diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..fd91464
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,17 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+      - run: python -m pip install --upgrade pip
+      - run: pip install -r requirements-dev.txt
+      - run: pytest
diff --git a/Makefile b/Makefile
index 3019bb6..5ac1ddf 100644
--- a/Makefile
+++ b/Makefile
@@ -60,7 +60,10 @@ run-enhanced:
 	$(ACT); OMP_NUM_THREADS=$(LLAMA_THREADS) $(PY) src/macbot/voice_assistant.py
 
 run-orchestrator:
-	$(ACT); $(PY) src/macbot/orchestrator.py
+        $(ACT); $(PY) src/macbot/orchestrator.py
+
+test:
+        $(ACT); pytest
 
 clean:
-	rm -rf $(VENV) $(WHISPER_DIR) $(LLAMA_DIR) __pycache__ */__pycache__
+        rm -rf $(VENV) $(WHISPER_DIR) $(LLAMA_DIR) __pycache__ */__pycache__
diff --git a/tests/test_interruptible_conversation.py b/tests/test_interruptible_conversation.py
index c462e3e..5787794 100644
--- a/tests/test_interruptible_conversation.py
+++ b/tests/test_interruptible_conversation.py
@@ -1,142 +1,68 @@
-#!/usr/bin/env python3
-"""
-Test script for interruptible conversation system
-"""
-
-import sys
 import os
+import sys
+import time
+import threading
+import numpy as np
+import pytest
+import types
+
+# Ensure the package can be imported without installation
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'src'))
 
+# Provide stub modules for optional audio dependencies
+sys.modules.setdefault('sounddevice', types.SimpleNamespace(OutputStream=object))
+sys.modules.setdefault('soundfile', types.SimpleNamespace())
+
 from macbot.audio_interrupt import AudioInterruptHandler
-from macbot.conversation_manager import ConversationManager, ConversationState
-import numpy as np
-import time
+from macbot.conversation_manager import ConversationManager, ConversationState, ResponseState
 
-def test_audio_interruption():
-    """Test basic audio interruption functionality"""
-    print("🧪 Testing Audio Interruption System...")
 
-    # Create audio handler
+
+def test_audio_interruption(monkeypatch):
+    """Audio playback can be interrupted."""
     handler = AudioInterruptHandler(sample_rate=24000)
 
-    # Generate test audio (1 second of 440Hz sine wave)
-    duration = 1.0
-    frequency = 440.0
-    t = np.linspace(0, duration, int(24000 * duration), False)
-    audio = np.sin(frequency * 2 * np.pi * t).astype(np.float32)
+    def fake_worker(self):
+        while self.is_playing and not self.interrupt_requested:
+            time.sleep(0.01)
+        self.is_playing = False
 
-    print("▶️  Playing test audio...")
-    success = handler.play_audio(audio)
-    print(f"✅ Audio playback {'completed' if success else 'was interrupted'}")
+    monkeypatch.setattr(AudioInterruptHandler, '_playback_worker', fake_worker)
+    audio = np.zeros(2400, dtype=np.float32)
+    result = {}
 
-    return success
+    def run_play():
+        result['completed'] = handler.play_audio(audio)
 
-def test_conversation_manager():
-    """Test conversation state management"""
-    print("\n🧪 Testing Conversation Manager...")
+    t = threading.Thread(target=run_play)
+    t.start()
+    time.sleep(0.05)
+    handler.interrupt_playback()
+    t.join()
 
-    manager = ConversationManager()
+    assert result['completed'] is False
+    status = handler.get_playback_status()
+    assert not status['is_playing']
+    assert status['interrupt_requested']
 
-    # Test state transitions
-    print("📝 Testing conversation states...")
 
-    # Start conversation
+def test_conversation_state_transitions():
+    """Conversation manager handles state transitions and buffering."""
+    manager = ConversationManager()
+    manager.lock = threading.RLock()
     conv_id = manager.start_conversation()
-    print(f"📊 Started conversation: {conv_id}")
-
-    # Add user input
-    manager.add_user_input("Hello MacBot")
-    print("📝 Added user input")
+    assert manager.current_context.conversation_id == conv_id
 
-    # Start response
-    manager.start_response()
-    print("🎤 Started response")
+    manager.add_user_input('Hello')
+    manager.start_response('Hi there')
+    assert manager.current_context.current_state == ConversationState.SPEAKING
 
-    # Simulate interruption
     manager.interrupt_response()
-    print("⏹️  Interrupted response")
+    assert manager.current_context.current_state == ConversationState.INTERRUPTED
 
-    # Check if we can resume
     buffered = manager.resume_response()
-    print(f"📊 Buffered response available: {buffered is not None}")
+    assert buffered == 'Hi there'
 
-    # Complete response
     manager.complete_response()
-    print("✅ Completed response")
-
-    # Check history
-    history = manager.get_recent_history()
-    print(f"📚 Conversation history: {len(history)} messages")
-
-    return len(history) > 0
-
-def test_integration():
-    """Test integrated audio interruption with conversation management"""
-    print("\n🧪 Testing Integrated System...")
-
-    # Create components
-    audio_handler = AudioInterruptHandler(sample_rate=24000)
-    conversation_manager = ConversationManager()
-
-    # Register callback
-    def on_state_change(context):
-        print(f"🔄 State changed to: {context.current_state.value}")
-        if context.current_state == ConversationState.INTERRUPTED:
-            audio_handler.interrupt_playback()
-
-    conversation_manager.register_state_callback(on_state_change)
-
-    # Generate longer test audio (3 seconds)
-    duration = 3.0
-    frequency = 440.0
-    t = np.linspace(0, duration, int(24000 * duration), False)
-    audio = np.sin(frequency * 2 * np.pi * t).astype(np.float32)
-
-    print("▶️  Starting integrated test...")
-
-    # Start conversation
-    conv_id = conversation_manager.start_conversation()
-    conversation_manager.add_user_input("Test message")
-    conversation_manager.start_response()
-
-    # Play audio (should complete normally)
-    success = audio_handler.play_audio(audio)
-
-    # Complete response
-    conversation_manager.complete_response()
-
-    print(f"✅ Integrated test {'completed successfully' if success else 'was interrupted'}")
-
-    return success
-
-def main():
-    """Run all tests"""
-    print("🚀 MacBot Interruptible Conversation System Test Suite")
-    print("=" * 60)
-
-    try:
-        # Test individual components
-        audio_test = test_audio_interruption()
-        conv_test = test_conversation_manager()
-        integration_test = test_integration()
-
-        # Summary
-        print("\n" + "=" * 60)
-        print("📊 Test Results:")
-        print(f"   Audio Interruption: {'✅ PASS' if audio_test else '❌ FAIL'}")
-        print(f"   Conversation Manager: {'✅ PASS' if conv_test else '❌ FAIL'}")
-        print(f"   Integration Test: {'✅ PASS' if integration_test else '❌ FAIL'}")
-
-        all_passed = audio_test and conv_test and integration_test
-        print(f"\n🎯 Overall: {'✅ ALL TESTS PASSED' if all_passed else '❌ SOME TESTS FAILED'}")
-
-        return 0 if all_passed else 1
-
-    except Exception as e:
-        print(f"❌ Test suite failed with error: {e}")
-        import traceback
-        traceback.print_exc()
-        return 1
-
-if __name__ == "__main__":
-    sys.exit(main())
+    assert manager.current_context.current_state == ConversationState.IDLE
+    assert len(manager.get_recent_history()) == 2
diff --git a/tests/test_message_bus.py b/tests/test_message_bus.py
index 6f13cfd..ba926f0 100644
--- a/tests/test_message_bus.py
+++ b/tests/test_message_bus.py
@@ -1,71 +1,63 @@
-#!/usr/bin/env python3
-"""
-Test script for MacBot Message Bus System
-"""
-import sys
 import os
+import sys
 import time
+import pytest
+
+# Ensure the package can be imported without installation
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'src'))
 
-from macbot.message_bus import MessageBus, start_message_bus, stop_message_bus
+from macbot.message_bus import start_message_bus, stop_message_bus
+import macbot.message_bus_client as mb_client
 from macbot.message_bus_client import MessageBusClient
 
-def test_message_bus():
-    """Test the message bus system"""
-    print("🧪 Testing MacBot Message Bus System...")
 
-    # Start message bus
-    print("1. Starting message bus server...")
+@pytest.fixture
+def message_bus():
     bus = start_message_bus(host='localhost', port=8082)
-
-    # Create test clients
-    print("2. Creating test clients...")
-    client1 = MessageBusClient(
-        host='localhost',
-        port=8082,
-        service_type='test_service_1'
-    )
-    client2 = MessageBusClient(
-        host='localhost',
-        port=8082,
-        service_type='test_service_2'
-    )
-
-    # Start clients
-    print("3. Starting clients...")
-    client1.start()
-    client2.start()
-
-    # Wait for connections
-    time.sleep(3)
-
-    # Test message sending
-    print("4. Testing message exchange...")
-
-    # Client 1 sends message
-    client1.send_message({
-        'type': 'test_message',
-        'content': 'Hello from client 1!',
-        'timestamp': time.time()
-    })
-
-    # Client 2 sends message
-    client2.send_message({
-        'type': 'test_message',
-        'content': 'Hello from client 2!',
-        'timestamp': time.time()
-    })
-
-    # Wait for messages to be processed
-    time.sleep(2)
-
-    print("5. Test completed successfully!")
-    print("✅ Message bus system is working properly")
-
-    # Cleanup
-    client1.stop()
-    client2.stop()
+    mb_client.message_bus = bus
+    yield bus
     stop_message_bus()
 
-if __name__ == "__main__":
-    test_message_bus()
+
+@pytest.fixture
+def create_client(message_bus):
+    clients = []
+
+    def _factory(service_type: str):
+        client = MessageBusClient(host='localhost', port=8082, service_type=service_type)
+        client.start()
+        clients.append(client)
+        time.sleep(0.1)  # allow connection
+        return client
+
+    yield _factory
+
+    for c in clients:
+        c.stop()
+
+
+def test_message_delivery(create_client):
+    """Clients should receive messages sent on the bus."""
+    received = []
+
+    client2 = create_client('service2')
+    client2.register_handler('test', lambda m: received.append(m))
+
+    client1 = create_client('service1')
+    client1.send_message({'type': 'test', 'content': 'hello'})
+
+    timeout = time.time() + 2
+    while not received and time.time() < timeout:
+        time.sleep(0.05)
+
+    assert received and received[0]['content'] == 'hello'
+
+
+def test_service_status(message_bus, create_client):
+    """Message bus should track registered services."""
+    client = create_client('network_service')
+    time.sleep(0.1)
+    status = message_bus.get_service_status()
+    assert 'network_service' in status
+    assert status['network_service']['count'] == 1
+    assert client.client_id in status['network_service']['clients']
diff --git a/tests/test_tool_calling.py b/tests/test_tool_calling.py
new file mode 100644
index 0000000..34c7ffa
--- /dev/null
+++ b/tests/test_tool_calling.py
@@ -0,0 +1,40 @@
+import os
+import sys
+import pytest
+import types
+
+# Ensure package import without installation
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+# Provide stubs for optional dependencies used by voice_assistant
+sys.modules.setdefault('sounddevice', types.SimpleNamespace())
+sys.modules.setdefault('soundfile', types.SimpleNamespace())
+sys.modules.setdefault('psutil', types.SimpleNamespace())
+sys.modules.setdefault('requests', types.SimpleNamespace(get=lambda *a, **k: None, post=lambda *a, **k: None))
+
+from macbot.voice_assistant import ToolCaller, tools
+
+
+def test_tool_caller_web_search(monkeypatch):
+    caller = ToolCaller()
+    called = {}
+
+    def fake_search(query):
+        called['query'] = query
+        return 'ok'
+
+    monkeypatch.setattr(tools, 'web_search', fake_search)
+    result = caller.web_search('python')
+    assert result == 'ok'
+    assert called['query'] == 'python'
+
+
+def test_tool_caller_error_handling(monkeypatch):
+    caller = ToolCaller()
+
+    def boom(query):
+        raise RuntimeError('fail')
+
+    monkeypatch.setattr(tools, 'web_search', boom)
+    result = caller.web_search('python')
+    assert "couldn't perform" in result.lower()
diff --git a/tests/test_tts_streaming.py b/tests/test_tts_streaming.py
new file mode 100644
index 0000000..a6d9dc4
--- /dev/null
+++ b/tests/test_tts_streaming.py
@@ -0,0 +1,27 @@
+import os
+import sys
+import pytest
+
+# Ensure package import without installation
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from macbot.conversation_manager import ConversationManager, ResponseState
+import threading
+
+
+def test_streaming_response_updates_history():
+    manager = ConversationManager()
+    manager.lock = threading.RLock()
+    manager.start_conversation()
+    manager.start_response()
+
+    manager.update_response('Hello', is_complete=False)
+    assert manager.current_context.ai_response == 'Hello'
+    assert manager.current_context.response_state == ResponseState.STREAMING
+
+    manager.update_response('Hello world', is_complete=True)
+    assert manager.current_context.ai_response == 'Hello world'
+    assert manager.current_context.response_state == ResponseState.COMPLETED
+
+    history = manager.get_recent_history()
+    assert history[-1]['content'] == 'Hello world'