diff --git a/src/oauth2server/DbInterface.php b/src/oauth2server/DbInterface.php
new file mode 100644
index 00000000..eeb8be42
--- /dev/null
+++ b/src/oauth2server/DbInterface.php
@@ -0,0 +1,30 @@
+<?php
+
+interface OAuth2ServerDatabase
+{
+    public function validateClient(string $clientId, $clientSecret, $redirectUri);
+
+    public function newSession(string $clientId, string $redirectUri, string $type = 'user', string $typeId, $authCode, $accessToken, string $stage = 'request');
+
+    public function updateSession(string $clientId, string $type = 'user', string $typeId, $authCode, $accessToken, string $stage);
+
+    public function deleteSession(string $clientId, string $typeId);
+
+    public function validateAuthCode(string $clientId, string $redirectUri, string $authCode);
+
+    public function getAccessToken(int $sessionId);
+
+    public function removeAuthCode(int $sessionId);
+
+    public function setAccessToken(int $sessionId, string $accessToken);
+
+    public function addSessionScope(int $sessionId, string $scope);
+
+    public function getScope(string $scope);
+
+    public function updateSessionScopeAccessToken(int $sesstionId, string $accessToken);
+
+    public function accessTokenScopes(string $accessToken);
+
+    public function validateUser(string $username, string $password);
+}
\ No newline at end of file
diff --git a/src/oauth2server/db.php b/src/oauth2server/db.php
deleted file mode 100644
index cceb7276..00000000
--- a/src/oauth2server/db.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-namespace LNCD\OAuth2server;
-
-interface OAuth2ServerDatabase
-{
-	
-}
\ No newline at end of file