diff --git a/Sources/src/main/kotlin/allin/data/FriendDataSource.kt b/Sources/src/main/kotlin/allin/data/FriendDataSource.kt
new file mode 100644
index 0000000..5a57e22
--- /dev/null
+++ b/Sources/src/main/kotlin/allin/data/FriendDataSource.kt
@@ -0,0 +1,9 @@
+package allin.data
+
+interface FriendDataSource {
+    fun addFriend(sender: String, receiver: String)
+    fun getFriendFromUserId(id: String)
+    fun getFriendFromUsername(username: String)
+    fun deleteFriend(senderId: String, receiverId: String)
+    fun isFriend(firstUser: String, secondUser: String)
+}
\ No newline at end of file
diff --git a/Sources/src/main/kotlin/allin/data/postgres/PostgresFriendDataSource.kt b/Sources/src/main/kotlin/allin/data/postgres/PostgresFriendDataSource.kt
new file mode 100644
index 0000000..050a3a9
--- /dev/null
+++ b/Sources/src/main/kotlin/allin/data/postgres/PostgresFriendDataSource.kt
@@ -0,0 +1,27 @@
+package allin.data.postgres
+
+import allin.data.FriendDataSource
+import org.ktorm.database.Database
+
+class PostgresFriendDataSource(private val database: Database) : FriendDataSource {
+    override fun addFriend(sender: String, receiver: String) {
+//        TODO("Not yet implemented")
+    }
+
+    override fun getFriendFromUserId(id: String) {
+        TODO("Not yet implemented")
+    }
+
+    override fun getFriendFromUsername(username: String) {
+        TODO("Not yet implemented")
+    }
+
+    override fun deleteFriend(senderId: String, receiverId: String) {
+        TODO("Not yet implemented")
+    }
+
+    override fun isFriend(firstUser: String, secondUser: String) {
+        TODO("Not yet implemented")
+    }
+
+}
\ No newline at end of file