diff --git a/test/test_websocket_manager.py b/test/test_websocket_manager.py
new file mode 100644
index 00000000..1befe3cf
--- /dev/null
+++ b/test/test_websocket_manager.py
@@ -0,0 +1,85 @@
+import pytest
+import asyncio
+import json
+from unittest.mock import AsyncMock, MagicMock, patch
+from fastapi import WebSocket
+from app.websockets.manager import ConnectionManager, handle_websocket_session
+
+
+@pytest.fixture
+def mock_websocket():
+    ws = AsyncMock(spec=WebSocket)
+    ws.accept = AsyncMock()
+    ws.send_text = AsyncMock()
+    ws.send_json = AsyncMock()
+    ws.receive_text = AsyncMock()
+    return ws
+
+
+@pytest.fixture
+def manager():
+    mgr = ConnectionManager(redis_url="redis://localhost:6379")
+    mgr.pubsub = MagicMock()
+    mgr.pubsub.subscribe = AsyncMock()
+    mgr.pubsub.unsubscribe = AsyncMock()
+    return mgr
+
+
+@pytest.mark.asyncio
+async def test_connect_and_disconnect(manager, mock_websocket):
+    await manager.connect(mock_websocket)
+    assert mock_websocket in manager.client_channels
+    assert len(manager.client_channels[mock_websocket]) == 0
+
+    manager.disconnect(mock_websocket)
+    assert mock_websocket not in manager.client_channels
+
+
+@pytest.mark.asyncio
+async def test_subscribe_and_unsubscribe(manager, mock_websocket):
+    await manager.connect(mock_websocket)
+    channel = "subscribe:pool:XLM-USDC"
+
+    # Subscribe
+    manager.subscribe(mock_websocket, channel)
+    assert channel in manager.subscriptions
+    assert mock_websocket in manager.subscriptions[channel]
+    assert channel in manager.client_channels[mock_websocket]
+
+    # Unsubscribe
+    manager.unsubscribe(mock_websocket, channel)
+    assert channel not in manager.subscriptions
+    assert channel not in manager.client_channels[mock_websocket]
+
+
+@pytest.mark.asyncio
+async def test_broadcast_to_channel(manager, mock_websocket):
+    await manager.connect(mock_websocket)
+    channel = "subscribe:pool:XLM-USDC"
+    manager.subscribe(mock_websocket, channel)
+
+    payload = {"price": 0.125, "volume": 15000}
+    await manager.broadcast_to_channel(channel, payload)
+
+    mock_websocket.send_text.assert_called_once_with(
+        json.dumps({"channel": channel, "data": payload})
+    )
+
+
+@pytest.mark.asyncio
+async def test_heartbeat_disconnects_stale_client(mock_websocket):
+    # Mock WebSocket that fails on send_json during heartbeat ping
+    mock_websocket.send_json.side_effect = Exception("Connection lost")
+    mock_websocket.receive_text.side_effect = asyncio.CancelledError()
+
+    with patch("app.websockets.manager.HEARTBEAT_INTERVAL", 0.01):
+        with patch("app.websockets.manager.manager.connect", new_callable=AsyncMock) as mock_conn, \
+             patch("app.websockets.manager.manager.disconnect") as mock_disc:
+            
+            try:
+                await handle_websocket_session(mock_websocket)
+            except asyncio.CancelledError:
+                pass
+
+            # Verify stale connection disconnect call was triggered
+            mock_disc.assert_called_with(mock_websocket)
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