalledWith('user@example.com')
+    expect(mockBillingPortalCreate).toHaveBeenCalledWith(
+      expect.objectContaining({ customer: 'cus_123456' })
     )
   })
 
-  it('returns checkout URL for pro plan', async () => {
-    mockCheckoutCreate.mockResolvedValue({ url: 'https://checkout.stripe.com/session_pro' })
-    const res = await request(app).post('/v1/billing/checkout').send({ plan: 'pro' })
-    expect(res.status).toBe(200)
-    expect(res.body.url).toBe('https://checkout.stripe.com/session_pro')
+  it('should return 404 when email has no stripe customer ID', async () => {
+    vi.mocked(getCustomerIdByEmail).mockResolvedValue(undefined)
+    const response = await request(app).post('/v1/billing/portal').send({ email: 'nonexistent@example.com' })
+    expect(response.status).toBe(404)
+    expect(response.body.error).toContain('No subscription found')
   })
 
-  it('returns checkout URL for business plan', async () => {
-    mockCheckoutCreate.mockResolvedValue({ url: 'https://checkout.stripe.com/session_biz' })
-    const res = await request(app).post('/v1/billing/checkout').send({ plan: 'business' })
-    expect(res.status).toBe(200)
-    expect(res.body.url).toBe('https://checkout.stripe.com/session_biz')
+  it('should return 400 when email is missing', async () => {
+    const response = await request(app).post('/v1/billing/portal').send({})
+    expect(response.status).toBe(400)
+    expect(response.body).toEqual({ error: 'Email address is required' })
   })
 
-  it('returns 500 on Stripe error', async () => {
-    mockCheckoutCreate.mockRejectedValue(new Error('Stripe down'))
-    const res = await request(app).post('/v1/billing/checkout').send({ plan: 'starter' })
-    expect(res.status).toBe(500)
-    expect(res.body.error).toMatch(/Failed to create checkout/)
+  it('should return 400 when email is empty string', async () => {
+    const response = await request(app).post('/v1/billing/portal').send({ email: '' })
+    expect(response.status).toBe(400)
+    expect(response.body).toEqual({ error: 'Email address is required' })
   })
 })
 
-// ─── GET /v1/billing/success ───
+describe('GET /v1/billing/recover', () => {
+  beforeEach(() => { vi.clearAllMocks() })
+
+  it('should return success message and masked key when email exists', async () => {
+    vi.mocked(getKeyByEmail).mockResolvedValue({
+      key: 'snap_abcd1234efgh5678ijkl9012', tier: 'pro', email: 'user@example.com',
+      createdAt: '2024-01-01T00:00:00Z', stripeCustomerId: 'cus_123456'
+    })
+    const response = await request(app).get('/v1/billing/recover').query({ email: 'user@example.com' })
+    expect(response.status).toBe(200)
+    expect(response.body.maskedKey).toBe('snap_abcd...9012')
+  })
+
+  it('should return success message when email does not exist (no info leak)', async () => {
+    vi.mocked(getKeyByEmail).mockResolvedValue(undefined)
+    const response = await request(app).get('/v1/billing/recover').query({ email: 'nonexistent@example.com' })
+    expect(response.status).toBe(200)
+    expect(response.body.message).toContain('If an account exists')
+    expect(response.body.maskedKey).toBeUndefined()
+  })
+
+  it('should return 400 when email is missing', async () => {
+    const response = await request(app).get('/v1/billing/recover')
+    expect(response.status).toBe(400)
+  })
+
+  it('should return 400 when email is empty string', async () => {
+    const response = await request(app).get('/v1/billing/recover').query({ email: '' })
+    expect(response.status).toBe(400)
+  })
+
+  it('should properly mask API keys with correct format', async () => {
+    vi.mocked(getKeyByEmail).mockResolvedValue({
+      key: 'snap_1234567890abcdef', tier: 'starter', email: 'user@example.com', createdAt: '2024-01-01T00:00:00Z'
+    })
+    const response = await request(app).get('/v1/billing/recover').query({ email: 'user@example.com' })
+    expect(response.body.maskedKey).toBe('snap_1234...cdef')
+  })
+})
+
+describe('POST /v1/billing/checkout', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockProductsSearch.mockResolvedValue({ data: [{ id: 'prod_snap_test' }] })
+    mockPricesList.mockResolvedValue({ data: [{ id: 'price_test', unit_amount: 900 }] })
+  })
+
+  it('should return 400 for missing plan', async () => {
+    const response = await request(app).post('/v1/billing/checkout').send({})
+    expect(response.status).toBe(400)
+    expect(response.body.error).toContain('Invalid plan')
+  })
+
+  it('should return 400 for invalid plan name', async () => {
+    const response = await request(app).post('/v1/billing/checkout').send({ plan: 'enterprise' })
+    expect(response.status).toBe(400)
+    expect(response.body.error).toContain('Invalid plan')
+  })
+
+  it('should return checkout URL for valid plan (starter)', async () => {
+    mockCheckoutSessionsCreate.mockResolvedValue({ url: 'https://checkout.stripe.com/session_abc' })
+    const response = await request(app).post('/v1/billing/checkout').send({ plan: 'starter' })
+    expect(response.status).toBe(200)
+    expect(response.body).toEqual({ url: 'https://checkout.stripe.com/session_abc' })
+    expect(mockCheckoutSessionsCreate).toHaveBeenCalledWith(expect.objectContaining({
+      mode: 'subscription',
+      metadata: { plan: 'starter', service: 'snapapi' },
+    }))
+  })
+
+  it('should return checkout URL for pro plan', async () => {
+    mockCheckoutSessionsCreate.mockResolvedValue({ url: 'https://checkout.stripe.com/pro' })
+    const response = await request(app).post('/v1/billing/checkout').send({ plan: 'pro' })
+    expect(response.status).toBe(200)
+    expect(response.body.url).toBe('https://checkout.stripe.com/pro')
+  })
+
+  it('should return checkout URL for business plan', async () => {
+    mockCheckoutSessionsCreate.mockResolvedValue({ url: 'https://checkout.stripe.com/biz' })
+    const response = await request(app).post('/v1/billing/checkout').send({ plan: 'business' })
+    expect(response.status).toBe(200)
+    expect(response.body.url).toBe('https://checkout.stripe.com/biz')
+  })
+
+  it('should return 500 on Stripe API error', async () => {
+    mockCheckoutSessionsCreate.mockRejectedValue(new Error('Stripe is down'))
+    const response = await request(app).post('/v1/billing/checkout').send({ plan: 'starter' })
+    expect(response.status).toBe(500)
+    expect(response.body.error).toContain('Failed to create checkout session')
+  })
+})
 
 describe('GET /v1/billing/success', () => {
-  it('returns 400 when session_id is missing', async () => {
-    const res = await request(app).get('/v1/billing/success')
-    expect(res.status).toBe(400)
-    expect(res.text).toMatch(/Missing session_id/)
+  beforeEach(() => { vi.clearAllMocks() })
+
+  it('should return 400 for missing session_id', async () => {
+    const response = await request(app).get('/v1/billing/success')
+    expect(response.status).toBe(400)
+    expect(response.text).toBe('Missing session_id')
   })
 
-  it('returns HTML with API key for valid session', async () => {
-    const uniqueSessionId = `cs_test_success_${Date.now()}`
-    mockCheckoutRetrieve.mockResolvedValue({
-      id: uniqueSessionId,
+  it('should return HTML with API key for valid session', async () => {
+    mockCheckoutSessionsRetrieve.mockResolvedValue({
+      id: 'cs_test_unique_success_1',
       customer_details: { email: 'buyer@example.com' },
-      customer: 'cus_buyer_123',
       metadata: { plan: 'pro' },
+      customer: 'cus_buyer_1',
     })
-    vi.mocked(createPaidKey).mockResolvedValue({
-      key: 'snap_testkey1234567890ab',
-      tier: 'pro',
-      email: 'buyer@example.com',
-      createdAt: new Date().toISOString(),
-    } as any)
+    vi.mocked(createPaidKey).mockResolvedValue({ key: 'snap_newkey123456' } as any)
 
-    const res = await request(app).get('/v1/billing/success').query({ session_id: uniqueSessionId })
-    expect(res.status).toBe(200)
-    expect(res.text).toContain('snap_testkey1234567890ab')
-    expect(res.text).toContain('Welcome to SnapAPI')
-    expect(res.text).toContain('Pro Plan')
-    expect(createPaidKey).toHaveBeenCalledWith('buyer@example.com', 'pro', 'cus_buyer_123')
+    const response = await request(app).get('/v1/billing/success').query({ session_id: 'cs_test_unique_success_1' })
+    expect(response.status).toBe(200)
+    expect(response.headers['content-type']).toMatch(/html/)
+    expect(response.text).toContain('snap_newkey123456')
+    expect(response.text).toContain('Welcome to SnapAPI')
+    expect(response.text).toContain('Pro Plan')
+    expect(createPaidKey).toHaveBeenCalledWith('buyer@example.com', 'pro', 'cus_buyer_1')
   })
 
-  it('shows dedup message for already-provisioned session', async () => {
-    const dupSessionId = `cs_test_dup_${Date.now()}`
-    // First call provisions
-    mockCheckoutRetrieve.mockResolvedValue({
-      id: dupSessionId,
-      customer_details: { email: 'dup@example.com' },
-      customer: 'cus_dup',
-      metadata: { plan: 'starter' },
+  it('should handle duplicate session_id (dedup via provisionedSessions)', async () => {
+    const sessionId = 'cs_test_dedup_unique_2'
+    mockCheckoutSessionsRetrieve.mockResolvedValue({
+      id: sessionId, customer_details: { email: 'dedup@example.com' },
+      metadata: { plan: 'starter' }, customer: 'cus_dedup',
     })
-    vi.mocked(createPaidKey).mockResolvedValue({ key: 'snap_dupkey123', tier: 'starter', email: 'dup@example.com', createdAt: '' } as any)
+    vi.mocked(createPaidKey).mockResolvedValue({ key: 'snap_first_key' } as any)
 
-    await request(app).get('/v1/billing/success').query({ session_id: dupSessionId })
-
-    // Second call with same ID
+    await request(app).get('/v1/billing/success').query({ session_id: sessionId })
     vi.mocked(createPaidKey).mockClear()
-    const res = await request(app).get('/v1/billing/success').query({ session_id: dupSessionId })
-    expect(res.status).toBe(200)
-    expect(res.text).toContain('already provisioned')
+    const response = await request(app).get('/v1/billing/success').query({ session_id: sessionId })
+    expect(response.status).toBe(200)
+    expect(response.text).toContain('already provisioned')
     expect(createPaidKey).not.toHaveBeenCalled()
   })
 
-  it('returns 500 on Stripe error', async () => {
-    mockCheckoutRetrieve.mockRejectedValue(new Error('Stripe error'))
-    const res = await request(app).get('/v1/billing/success').query({ session_id: 'cs_fail' })
-    expect(res.status).toBe(500)
-    expect(res.text).toMatch(/Something went wrong/)
+  it('should return 500 on Stripe API error', async () => {
+    mockCheckoutSessionsRetrieve.mockRejectedValue(new Error('Stripe error'))
+    const response = await request(app).get('/v1/billing/success').query({ session_id: 'cs_test_error_3' })
+    expect(response.status).toBe(500)
+    expect(response.text).toContain('Something went wrong')
   })
 })
 
-// ─── POST /v1/billing/portal ───
-
-describe('POST /v1/billing/portal', () => {
-  it('returns portal URL when email has Stripe customer ID', async () => {
-    vi.mocked(getCustomerIdByEmail).mockResolvedValue('cus_portal_123')
-    mockBillingPortalCreate.mockResolvedValue({ url: 'https://billing.stripe.com/p/session_portal' })
-
-    const res = await request(app).post('/v1/billing/portal').send({ email: 'user@example.com' })
-    expect(res.status).toBe(200)
-    expect(res.body.url).toBe('https://billing.stripe.com/p/session_portal')
-    expect(mockBillingPortalCreate).toHaveBeenCalledWith(
-      expect.objectContaining({ customer: 'cus_portal_123' })
-    )
-  })
-
-  it('returns 404 when email has no Stripe customer', async () => {
-    vi.mocked(getCustomerIdByEmail).mockResolvedValue(undefined)
-    const res = await request(app).post('/v1/billing/portal').send({ email: 'nobody@example.com' })
-    expect(res.status).toBe(404)
-    expect(res.body.error).toMatch(/No subscription found/)
-  })
-
-  it('returns 400 when email is missing', async () => {
-    const res = await request(app).post('/v1/billing/portal').send({})
-    expect(res.status).toBe(400)
-    expect(res.body.error).toMatch(/Email address is required/)
-  })
-
-  it('returns 400 when email is empty string', async () => {
-    const res = await request(app).post('/v1/billing/portal').send({ email: '' })
-    expect(res.status).toBe(400)
-    expect(res.body.error).toMatch(/Email address is required/)
-  })
-})
-
-// ─── GET /v1/billing/recover ───
-
-describe('GET /v1/billing/recover', () => {
-  it('returns masked key when email exists', async () => {
-    vi.mocked(getKeyByEmail).mockResolvedValue({
-      key: 'snap_abcd1234efgh5678ijkl9012',
-      tier: 'pro',
-      email: 'user@example.com',
-      createdAt: '2024-01-01T00:00:00Z',
-      stripeCustomerId: 'cus_123456'
-    } as any)
-
-    const res = await request(app).get('/v1/billing/recover').query({ email: 'user@example.com' })
-    expect(res.status).toBe(200)
-    expect(res.body.message).toMatch(/If an account exists/)
-    expect(res.body.maskedKey).toBe('snap_abcd...9012')
-  })
-
-  it('returns success message when email does not exist (no info leak)', async () => {
-    vi.mocked(getKeyByEmail).mockResolvedValue(undefined)
-    const res = await request(app).get('/v1/billing/recover').query({ email: 'nobody@example.com' })
-    expect(res.status).toBe(200)
-    expect(res.body.message).toMatch(/If an account exists/)
-    expect(res.body.maskedKey).toBeUndefined()
-  })
-
-  it('returns 400 when email is missing', async () => {
-    const res = await request(app).get('/v1/billing/recover')
-    expect(res.status).toBe(400)
-    expect(res.body.error).toMatch(/Email address is required/)
-  })
-
-  it('returns 400 when email is empty string', async () => {
-    const res = await request(app).get('/v1/billing/recover').query({ email: '' })
-    expect(res.status).toBe(400)
-    expect(res.body.error).toMatch(/Email address is required/)
-  })
-
-  it('properly masks API keys', async () => {
-    vi.mocked(getKeyByEmail).mockResolvedValue({
-      key: 'snap_1234567890abcdef',
-      tier: 'starter',
-      email: 'user@example.com',
-      createdAt: '2024-01-01T00:00:00Z'
-    } as any)
-
-    const res = await request(app).get('/v1/billing/recover').query({ email: 'user@example.com' })
-    expect(res.status).toBe(200)
-    expect(res.body.maskedKey).toBe('snap_1234...cdef')
-  })
-})
-
-// ─── POST /v1/billing/webhook ───
-
 describe('POST /v1/billing/webhook', () => {
-  it('returns 400 when stripe-signature is missing', async () => {
-    const res = await request(app).post('/v1/billing/webhook').send({})
-    expect(res.status).toBe(400)
-    expect(res.text).toMatch(/Missing signature/)
+  beforeEach(() => { vi.clearAllMocks() })
+
+  it('should return 400 for missing stripe-signature header', async () => {
+    const response = await request(app).post('/v1/billing/webhook').send(Buffer.from('{}'))
+    expect(response.status).toBe(400)
+    expect(response.text).toBe('Missing signature')
   })
 
-  it('returns 400 on invalid signature', async () => {
-    mockConstructEvent.mockImplementation(() => {
-      throw new Error('Invalid signature')
+  it('should handle checkout.session.completed — provisions key', async () => {
+    const sessionId = 'cs_webhook_unique_4'
+    mockWebhooksConstructEvent.mockReturnValue({
+      id: 'evt_1', type: 'checkout.session.completed',
+      data: { object: {
+        id: sessionId, customer_details: { email: 'webhook@example.com' },
+        metadata: { plan: 'pro' }, customer: 'cus_wh_1', subscription: 'sub_123',
+      }}
     })
+    mockSubscriptionsRetrieve.mockResolvedValue({
+      items: { data: [{ price: { product: 'prod_snap_test' } }] }
+    })
+    vi.mocked(createPaidKey).mockResolvedValue({ key: 'snap_wh_key' } as any)
 
-    const res = await request(app)
-      .post('/v1/billing/webhook')
-      .set('stripe-signature', 'bad_sig')
-      .send({})
-    expect(res.status).toBe(400)
-    expect(res.text).toMatch(/Webhook error/)
+    const response = await request(app)
+      .post('/v1/billing/webhook').set('stripe-signature', 'sig_valid').send(Buffer.from('{}'))
+    expect(response.status).toBe(200)
+    expect(response.body.received).toBe(true)
+    expect(createPaidKey).toHaveBeenCalledWith('webhook@example.com', 'pro', 'cus_wh_1')
   })
 
-  it('processes checkout.session.completed and provisions key', async () => {
-    const uniqueWebhookSession = `cs_webhook_${Date.now()}`
-    mockConstructEvent.mockReturnValue({
-      type: 'checkout.session.completed',
-      id: 'evt_checkout_1',
-      data: {
-        object: {
-          id: uniqueWebhookSession,
-          customer_details: { email: 'webhook@example.com' },
-          customer: 'cus_webhook_123',
-          metadata: { plan: 'pro' },
-          subscription: 'sub_123'
-        }
-      }
+  it('should handle customer.subscription.updated with canceled status — downgrades', async () => {
+    mockWebhooksConstructEvent.mockReturnValue({
+      id: 'evt_2', type: 'customer.subscription.updated',
+      data: { object: {
+        customer: 'cus_cancel_1', status: 'canceled',
+        items: { data: [{ price: { product: 'prod_snap_test' } }] },
+      }}
     })
-    // isSnapAPIEvent needs to resolve the subscription's product
-    mockSubRetrieve.mockResolvedValue({
-      items: {
-        data: [{
-          price: { product: { id: 'prod_test_123' } }
-        }]
-      }
-    })
-    vi.mocked(createPaidKey).mockResolvedValue({ key: 'snap_wh_key', tier: 'pro', email: 'webhook@example.com', createdAt: '' } as any)
-
-    const res = await request(app)
-      .post('/v1/billing/webhook')
-      .set('stripe-signature', 'valid_sig')
-      .send({})
-
-    expect(res.status).toBe(200)
-    expect(res.body.received).toBe(true)
-    expect(createPaidKey).toHaveBeenCalledWith('webhook@example.com', 'pro', 'cus_webhook_123')
+    const response = await request(app)
+      .post('/v1/billing/webhook').set('stripe-signature', 'sig_valid').send(Buffer.from('{}'))
+    expect(response.status).toBe(200)
+    expect(downgradeByCustomer).toHaveBeenCalledWith('cus_cancel_1')
   })
 
-  it('processes customer.subscription.deleted and downgrades', async () => {
-    mockConstructEvent.mockReturnValue({
-      type: 'customer.subscription.deleted',
-      id: 'evt_sub_del',
-      data: {
-        object: {
-          customer: 'cus_downgrade_123',
-          items: {
-            data: [{
-              price: { product: 'prod_test_123' }
-            }]
-          }
-        }
-      }
+  it('should handle customer.subscription.deleted — downgrades', async () => {
+    mockWebhooksConstructEvent.mockReturnValue({
+      id: 'evt_3', type: 'customer.subscription.deleted',
+      data: { object: {
+        customer: 'cus_delete_1',
+        items: { data: [{ price: { product: 'prod_snap_test' } }] },
+      }}
     })
-
-    const res = await request(app)
-      .post('/v1/billing/webhook')
-      .set('stripe-signature', 'valid_sig')
-      .send({})
-
-    expect(res.status).toBe(200)
-    expect(downgradeByCustomer).toHaveBeenCalledWith('cus_downgrade_123')
+    const response = await request(app)
+      .post('/v1/billing/webhook').set('stripe-signature', 'sig_valid').send(Buffer.from('{}'))
+    expect(response.status).toBe(200)
+    expect(downgradeByCustomer).toHaveBeenCalledWith('cus_delete_1')
   })
 
-  it('processes customer.updated and updates email', async () => {
-    mockConstructEvent.mockReturnValue({
-      type: 'customer.updated',
-      id: 'evt_cust_upd',
-      data: {
-        object: {
-          id: 'cus_email_update',
-          email: 'newemail@example.com'
-        }
-      }
+  it('should handle customer.updated — updates email', async () => {
+    mockWebhooksConstructEvent.mockReturnValue({
+      id: 'evt_4', type: 'customer.updated',
+      data: { object: { id: 'cus_email_update', email: 'newemail@example.com' } }
     })
-
-    const res = await request(app)
-      .post('/v1/billing/webhook')
-      .set('stripe-signature', 'valid_sig')
-      .send({})
-
-    expect(res.status).toBe(200)
+    const response = await request(app)
+      .post('/v1/billing/webhook').set('stripe-signature', 'sig_valid').send(Buffer.from('{}'))
+    expect(response.status).toBe(200)
     expect(updateEmailByCustomer).toHaveBeenCalledWith('cus_email_update', 'newemail@example.com')
   })
 
-  it('ignores non-SnapAPI events', async () => {
-    mockConstructEvent.mockReturnValue({
-      type: 'customer.subscription.deleted',
-      id: 'evt_other',
-      data: {
-        object: {
-          customer: 'cus_other',
-          items: {
-            data: [{
-              price: { product: 'prod_DOCFAST_OTHER' }
-            }]
-          }
-        }
-      }
+  it('should ignore non-SnapAPI events (different product ID)', async () => {
+    mockWebhooksConstructEvent.mockReturnValue({
+      id: 'evt_5', type: 'customer.subscription.updated',
+      data: { object: {
+        customer: 'cus_other', status: 'canceled',
+        items: { data: [{ price: { product: 'prod_OTHER_not_snapapi' } }] },
+      }}
     })
-
-    const res = await request(app)
-      .post('/v1/billing/webhook')
-      .set('stripe-signature', 'valid_sig')
-      .send({})
-
-    expect(res.status).toBe(200)
-    expect(res.body.ignored).toBe(true)
+    const response = await request(app)
+      .post('/v1/billing/webhook').set('stripe-signature', 'sig_valid').send(Buffer.from('{}'))
+    expect(response.status).toBe(200)
+    expect(response.body).toEqual({ received: true, ignored: true })
     expect(downgradeByCustomer).not.toHaveBeenCalled()
   })
 
-  it('processes subscription.updated with canceled status', async () => {
-    mockConstructEvent.mockReturnValue({
-      type: 'customer.subscription.updated',
-      id: 'evt_sub_cancel',
-      data: {
-        object: {
-          customer: 'cus_cancel_123',
-          status: 'canceled',
-          items: {
-            data: [{
-              price: { product: 'prod_test_123' }
-            }]
-          }
-        }
-      }
-    })
-
-    const res = await request(app)
-      .post('/v1/billing/webhook')
-      .set('stripe-signature', 'valid_sig')
-      .send({})
-
-    expect(res.status).toBe(200)
-    expect(downgradeByCustomer).toHaveBeenCalledWith('cus_cancel_123')
+  it('should return 400 for invalid signature', async () => {
+    mockWebhooksConstructEvent.mockImplementation(() => { throw new Error('Invalid signature') })
+    const response = await request(app)
+      .post('/v1/billing/webhook').set('stripe-signature', 'sig_invalid').send(Buffer.from('{}'))
+    expect(response.status).toBe(400)
+    expect(response.text).toContain('Webhook error')
   })
 })