diff --git a/packages/core-realtime/src/realtime-authenticator.interface.ts b/packages/core-realtime/src/realtime-authenticator.interface.ts
new file mode 100644
index 0000000..97a4ccb
--- /dev/null
+++ b/packages/core-realtime/src/realtime-authenticator.interface.ts
@@ -0,0 +1,6 @@
+export interface IRealtimeAuthenticator {
+  authenticate(handshake: {
+    cookies: Record<string, string>;
+    headers: Record<string, string>;
+  }): Promise<{ userId: string; roles: string[] } | null>;
+}