diff --git a/backend/Program.cs b/backend/Program.cs
index 3c69ec4..cae286d 100644
--- a/backend/Program.cs
+++ b/backend/Program.cs
@@ -34,6 +34,7 @@ builder.Services.AddScoped<backend.Devices.DeviceTokenService>();
 builder.Services.AddScoped<backend.Pairing.PairingService>();
 builder.Services.AddSingleton<backend.Install.InstallScriptBuilder>();
 builder.Services.AddScoped<backend.Conversations.ConversationLog>();
+builder.Services.AddSingleton<backend.Realtime.OpenAIKeyProvider>();
 
 var app = builder.Build();
 
diff --git a/backend/Realtime/OpenAIKeyProvider.cs b/backend/Realtime/OpenAIKeyProvider.cs
new file mode 100644
index 0000000..51cc44e
--- /dev/null
+++ b/backend/Realtime/OpenAIKeyProvider.cs
@@ -0,0 +1,21 @@
+namespace backend.Realtime;
+
+public class OpenAIKeyProvider
+{
+    private readonly string? _key;
+
+    public OpenAIKeyProvider(IConfiguration cfg)
+    {
+        _key = cfg["OPENAI_API_KEY"] ?? cfg["OpenAI:ApiKey"];
+    }
+
+    public bool HasKey => !string.IsNullOrWhiteSpace(_key);
+
+    public string GetRequired()
+    {
+        if (string.IsNullOrWhiteSpace(_key))
+            throw new InvalidOperationException(
+                "OPENAI_API_KEY is not configured. Set the env var on the Coolify app.");
+        return _key!;
+    }
+}
diff --git a/backend/Realtime/RealtimeSettings.cs b/backend/Realtime/RealtimeSettings.cs
new file mode 100644
index 0000000..808a5eb
--- /dev/null
+++ b/backend/Realtime/RealtimeSettings.cs
@@ -0,0 +1,8 @@
+namespace backend.Realtime;
+
+public record RealtimeSettings(
+    string Model,
+    string Voice,
+    string SystemPrompt,
+    int IdleTimeoutSeconds,
+    IReadOnlySet<string> EnabledTools);