diff --git a/VPLink.Tests/BotConfigurationTests.cs b/VPLink.Tests/BotConfigurationTests.cs
new file mode 100644
index 0000000..5239270
--- /dev/null
+++ b/VPLink.Tests/BotConfigurationTests.cs
@@ -0,0 +1,35 @@
+using NSubstitute;
+using NSubstitute.Extensions;
+using VPLink.Common.Configuration;
+using VPLink.Common.Services;
+
+namespace VPLink.Tests;
+
+public class BotConfigurationTests
+{
+    private IConfigurationService _configurationService = null!;
+
+    [SetUp]
+    public void Setup()
+    {
+        var configuration = Substitute.For<IBotConfiguration>();
+        configuration.AnnounceAvatarEvents.Returns(true);
+        configuration.AnnounceBots.Returns(false);
+        configuration.RelayBotMessages.Returns(false);
+
+        _configurationService = Substitute.For<IConfigurationService>();
+        _configurationService.Configure().BotConfiguration.Returns(configuration);
+    }
+
+    [Test]
+    public void BotConfiguration_ShouldReturnCorrectValues_GivenDefaultConfig()
+    {
+        IBotConfiguration configuration = _configurationService.BotConfiguration;
+        Assert.Multiple(() =>
+        {
+            Assert.That(configuration.AnnounceAvatarEvents, Is.True);
+            Assert.That(configuration.AnnounceBots, Is.False);
+            Assert.That(configuration.RelayBotMessages, Is.False);
+        });
+    }
+}
diff --git a/VPLink.Tests/DiscordConfigurationTests.cs b/VPLink.Tests/DiscordConfigurationTests.cs
new file mode 100644
index 0000000..50bfefe
--- /dev/null
+++ b/VPLink.Tests/DiscordConfigurationTests.cs
@@ -0,0 +1,33 @@
+using NSubstitute;
+using NSubstitute.Extensions;
+using VPLink.Common.Configuration;
+using VPLink.Common.Services;
+
+namespace VPLink.Tests;
+
+public class DiscordConfigurationTests
+{
+    private IConfigurationService _configurationService = null!;
+
+    [SetUp]
+    public void Setup()
+    {
+        var configuration = Substitute.For<IDiscordConfiguration>();
+        configuration.Token.Returns("DISCORD_TOKEN");
+        configuration.ChannelId.Returns(1234567890UL);
+
+        _configurationService = Substitute.For<IConfigurationService>();
+        _configurationService.Configure().DiscordConfiguration.Returns(configuration);
+    }
+
+    [Test]
+    public void DiscordConfiguration_ShouldReturnCorrectValues_GivenDefaultConfig()
+    {
+        IDiscordConfiguration configuration = _configurationService.DiscordConfiguration;
+        Assert.Multiple(() =>
+        {
+            Assert.That(configuration.Token, Is.EqualTo("DISCORD_TOKEN"));
+            Assert.That(configuration.ChannelId, Is.EqualTo(1234567890UL));
+        });
+    }
+}
diff --git a/VPLink.Tests/RelayTests.cs b/VPLink.Tests/RelayTests.cs
new file mode 100644
index 0000000..68a3ee1
--- /dev/null
+++ b/VPLink.Tests/RelayTests.cs
@@ -0,0 +1,64 @@
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
+using NSubstitute;
+using NSubstitute.Extensions;
+using VPLink.Common.Data;
+using VPLink.Common.Services;
+using VpSharp.Extensions;
+
+namespace VPLink.Tests;
+
+public class RelayTests
+{
+    private readonly Subject<RelayedMessage> _vpMessageReceived = new();
+    private readonly Subject<RelayedMessage> _discordMessageReceived = new();
+    private IVirtualParadiseMessageService _vpMessageService = null!;
+    private IDiscordMessageService _discordMessageService = null!;
+
+    [SetUp]
+    public void Setup()
+    {
+        _discordMessageService = Substitute.For<IDiscordMessageService>();
+        _discordMessageService.Configure().SendMessageAsync(Arg.Any<RelayedMessage>()).Returns(Task.CompletedTask);
+
+        _vpMessageService = Substitute.For<IVirtualParadiseMessageService>();
+        _vpMessageService.Configure().OnMessageReceived.Returns(_vpMessageReceived.AsObservable());
+        
+        _discordMessageService = Substitute.For<IDiscordMessageService>();
+        _discordMessageService.Configure().OnMessageReceived.Returns(_discordMessageReceived.AsObservable());
+        
+        _discordMessageReceived.SubscribeAsync(_vpMessageService.SendMessageAsync);
+        _vpMessageReceived.SubscribeAsync(_discordMessageService.SendMessageAsync);
+    }
+
+    [Test]
+    public void VirtualParadiseMessage_ShouldRelay_ToDiscordService()
+    {
+        var observer = Substitute.For<IObserver<RelayedMessage>>();
+        _vpMessageReceived.Subscribe(observer);
+
+        const string author = "Admin";
+        const string message = "Hello, world!";
+
+        _vpMessageReceived.OnNext(new RelayedMessage(author, message));
+
+        observer.Received(1).OnNext(Arg.Is<RelayedMessage>(m => m.Author == author && m.Content == message));
+        _discordMessageService.Received(1)
+            .SendMessageAsync(Arg.Is<RelayedMessage>(m => m.Author == author && m.Content == message));
+    }
+
+    [Test]
+    public void DiscordMessage_ShouldRelay_ToVirtualParadiseService()
+    {
+        var observer = Substitute.For<IObserver<RelayedMessage>>();
+        _discordMessageReceived.Subscribe(observer);
+
+        const string author = "Admin";
+        const string message = "Hello, world!";
+
+        _discordMessageReceived.OnNext(new RelayedMessage(author, message));
+
+        observer.Received(1).OnNext(Arg.Is<RelayedMessage>(m => m.Author == author && m.Content == message));
+        _vpMessageService.Received(1).SendMessageAsync(Arg.Is<RelayedMessage>(m => m.Author == author && m.Content == message));
+    }
+}
diff --git a/VPLink.Tests/UnitTest1.cs b/VPLink.Tests/UnitTest1.cs
deleted file mode 100644
index e27f1e1..0000000
--- a/VPLink.Tests/UnitTest1.cs
+++ /dev/null
@@ -1,15 +0,0 @@
-namespace VPLink.Tests;
-
-public class Tests
-{
-    [SetUp]
-    public void Setup()
-    {
-    }
-
-    [Test]
-    public void Test1()
-    {
-        Assert.Pass();
-    }
-}
diff --git a/VPLink.Tests/VPLink.Tests.csproj b/VPLink.Tests/VPLink.Tests.csproj
index 226d57f..fd7977f 100644
--- a/VPLink.Tests/VPLink.Tests.csproj
+++ b/VPLink.Tests/VPLink.Tests.csproj
@@ -11,10 +11,15 @@
 
     <ItemGroup>
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0"/>
+        <PackageReference Include="NSubstitute" Version="5.0.0"/>
         <PackageReference Include="NUnit" Version="3.13.3"/>
         <PackageReference Include="NUnit3TestAdapter" Version="4.4.2"/>
         <PackageReference Include="NUnit.Analyzers" Version="3.6.1"/>
         <PackageReference Include="coverlet.collector" Version="3.2.0"/>
     </ItemGroup>
 
+    <ItemGroup>
+        <ProjectReference Include="..\VPLink.Common\VPLink.Common.csproj"/>
+    </ItemGroup>
+
 </Project>
diff --git a/VPLink.Tests/VirtualParadiseConfigurationTests.cs b/VPLink.Tests/VirtualParadiseConfigurationTests.cs
new file mode 100644
index 0000000..c24f280
--- /dev/null
+++ b/VPLink.Tests/VirtualParadiseConfigurationTests.cs
@@ -0,0 +1,37 @@
+using NSubstitute;
+using NSubstitute.Extensions;
+using VPLink.Common.Configuration;
+using VPLink.Common.Services;
+
+namespace VPLink.Tests;
+
+public class VirtualParadiseConfigurationTests
+{
+    private IConfigurationService _configurationService = null!;
+
+    [SetUp]
+    public void Setup()
+    {
+        var configuration = Substitute.For<IVirtualParadiseConfiguration>();
+        configuration.Username.Returns("Admin");
+        configuration.Password.Returns("Password1234");
+        configuration.World.Returns("Blizzard");
+        configuration.BotName.Returns("VPLink");
+
+        _configurationService = Substitute.For<IConfigurationService>();
+        _configurationService.Configure().VirtualParadiseConfiguration.Returns(configuration);
+    }
+
+    [Test]
+    public void DiscordConfiguration_ShouldReturnCorrectValues_GivenDefaultConfig()
+    {
+        IVirtualParadiseConfiguration configuration = _configurationService.VirtualParadiseConfiguration;
+        Assert.Multiple(() =>
+        {
+            Assert.That(configuration.Username, Is.EqualTo("Admin"));
+            Assert.That(configuration.Password, Is.EqualTo("Password1234"));
+            Assert.That(configuration.World, Is.EqualTo("Blizzard"));
+            Assert.That(configuration.BotName, Is.EqualTo("VPLink"));
+        });
+    }
+}