diff --git a/test/ralph-loop.test.ts b/test/ralph-loop.test.ts
new file mode 100644
index 00000000..43d32281
--- /dev/null
+++ b/test/ralph-loop.test.ts
@@ -0,0 +1,383 @@
+/**
+ * @fileoverview Tests for RalphLoop autonomous task execution engine
+ *
+ * Tests the Ralph Loop orchestration including:
+ * - Lifecycle management (start, stop, pause, resume)
+ * - Task assignment to sessions
+ * - Stats tracking
+ */
+
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+
+// Use vi.hoisted to create mock state that can be accessed by both mocks and tests
+const mockState = vi.hoisted(() => ({
+  sessionManager: null as any,
+  taskQueue: null as any,
+  store: null as any,
+}));
+
+// Mock dependencies with factory functions that create fresh instances
+vi.mock('../src/session-manager.js', () => {
+  const { EventEmitter } = require('node:events');
+
+  class MockSessionManager extends EventEmitter {
+    sessions = new Map();
+    getSessionCount = vi.fn(() => this.sessions.size);
+    getIdleSessions = vi.fn(() => []);
+    getBusySessions = vi.fn(() => []);
+    getSession = vi.fn((id: string) => this.sessions.get(id));
+  }
+
+  const instance = new MockSessionManager();
+  mockState.sessionManager = instance;
+
+  return {
+    getSessionManager: vi.fn(() => instance),
+    SessionManager: MockSessionManager,
+  };
+});
+
+vi.mock('../src/task-queue.js', () => {
+  const { EventEmitter } = require('node:events');
+
+  class MockTaskQueue extends EventEmitter {
+    tasks: any[] = [];
+    next = vi.fn(() => this.tasks.find((t: any) => t.status === 'pending') || null);
+    getCount = vi.fn(() => ({
+      total: this.tasks.length,
+      pending: this.tasks.filter((t: any) => t.status === 'pending').length,
+      running: this.tasks.filter((t: any) => t.status === 'running').length,
+      completed: this.tasks.filter((t: any) => t.status === 'completed').length,
+      failed: this.tasks.filter((t: any) => t.status === 'failed').length,
+    }));
+    getTask = vi.fn((id: string) => this.tasks.find((t: any) => t.id === id));
+    updateTask = vi.fn();
+    addTask = vi.fn((options: any) => {
+      const task = { id: `task-${Date.now()}`, status: 'pending', ...options };
+      this.tasks.push(task);
+      return task;
+    });
+    getRunningTasks = vi.fn(() => this.tasks.filter((t: any) => t.status === 'running'));
+    getRunningTaskForSession = vi.fn();
+  }
+
+  const instance = new MockTaskQueue();
+  mockState.taskQueue = instance;
+
+  return {
+    getTaskQueue: vi.fn(() => instance),
+    TaskQueue: MockTaskQueue,
+  };
+});
+
+vi.mock('../src/state-store.js', () => {
+  class MockStateStore {
+    state: any = { ralphLoop: { status: 'stopped' }, tasks: {}, config: { pollIntervalMs: 1000 } };
+    getConfig = vi.fn(() => this.state.config);
+    getRalphLoopState = vi.fn(() => this.state.ralphLoop);
+    setRalphLoopState = vi.fn((update: any) => {
+      this.state.ralphLoop = { ...this.state.ralphLoop, ...update };
+    });
+    getTasks = vi.fn(() => this.state.tasks);
+    setTask = vi.fn();
+    removeTask = vi.fn();
+  }
+
+  const instance = new MockStateStore();
+  mockState.store = instance;
+
+  return {
+    getStore: vi.fn(() => instance),
+    StateStore: MockStateStore,
+  };
+});
+
+// Import after mocking
+import { RalphLoop, getRalphLoop } from '../src/ralph-loop.js';
+
+describe('RalphLoop', () => {
+  let loop: RalphLoop;
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+
+    // Reset mock state
+    if (mockState.sessionManager) {
+      mockState.sessionManager.sessions.clear();
+    }
+    if (mockState.taskQueue) {
+      mockState.taskQueue.tasks = [];
+    }
+    if (mockState.store) {
+      mockState.store.state = {
+        ralphLoop: { status: 'stopped' },
+        tasks: {},
+        config: { pollIntervalMs: 1000 },
+      };
+    }
+
+    // Reset mock functions
+    vi.clearAllMocks();
+
+    // Create fresh loop
+    loop = new RalphLoop({ pollIntervalMs: 100 });
+  });
+
+  afterEach(() => {
+    loop.stop();
+    vi.useRealTimers();
+  });
+
+  describe('initial state', () => {
+    it('should start in stopped status', () => {
+      expect(loop.status).toBe('stopped');
+      expect(loop.isRunning()).toBe(false);
+    });
+
+    it('should have zero elapsed time', () => {
+      expect(loop.getElapsedMs()).toBe(0);
+      expect(loop.getElapsedHours()).toBe(0);
+    });
+
+    it('should report min duration reached when no minimum set', () => {
+      expect(loop.isMinDurationReached()).toBe(true);
+    });
+  });
+
+  describe('start', () => {
+    it('should change status to running', async () => {
+      await loop.start();
+
+      expect(loop.status).toBe('running');
+      expect(loop.isRunning()).toBe(true);
+    });
+
+    it('should emit started event', async () => {
+      const handler = vi.fn();
+      loop.on('started', handler);
+
+      await loop.start();
+
+      expect(handler).toHaveBeenCalled();
+    });
+
+    it('should persist state to store', async () => {
+      await loop.start();
+
+      expect(mockState.store.setRalphLoopState).toHaveBeenCalledWith(
+        expect.objectContaining({
+          status: 'running',
+          tasksCompleted: 0,
+          tasksGenerated: 0,
+        })
+      );
+    });
+
+    it('should not start if already running', async () => {
+      await loop.start();
+      const handler = vi.fn();
+      loop.on('started', handler);
+
+      await loop.start();
+
+      expect(handler).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('stop', () => {
+    it('should change status to stopped', async () => {
+      await loop.start();
+
+      loop.stop();
+
+      expect(loop.status).toBe('stopped');
+      expect(loop.isRunning()).toBe(false);
+    });
+
+    it('should emit stopped event', async () => {
+      await loop.start();
+      const handler = vi.fn();
+      loop.on('stopped', handler);
+
+      loop.stop();
+
+      expect(handler).toHaveBeenCalled();
+    });
+
+    it('should not stop if already stopped', () => {
+      const handler = vi.fn();
+      loop.on('stopped', handler);
+
+      loop.stop();
+
+      expect(handler).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('pause and resume', () => {
+    it('should pause a running loop', async () => {
+      await loop.start();
+
+      loop.pause();
+
+      expect(loop.status).toBe('paused');
+    });
+
+    it('should not pause if not running', () => {
+      loop.pause();
+
+      expect(loop.status).toBe('stopped');
+    });
+
+    it('should resume a paused loop', async () => {
+      await loop.start();
+      loop.pause();
+
+      loop.resume();
+
+      expect(loop.status).toBe('running');
+    });
+
+    it('should not resume if not paused', async () => {
+      await loop.start();
+
+      loop.resume(); // Should have no effect since it's running, not paused
+
+      expect(loop.status).toBe('running');
+    });
+  });
+
+  describe('getElapsedMs and getElapsedHours', () => {
+    it('should track elapsed time', async () => {
+      await loop.start();
+
+      vi.advanceTimersByTime(3600000); // 1 hour
+
+      expect(loop.getElapsedMs()).toBe(3600000);
+      expect(loop.getElapsedHours()).toBe(1);
+    });
+  });
+
+  describe('isMinDurationReached', () => {
+    it('should return true when no minimum set', () => {
+      expect(loop.isMinDurationReached()).toBe(true);
+    });
+
+    it('should return false before minimum reached', async () => {
+      loop.setMinDuration(1); // 1 hour
+      await loop.start();
+
+      vi.advanceTimersByTime(1800000); // 30 minutes
+
+      expect(loop.isMinDurationReached()).toBe(false);
+    });
+
+    it('should return true after minimum reached', async () => {
+      loop.setMinDuration(1); // 1 hour
+      await loop.start();
+
+      vi.advanceTimersByTime(3600001); // Just over 1 hour
+
+      expect(loop.isMinDurationReached()).toBe(true);
+    });
+  });
+
+  describe('setMinDuration', () => {
+    it('should set minimum duration in hours', () => {
+      loop.setMinDuration(2); // 2 hours
+
+      expect(mockState.store.setRalphLoopState).toHaveBeenCalledWith({
+        minDurationMs: 7200000, // 2 hours in ms
+      });
+    });
+  });
+
+  describe('getStats', () => {
+    it('should return complete stats object', async () => {
+      const mockRunningTask = { id: '2', status: 'running', isTimedOut: () => false };
+      mockState.taskQueue.tasks = [
+        { id: '1', status: 'pending' },
+        mockRunningTask,
+        { id: '3', status: 'completed' },
+      ];
+      mockState.taskQueue.getRunningTasks.mockReturnValue([mockRunningTask]);
+
+      await loop.start();
+      vi.advanceTimersByTime(60000); // 1 minute
+
+      const stats = loop.getStats();
+
+      expect(stats.status).toBe('running');
+      expect(stats.elapsedMs).toBe(60000);
+      expect(stats.minDurationReached).toBe(true);
+      expect(stats.tasksCompleted).toBe(0);
+      expect(stats.tasksGenerated).toBe(0);
+      expect(stats.total).toBe(3);
+      expect(stats.pending).toBe(1);
+      expect(stats.running).toBe(1);
+      expect(stats.completed).toBe(1);
+    });
+  });
+
+  describe('automatic stopping', () => {
+    it('should stop when all tasks are done and min duration reached', async () => {
+      mockState.taskQueue.tasks = [];
+      mockState.taskQueue.getCount.mockReturnValue({
+        total: 0,
+        pending: 0,
+        running: 0,
+        completed: 0,
+        failed: 0,
+      });
+      mockState.taskQueue.getRunningTasks.mockReturnValue([]);
+
+      await loop.start();
+      // Need to advance timers and await for the tick to complete
+      await vi.advanceTimersByTimeAsync(100);
+
+      expect(loop.status).toBe('stopped');
+    });
+
+    it('should not stop if pending tasks exist', async () => {
+      mockState.taskQueue.tasks = [{ id: '1', status: 'pending' }];
+      mockState.taskQueue.getCount.mockReturnValue({
+        total: 1,
+        pending: 1,
+        running: 0,
+        completed: 0,
+        failed: 0,
+      });
+      mockState.taskQueue.getRunningTasks.mockReturnValue([]);
+
+      await loop.start();
+      await vi.advanceTimersByTimeAsync(100);
+
+      expect(loop.status).toBe('running');
+    });
+
+    it('should not stop if running tasks exist', async () => {
+      const mockTask = { id: '1', status: 'running', isTimedOut: () => false };
+      mockState.taskQueue.tasks = [mockTask];
+      mockState.taskQueue.getCount.mockReturnValue({
+        total: 1,
+        pending: 0,
+        running: 1,
+        completed: 0,
+        failed: 0,
+      });
+      mockState.taskQueue.getRunningTasks.mockReturnValue([mockTask]);
+
+      await loop.start();
+      await vi.advanceTimersByTimeAsync(100);
+
+      expect(loop.status).toBe('running');
+    });
+  });
+});
+
+describe('getRalphLoop singleton', () => {
+  it('should return a RalphLoop instance', () => {
+    const loop = getRalphLoop();
+    expect(loop).toBeInstanceOf(RalphLoop);
+  });
+});