diff --git a/src/main/kotlin/com/github/insanusmokrassar/postssystem/core/content/Content.kt b/src/main/kotlin/com/github/insanusmokrassar/postssystem/core/content/Content.kt
new file mode 100644
index 00000000..f4bd8786
--- /dev/null
+++ b/src/main/kotlin/com/github/insanusmokrassar/postssystem/core/content/Content.kt
@@ -0,0 +1,9 @@
+package com.github.insanusmokrassar.postssystem.core.content
+
+import org.joda.time.DateTime
+
+typealias ContentId = String
+
+interface Content {
+    val id: ContentId
+}
diff --git a/src/main/kotlin/com/github/insanusmokrassar/postssystem/core/content/TextContent.kt b/src/main/kotlin/com/github/insanusmokrassar/postssystem/core/content/TextContent.kt
new file mode 100644
index 00000000..f3bc7bff
--- /dev/null
+++ b/src/main/kotlin/com/github/insanusmokrassar/postssystem/core/content/TextContent.kt
@@ -0,0 +1,5 @@
+package com.github.insanusmokrassar.postssystem.core.content
+
+interface TextContent : Content {
+    val text: String
+}
\ No newline at end of file