diff --git a/__tests__/api/push-send.test.ts b/__tests__/api/push-send.test.ts
new file mode 100644
index 0000000..44bc616
--- /dev/null
+++ b/__tests__/api/push-send.test.ts
@@ -0,0 +1,75 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+vi.mock('server-only', () => ({}))
+
+const { mockSendPushToUser } = vi.hoisted(() => ({
+  mockSendPushToUser: vi.fn(),
+}))
+
+vi.mock('@/lib/push-server', () => ({
+  sendPushToUser: mockSendPushToUser,
+  enabled: true,
+}))
+
+vi.hoisted(() => {
+  process.env.INTERNAL_PUSH_SECRET = 'a-valid-secret-that-is-at-least-32-chars'
+})
+
+import { POST } from '@/app/api/internal/push/send/route'
+
+const VALID_BODY = {
+  userId: 'user-1',
+  payload: { title: 'Hello', body: 'World', url: '/dashboard' },
+}
+const SECRET = 'a-valid-secret-that-is-at-least-32-chars'
+
+function makeRequest(body: unknown, bearer?: string) {
+  return new Request('http://localhost/api/internal/push/send', {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/json',
+      ...(bearer !== undefined ? { Authorization: bearer } : {}),
+    },
+    body: JSON.stringify(body),
+  })
+}
+
+beforeEach(() => {
+  vi.clearAllMocks()
+  mockSendPushToUser.mockResolvedValue(undefined)
+})
+
+describe('POST /api/internal/push/send', () => {
+  it('returns 401 without authorization header', async () => {
+    const res = await POST(makeRequest(VALID_BODY))
+    expect(res.status).toBe(401)
+    expect(mockSendPushToUser).not.toHaveBeenCalled()
+  })
+
+  it('returns 401 with wrong bearer secret', async () => {
+    const res = await POST(makeRequest(VALID_BODY, 'Bearer wrong-secret'))
+    expect(res.status).toBe(401)
+  })
+
+  it('returns 422 with invalid body', async () => {
+    const res = await POST(makeRequest({ userId: '', payload: {} }, `Bearer ${SECRET}`))
+    expect(res.status).toBe(422)
+    expect(mockSendPushToUser).not.toHaveBeenCalled()
+  })
+
+  it('returns 204 and calls sendPushToUser on success', async () => {
+    const res = await POST(makeRequest(VALID_BODY, `Bearer ${SECRET}`))
+    expect(res.status).toBe(204)
+    expect(mockSendPushToUser).toHaveBeenCalledWith('user-1', VALID_BODY.payload)
+  })
+
+  it('returns 400 for invalid JSON', async () => {
+    const req = new Request('http://localhost/api/internal/push/send', {
+      method: 'POST',
+      headers: { Authorization: `Bearer ${SECRET}`, 'Content-Type': 'application/json' },
+      body: 'not-json',
+    })
+    const res = await POST(req)
+    expect(res.status).toBe(400)
+  })
+})
diff --git a/__tests__/lib/push-server.test.ts b/__tests__/lib/push-server.test.ts
index 7a9b75a..87af039 100644
--- a/__tests__/lib/push-server.test.ts
+++ b/__tests__/lib/push-server.test.ts
@@ -13,13 +13,11 @@ vi.mock('web-push', () => ({
   },
 }))
 
-vi.mock('@/lib/env', () => ({
-  env: {
-    NEXT_PUBLIC_VAPID_PUBLIC_KEY: 'pk',
-    VAPID_PRIVATE_KEY: 'sk',
-    VAPID_SUBJECT: 'mailto:test@example.com',
-  },
-}))
+vi.hoisted(() => {
+  process.env.NEXT_PUBLIC_VAPID_PUBLIC_KEY = 'pk'
+  process.env.VAPID_PRIVATE_KEY = 'sk'
+  process.env.VAPID_SUBJECT = 'mailto:test@example.com'
+})
 
 const { mockPushSubscription } = vi.hoisted(() => ({
   mockPushSubscription: {
diff --git a/app/api/internal/push/send/route.ts b/app/api/internal/push/send/route.ts
new file mode 100644
index 0000000..4891e59
--- /dev/null
+++ b/app/api/internal/push/send/route.ts
@@ -0,0 +1,48 @@
+import { timingSafeEqual } from 'crypto'
+import { z } from 'zod'
+import { sendPushToUser } from '@/lib/push-server'
+
+const schema = z.object({
+  userId: z.string().min(1),
+  payload: z.object({
+    title: z.string().max(80),
+    body: z.string().max(300),
+    url: z.string().startsWith('/').or(z.string().url()),
+    tag: z.string().optional(),
+  }),
+})
+
+export async function POST(req: Request) {
+  if (!process.env.INTERNAL_PUSH_SECRET) {
+    return new Response(null, { status: 503 })
+  }
+
+  const authHeader = req.headers.get('authorization') ?? ''
+  const expected = `Bearer ${process.env.INTERNAL_PUSH_SECRET}`
+  let authorized = false
+  try {
+    authorized =
+      authHeader.length === expected.length &&
+      timingSafeEqual(Buffer.from(authHeader), Buffer.from(expected))
+  } catch {
+    authorized = false
+  }
+  if (!authorized) {
+    return new Response(null, { status: 401 })
+  }
+
+  let body: unknown
+  try {
+    body = await req.json()
+  } catch {
+    return new Response(null, { status: 400 })
+  }
+
+  const parsed = schema.safeParse(body)
+  if (!parsed.success) {
+    return Response.json({ errors: parsed.error.flatten().fieldErrors }, { status: 422 })
+  }
+
+  await sendPushToUser(parsed.data.userId, parsed.data.payload)
+  return new Response(null, { status: 204 })
+}
diff --git a/lib/push-server.ts b/lib/push-server.ts
index 5e1ef59..5774253 100644
--- a/lib/push-server.ts
+++ b/lib/push-server.ts
@@ -2,7 +2,6 @@ import 'server-only'
 
 import webpush from 'web-push'
 import { prisma } from '@/lib/prisma'
-import { env } from '@/lib/env'
 
 export type PushPayload = {
   title: string
@@ -12,15 +11,15 @@ export type PushPayload = {
 }
 
 const vapidReady =
-  !!env.NEXT_PUBLIC_VAPID_PUBLIC_KEY &&
-  !!env.VAPID_PRIVATE_KEY &&
-  !!env.VAPID_SUBJECT
+  !!process.env.NEXT_PUBLIC_VAPID_PUBLIC_KEY &&
+  !!process.env.VAPID_PRIVATE_KEY &&
+  !!process.env.VAPID_SUBJECT
 
 if (vapidReady) {
   webpush.setVapidDetails(
-    env.VAPID_SUBJECT!,
-    env.NEXT_PUBLIC_VAPID_PUBLIC_KEY!,
-    env.VAPID_PRIVATE_KEY!,
+    process.env.VAPID_SUBJECT!,
+    process.env.NEXT_PUBLIC_VAPID_PUBLIC_KEY!,
+    process.env.VAPID_PRIVATE_KEY!,
   )
 }