diff --git a/src/__tests__/finance-api.test.js b/src/__tests__/finance-api.test.js
new file mode 100644
index 0000000..4bc41db
--- /dev/null
+++ b/src/__tests__/finance-api.test.js
@@ -0,0 +1,116 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+// Mock client module
+vi.mock('../api/client', () => {
+  return {
+    default: {
+      get: vi.fn(),
+      post: vi.fn(),
+      put: vi.fn(),
+      delete: vi.fn(),
+    }
+  }
+})
+
+import client from '../api/client'
+import { financeApi } from '../api/finance'
+
+beforeEach(() => {
+  vi.clearAllMocks()
+})
+
+describe('financeApi', () => {
+  // Categories
+  describe('categories', () => {
+    it('listCategories calls GET finance/categories', async () => {
+      const mockData = [{ id: 1, name: 'Еда', emoji: '🍔' }]
+      client.get.mockResolvedValue({ data: mockData })
+      const result = await financeApi.listCategories()
+      expect(client.get).toHaveBeenCalledWith('finance/categories')
+      expect(result).toEqual(mockData)
+    })
+
+    it('createCategory calls POST finance/categories', async () => {
+      const input = { name: 'Test', type: 'expense', emoji: '🧪' }
+      const mockData = { id: 1, ...input }
+      client.post.mockResolvedValue({ data: mockData })
+      const result = await financeApi.createCategory(input)
+      expect(client.post).toHaveBeenCalledWith('finance/categories', input)
+      expect(result).toEqual(mockData)
+    })
+
+    it('updateCategory calls PUT finance/categories/:id', async () => {
+      const data = { name: 'Updated' }
+      client.put.mockResolvedValue({ data: { id: 5, ...data } })
+      const result = await financeApi.updateCategory(5, data)
+      expect(client.put).toHaveBeenCalledWith('finance/categories/5', data)
+      expect(result.name).toBe('Updated')
+    })
+
+    it('deleteCategory calls DELETE finance/categories/:id', async () => {
+      client.delete.mockResolvedValue({})
+      await financeApi.deleteCategory(3)
+      expect(client.delete).toHaveBeenCalledWith('finance/categories/3')
+    })
+  })
+
+  // Transactions
+  describe('transactions', () => {
+    it('listTransactions calls GET with params', async () => {
+      const mockData = [{ id: 1, amount: 500 }]
+      client.get.mockResolvedValue({ data: mockData })
+      const params = { month: 3, year: 2026 }
+      const result = await financeApi.listTransactions(params)
+      expect(client.get).toHaveBeenCalledWith('finance/transactions', { params })
+      expect(result).toEqual(mockData)
+    })
+
+    it('listTransactions works without params', async () => {
+      client.get.mockResolvedValue({ data: [] })
+      const result = await financeApi.listTransactions()
+      expect(client.get).toHaveBeenCalledWith('finance/transactions', { params: {} })
+      expect(result).toEqual([])
+    })
+
+    it('createTransaction calls POST', async () => {
+      const input = { amount: 100, type: 'expense', category_id: 1, date: '2026-03-01' }
+      client.post.mockResolvedValue({ data: { id: 1, ...input } })
+      const result = await financeApi.createTransaction(input)
+      expect(client.post).toHaveBeenCalledWith('finance/transactions', input)
+      expect(result.amount).toBe(100)
+    })
+
+    it('updateTransaction calls PUT', async () => {
+      const data = { amount: 200 }
+      client.put.mockResolvedValue({ data: { id: 7, ...data } })
+      const result = await financeApi.updateTransaction(7, data)
+      expect(client.put).toHaveBeenCalledWith('finance/transactions/7', data)
+      expect(result.amount).toBe(200)
+    })
+
+    it('deleteTransaction calls DELETE', async () => {
+      client.delete.mockResolvedValue({})
+      await financeApi.deleteTransaction(10)
+      expect(client.delete).toHaveBeenCalledWith('finance/transactions/10')
+    })
+  })
+
+  // Summary & Analytics
+  describe('summary & analytics', () => {
+    it('getSummary calls GET with params', async () => {
+      const mockData = { balance: 5000, total_income: 10000, total_expense: 5000 }
+      client.get.mockResolvedValue({ data: mockData })
+      const result = await financeApi.getSummary({ month: 3, year: 2026 })
+      expect(client.get).toHaveBeenCalledWith('finance/summary', { params: { month: 3, year: 2026 } })
+      expect(result.balance).toBe(5000)
+    })
+
+    it('getAnalytics calls GET with params', async () => {
+      const mockData = { monthly_trend: [], avg_daily_expense: 500 }
+      client.get.mockResolvedValue({ data: mockData })
+      const result = await financeApi.getAnalytics({ months: 6 })
+      expect(client.get).toHaveBeenCalledWith('finance/analytics', { params: { months: 6 } })
+      expect(result.avg_daily_expense).toBe(500)
+    })
+  })
+})
diff --git a/src/__tests__/tracker.test.jsx b/src/__tests__/tracker.test.jsx
new file mode 100644
index 0000000..85bc0c5
--- /dev/null
+++ b/src/__tests__/tracker.test.jsx
@@ -0,0 +1,64 @@
+import { describe, it, expect, vi } from 'vitest'
+import { render, screen, fireEvent } from '@testing-library/react'
+import Tracker from '../pages/Tracker'
+
+// Mock child pages
+vi.mock('../pages/Habits', () => ({
+  default: ({ embedded }) => <div data-testid="habits">Habits {embedded ? 'embedded' : ''}</div>
+}))
+vi.mock('../pages/Tasks', () => ({
+  default: ({ embedded }) => <div data-testid="tasks">Tasks {embedded ? 'embedded' : ''}</div>
+}))
+vi.mock('../pages/Stats', () => ({
+  default: ({ embedded }) => <div data-testid="stats">Stats {embedded ? 'embedded' : ''}</div>
+}))
+vi.mock('../components/Navigation', () => ({
+  default: () => <nav data-testid="navigation">Nav</nav>
+}))
+
+describe('Tracker', () => {
+  it('renders header with title', () => {
+    render(<Tracker />)
+    expect(screen.getByText(/Трекер/)).toBeInTheDocument()
+  })
+
+  it('renders all three tab buttons', () => {
+    render(<Tracker />)
+    expect(screen.getByText(/Привычки/)).toBeInTheDocument()
+    expect(screen.getByText(/Задачи/)).toBeInTheDocument()
+    expect(screen.getByText(/Статистика/)).toBeInTheDocument()
+  })
+
+  it('shows Habits tab by default', () => {
+    render(<Tracker />)
+    expect(screen.getByTestId('habits')).toBeInTheDocument()
+    expect(screen.queryByTestId('tasks')).not.toBeInTheDocument()
+    expect(screen.queryByTestId('stats')).not.toBeInTheDocument()
+  })
+
+  it('switches to Tasks tab on click', () => {
+    render(<Tracker />)
+    fireEvent.click(screen.getByText(/Задачи/))
+    expect(screen.getByTestId('tasks')).toBeInTheDocument()
+    expect(screen.queryByTestId('habits')).not.toBeInTheDocument()
+  })
+
+  it('switches to Stats tab on click', () => {
+    render(<Tracker />)
+    fireEvent.click(screen.getByText(/Статистика/))
+    expect(screen.getByTestId('stats')).toBeInTheDocument()
+    expect(screen.queryByTestId('habits')).not.toBeInTheDocument()
+  })
+
+  it('switches back to Habits', () => {
+    render(<Tracker />)
+    fireEvent.click(screen.getByText(/Задачи/))
+    fireEvent.click(screen.getByText(/Привычки/))
+    expect(screen.getByTestId('habits')).toBeInTheDocument()
+  })
+
+  it('renders navigation', () => {
+    render(<Tracker />)
+    expect(screen.getByTestId('navigation')).toBeInTheDocument()
+  })
+})