diff --git a/.gitea/workflows/run-tests.yml b/.gitea/workflows/run-tests.yml
new file mode 100644
index 0000000..d086f43
--- /dev/null
+++ b/.gitea/workflows/run-tests.yml
@@ -0,0 +1,37 @@
+name: Python Application Tests
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "*" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.13"]
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install Dependencies
+      run: |
+        python -m pip install --upgrade pip
+        # Install test dependencies
+        pip install pytest pytest-asyncio httpx
+        # Install application dependencies (assuming you have a requirements.txt)
+        # If you don't have one, create it with `pip freeze > requirements.txt`
+        # For now, we'll install the dependencies we know are needed from context
+        pip install fastapi "uvicorn[standard]" paho-mqtt requests
+
+    - name: Test with pytest
+      run: |
+        pytest
\ No newline at end of file
diff --git a/tests/test_op25_controller.py b/tests/test_op25_controller.py
new file mode 100644
index 0000000..5fb7b5c
--- /dev/null
+++ b/tests/test_op25_controller.py
@@ -0,0 +1,316 @@
+import pytest
+from fastapi.testclient import TestClient
+from unittest.mock import patch, MagicMock, mock_open, ANY
+import json
+import os
+import types
+from typing import List, Optional
+from pydantic import BaseModel
+
+# The router is included in the main app, so we test through it.
+# We need to adjust the python path for imports to work correctly
+import sys
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'app')))
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+
+# --- MOCK MODELS ---
+# The actual models.models file has a NameError (IcecastConfig used before definition).
+# Since we cannot edit the source code, we mock the module here to allow tests to run.
+mock_models = types.ModuleType("models.models")
+
+class MockTerminalConfig(BaseModel):
+    pass
+
+class MockTalkgroupTag(BaseModel):
+    tagDec: int
+    tagName: str
+
+class MockDecodeMode:
+    P25 = "P25"
+    ANALOG = "ANALOG"
+
+class MockIcecastConfig(BaseModel):
+    icecast_host: str
+    icecast_port: int
+    icecast_mountpoint: str
+    icecast_password: str
+
+class MockAnalogConfig(BaseModel):
+    systemName: str
+    frequency: str
+    nbfmSquelch: int
+
+class MockConfigGenerator(BaseModel):
+    type: str
+    systemName: str
+    channels: Optional[List[str]] = None
+    tags: Optional[List[MockTalkgroupTag]] = None
+    whitelist: Optional[str] = None
+    icecastConfig: Optional[MockIcecastConfig] = None
+    config: Optional[MockAnalogConfig] = None
+
+class MockChannelConfig(BaseModel):
+    name: Optional[str] = None
+    trunking_sysname: Optional[str] = None
+    enable_analog: Optional[str] = None
+    demod_type: Optional[str] = None
+    cqpsk_tracking: Optional[bool] = None
+    filter_type: Optional[str] = None
+    meta_stream_name: Optional[str] = None
+    channelName: Optional[str] = None
+    enableAnalog: Optional[str] = None
+    demodType: Optional[str] = None
+    frequency: Optional[str] = None
+    filterType: Optional[str] = None
+    nbfmSquelch: Optional[int] = None
+
+class MockDeviceConfig(BaseModel):
+    gain: Optional[str] = None
+
+class MockTrunkingChannelConfig(BaseModel):
+    sysname: str
+    control_channel_list: str
+    tagsFile: str
+    whitelist: str
+
+class MockTrunkingConfig(BaseModel):
+    module: str
+    chans: List[MockTrunkingChannelConfig]
+
+class MockMetadataStreamConfig(BaseModel):
+    stream_name: str
+    icecastServerAddress: str
+    icecastMountpoint: str
+    icecastPass: str
+
+class MockMetadataConfig(BaseModel):
+    streams: List[MockMetadataStreamConfig]
+
+
+mock_models.ConfigGenerator = MockConfigGenerator
+mock_models.DecodeMode = MockDecodeMode
+mock_models.ChannelConfig = MockChannelConfig
+mock_models.DeviceConfig = MockDeviceConfig
+mock_models.TrunkingConfig = MockTrunkingConfig
+mock_models.TrunkingChannelConfig = MockTrunkingChannelConfig
+mock_models.TerminalConfig = MockTerminalConfig
+mock_models.MetadataConfig = MockMetadataConfig
+mock_models.MetadataStreamConfig = MockMetadataStreamConfig
+mock_models.IcecastConfig = MockIcecastConfig
+mock_models.TalkgroupTag = MockTalkgroupTag
+
+sys.modules["models.models"] = mock_models
+sys.modules["models"] = types.ModuleType("models")
+sys.modules["models"].models = mock_models
+# -------------------
+
+from app.node_main import app
+
+# Use a client to make requests to the app
+client = TestClient(app)
+
+# Define a sample P25 config payload for testing
+SAMPLE_P25_CONFIG = {
+    "type": "P25",
+    "systemName": "TestSystem",
+    "channels": ["851.12345", "852.67890"],
+    "tags": [{"tagDec": 101, "tagName": "Group A"}, {"tagDec": 102, "tagName": "Group B"}],
+    "whitelist": "101",
+    "icecastConfig": {
+        "icecast_host": "localhost",
+        "icecast_port": 8000,
+        "icecast_mountpoint": "test",
+        "icecast_password": "hackme"
+    }
+}
+
+@pytest.fixture(autouse=True)
+def reset_and_mock_globals(monkeypatch):
+    """
+    Fixture to reset the global op25_process state and mock dependencies
+    before each test, ensuring test isolation.
+    """
+    # Reset the global process variable in the controller module
+    monkeypatch.setattr("routers.op25_controller.op25_process", None)
+
+    # Mock asyncio.sleep to prevent tests from actually waiting
+    mock_sleep = MagicMock()
+    monkeypatch.setattr("asyncio.sleep", mock_sleep)
+
+    # Mock os functions related to process groups
+    monkeypatch.setattr("os.killpg", MagicMock())
+    monkeypatch.setattr("os.getpgid", MagicMock(return_value=12345))
+
+
+@patch("routers.op25_controller.subprocess.Popen")
+def test_start_op25_success(mock_popen):
+    """Test the /start endpoint successfully starts the process."""
+    mock_process = MagicMock()
+    mock_process.pid = 12345
+    mock_popen.return_value = mock_process
+
+    response = client.post("/op25/start")
+    assert response.status_code == 200
+    assert response.json() == {"status": "OP25 started"}
+    mock_popen.assert_called_once()
+
+
+@patch("routers.op25_controller.subprocess.Popen", side_effect=Exception("Popen failed"))
+def test_start_op25_failure(mock_popen):
+    """Test the /start endpoint when Popen raises an exception."""
+    response = client.post("/op25/start")
+    assert response.status_code == 500
+    assert "Failed to start OP25" in response.json()["detail"]
+
+
+def test_stop_op25_not_running():
+    """Test the /stop endpoint when the process is not running."""
+    response = client.post("/op25/stop")
+    assert response.status_code == 200
+    assert response.json() == {"status": "OP25 was not running"}
+
+
+@patch("routers.op25_controller.subprocess.Popen")
+def test_stop_op25_success(mock_popen, monkeypatch):
+    """Test the /stop endpoint successfully stops a running process."""
+    mock_process = MagicMock()
+    mock_process.pid = 12345
+    mock_process.poll.return_value = None  # Indicates it's running
+    monkeypatch.setattr("routers.op25_controller.op25_process", mock_process)
+
+    response = client.post("/op25/stop")
+    assert response.status_code == 200
+    assert response.json() == {"status": "OP25 stopped"}
+    os.killpg.assert_called_with(os.getpgid(mock_process.pid), ANY)
+
+
+def test_get_status_not_running():
+    """Test the /status endpoint when the process is not running."""
+    response = client.get("/op25/status")
+    assert response.status_code == 200
+    data = response.json()
+    assert data["is_running"] is False
+    assert data["pid"] is None
+    assert data["active_system"] is None
+
+
+@patch("routers.op25_controller.get_current_system_from_config", return_value="TestSystem")
+@patch("routers.op25_controller.subprocess.Popen")
+def test_get_status_running(mock_popen, mock_get_system, monkeypatch):
+    """Test the /status endpoint when the process is running."""
+    mock_process = MagicMock()
+    mock_process.pid = 12345
+    mock_process.poll.return_value = None # Running
+    monkeypatch.setattr("routers.op25_controller.op25_process", mock_process)
+
+    response = client.get("/op25/status")
+    assert response.status_code == 200
+    data = response.json()
+    assert data["is_running"] is True
+    assert data["pid"] == 12345
+    assert data["active_system"] == "TestSystem"
+    mock_get_system.assert_called_once()
+
+
+@patch("builtins.open", new_callable=mock_open)
+@patch("routers.op25_controller.json.dump")
+@patch("routers.op25_controller.save_talkgroup_tags")
+@patch("routers.op25_controller.save_whitelist")
+@patch("routers.op25_controller.generate_liquid_script")
+@patch("routers.op25_controller.subprocess.Popen")
+def test_set_active_config_no_restart(mock_popen, mock_liquid, mock_white, mock_tags, mock_dump, mock_file):
+    """Test setting active config without restarting the radio."""
+    response = client.post("/op25/set_active_config?restart=false", json=SAMPLE_P25_CONFIG)
+
+    assert response.status_code == 200
+    assert response.json() == {"message": "Active configuration updated", "radio_restarted": False}
+
+    # Verify config files were written
+    mock_file.assert_called_with('/configs/active.cfg.json', 'w')
+    mock_dump.assert_called_once()
+    mock_tags.assert_called_with([MockTalkgroupTag(**t) for t in SAMPLE_P25_CONFIG["tags"]])
+    mock_white.assert_called_with(SAMPLE_P25_CONFIG["whitelist"])
+    mock_liquid.assert_called_with(MockIcecastConfig(**SAMPLE_P25_CONFIG["icecastConfig"]))
+
+    # Verify radio was NOT started/stopped
+    mock_popen.assert_not_called()
+    os.killpg.assert_not_called()
+
+
+@patch("routers.op25_controller.activate_config_from_library", return_value=True)
+@patch("routers.op25_controller.save_config_to_library")
+@patch("routers.op25_controller.save_library_sidecars")
+@patch("routers.op25_controller.subprocess.Popen")
+def test_set_active_config_with_save_to_library(mock_popen, mock_save_sidecars, mock_save_lib, mock_activate):
+    """Test setting active config and saving it to the library."""
+    library_name = "MyNewSystem"
+    response = client.post(
+        f"/op25/set_active_config?restart=true&save_to_library_name={library_name}",
+        json=SAMPLE_P25_CONFIG
+    )
+
+    assert response.status_code == 200
+    assert response.json()["radio_restarted"] is True
+
+    # Verify it was saved and then activated from the library
+    mock_save_lib.assert_called_with(library_name, ANY)
+    mock_save_sidecars.assert_called_with(library_name, ANY)
+    mock_activate.assert_called_with(library_name)
+
+    # Verify radio was restarted
+    assert mock_popen.call_count == 1
+
+
+@patch("routers.op25_controller.activate_config_from_library", return_value=True)
+@patch("routers.op25_controller.subprocess.Popen")
+def test_load_from_library_success(mock_popen, mock_activate):
+    """Test loading a configuration from the library."""
+    system_name = "ExistingSystem"
+    response = client.post(f"/op25/load_from_library?system_name={system_name}")
+
+    assert response.status_code == 200
+    assert response.json() == {"status": f"Loaded and started library config: {system_name}"}
+
+    # Verify activation and restart
+    mock_activate.assert_called_with(system_name)
+    assert mock_popen.call_count == 1
+
+
+@patch("routers.op25_controller.activate_config_from_library", return_value=False)
+def test_load_from_library_not_found(mock_activate):
+    """Test loading a non-existent configuration from the library."""
+    system_name = "NotFoundSystem"
+    response = client.post(f"/op25/load_from_library?system_name={system_name}")
+
+    assert response.status_code == 404
+    assert "not found in library" in response.json()["detail"]
+
+
+@patch("routers.op25_controller.save_config_to_library", return_value=True)
+@patch("routers.op25_controller.save_library_sidecars")
+def test_save_to_library(mock_save_sidecars, mock_save_lib):
+    """Test saving a configuration directly to the library."""
+    system_name = "NewLibSystem"
+    response = client.post(f"/op25/save_to_library?system_name={system_name}", json=SAMPLE_P25_CONFIG)
+
+    assert response.status_code == 200
+    assert response.json() == {"status": f"Config saved as {system_name}"}
+    mock_save_lib.assert_called_with(system_name, ANY)
+    mock_save_sidecars.assert_called_with(system_name, ANY)
+
+
+@patch("routers.op25_controller.scan_local_library", return_value=["System1.json", "System2.json"])
+def test_get_library(mock_scan):
+    """Test the /library endpoint."""
+    response = client.get("/op25/library")
+    assert response.status_code == 200
+    assert response.json() == ["System1.json", "System2.json"]
+    mock_scan.assert_called_once()
+
+
+@patch("routers.op25_controller.build_op25_config", side_effect=Exception("Build failed"))
+def test_set_active_config_build_failure(mock_build):
+    """Test error handling when config building fails."""
+    response = client.post("/op25/set_active_config", json=SAMPLE_P25_CONFIG)
+    assert response.status_code == 500
+    assert "Configuration error: Build failed" in response.json()["detail"]
\ No newline at end of file