diff --git a/loop/plan.md b/loop/plan.md
index abcee85f..bae28a0c 100644
--- a/loop/plan.md
+++ b/loop/plan.md
@@ -22,7 +22,7 @@
 
 - [x] **TEST-03** — Create frontend unit tests: app store. Write `neode-ui/src/stores/__tests__/app.test.ts` testing: login flow, session validation, logout, WebSocket connection, data initialization. Use `createTestingPinia()`. Target: 6+ test cases. **Acceptance**: all tests pass.
 
-- [ ] **TEST-04** — Create frontend unit tests: container store. Write `neode-ui/src/stores/__tests__/container.test.ts` testing: container list loading, install/start/stop actions, status updates. Target: 5+ test cases. **Acceptance**: all tests pass.
+- [x] **TEST-04** — Create frontend unit tests: container store. Write `neode-ui/src/stores/__tests__/container.test.ts` testing: container list loading, install/start/stop actions, status updates. Target: 5+ test cases. **Acceptance**: all tests pass.
 
 - [ ] **TEST-05** — Create frontend unit tests: router guards. Write `neode-ui/src/router/__tests__/guards.test.ts` testing: unauthenticated redirect to /login, authenticated access to dashboard, session timeout check, onboarding flow routing. Target: 6+ test cases. **Acceptance**: all tests pass.
 
diff --git a/neode-ui/src/stores/__tests__/container.test.ts b/neode-ui/src/stores/__tests__/container.test.ts
new file mode 100644
index 00000000..6fae57c0
--- /dev/null
+++ b/neode-ui/src/stores/__tests__/container.test.ts
@@ -0,0 +1,131 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { setActivePinia, createPinia } from 'pinia'
+
+vi.mock('@/api/container-client', () => ({
+  containerClient: {
+    listContainers: vi.fn(),
+    getHealthStatus: vi.fn(),
+    installApp: vi.fn(),
+    startContainer: vi.fn(),
+    stopContainer: vi.fn(),
+    removeContainer: vi.fn(),
+    getContainerLogs: vi.fn(),
+    getContainerStatus: vi.fn(),
+    startBundledApp: vi.fn(),
+    stopBundledApp: vi.fn(),
+  },
+}))
+
+import { useContainerStore } from '../container'
+import { containerClient } from '@/api/container-client'
+
+const mockedClient = vi.mocked(containerClient)
+
+const mockContainers = [
+  { name: 'bitcoin-knots', state: 'running', status: 'Up 2 hours', image: 'bitcoinknots:29', lan_address: 'http://localhost:8332' },
+  { name: 'lnd', state: 'stopped', status: 'Exited (0)', image: 'lnd:v0.18.4', lan_address: undefined },
+  { name: 'mempool', state: 'running', status: 'Up 1 hour', image: 'mempool:latest', lan_address: 'http://localhost:8080' },
+]
+
+describe('useContainerStore', () => {
+  beforeEach(() => {
+    setActivePinia(createPinia())
+    vi.clearAllMocks()
+  })
+
+  it('fetchContainers loads container list', async () => {
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    const store = useContainerStore()
+
+    await store.fetchContainers()
+
+    expect(store.containers).toEqual(mockContainers)
+    expect(store.loading).toBe(false)
+    expect(store.error).toBeNull()
+  })
+
+  it('fetchContainers sets error on failure', async () => {
+    mockedClient.listContainers.mockRejectedValue(new Error('Connection refused'))
+    const store = useContainerStore()
+
+    await store.fetchContainers()
+
+    expect(store.error).toBe('Connection refused')
+    expect(store.loading).toBe(false)
+  })
+
+  it('runningContainers filters correctly', async () => {
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    const store = useContainerStore()
+
+    await store.fetchContainers()
+
+    expect(store.runningContainers).toHaveLength(2)
+    expect(store.runningContainers.map(c => c.name)).toEqual(['bitcoin-knots', 'mempool'])
+  })
+
+  it('stoppedContainers filters correctly', async () => {
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    const store = useContainerStore()
+
+    await store.fetchContainers()
+
+    expect(store.stoppedContainers).toHaveLength(1)
+    expect(store.stoppedContainers[0].name).toBe('lnd')
+  })
+
+  it('startContainer calls client and refreshes', async () => {
+    mockedClient.startContainer.mockResolvedValue(undefined)
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    mockedClient.getHealthStatus.mockResolvedValue({ 'bitcoin-knots': 'healthy' })
+    const store = useContainerStore()
+
+    await store.startContainer('bitcoin-knots')
+
+    expect(mockedClient.startContainer).toHaveBeenCalledWith('bitcoin-knots')
+    expect(mockedClient.listContainers).toHaveBeenCalled()
+    expect(mockedClient.getHealthStatus).toHaveBeenCalled()
+    expect(store.isAppLoading('bitcoin-knots')).toBe(false)
+  })
+
+  it('stopContainer calls client and refreshes', async () => {
+    mockedClient.stopContainer.mockResolvedValue(undefined)
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    const store = useContainerStore()
+
+    await store.stopContainer('lnd')
+
+    expect(mockedClient.stopContainer).toHaveBeenCalledWith('lnd')
+    expect(mockedClient.listContainers).toHaveBeenCalled()
+    expect(store.isAppLoading('lnd')).toBe(false)
+  })
+
+  it('getAppState returns correct states', async () => {
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    const store = useContainerStore()
+
+    await store.fetchContainers()
+
+    expect(store.getAppState('bitcoin-knots')).toBe('running')
+    expect(store.getAppState('lnd')).toBe('stopped')
+    expect(store.getAppState('nonexistent')).toBe('not-installed')
+  })
+
+  it('isAppLoading tracks per-app loading state', async () => {
+    let resolveStart: (() => void) | undefined
+    mockedClient.startContainer.mockImplementation(() => new Promise(r => { resolveStart = r }))
+    mockedClient.listContainers.mockResolvedValue(mockContainers)
+    mockedClient.getHealthStatus.mockResolvedValue({})
+    const store = useContainerStore()
+
+    const startPromise = store.startContainer('bitcoin-knots')
+
+    expect(store.isAppLoading('bitcoin-knots')).toBe(true)
+    expect(store.isAppLoading('lnd')).toBe(false)
+
+    resolveStart!()
+    await startPromise
+
+    expect(store.isAppLoading('bitcoin-knots')).toBe(false)
+  })
+})