diff --git a/library/src/commonMain/kotlin/dev/usbharu/markdown/AstNode.kt b/library/src/commonMain/kotlin/dev/usbharu/markdown/AstNode.kt
new file mode 100644
index 0000000..068b181
--- /dev/null
+++ b/library/src/commonMain/kotlin/dev/usbharu/markdown/AstNode.kt
@@ -0,0 +1,19 @@
+package dev.usbharu.markdown
+
+import kotlin.collections.List
+
+sealed class AstNode
+data class RootNode(val node: AstNode) : AstNode()
+data class BodyNode(val body: List<AstNode>) : AstNode()
+sealed class BlockNode : AstNode()
+
+data class HeaderNode(val header: Int, val headerText: HeaderText?) : BlockNode()
+data class HeaderText(val text: String) : BlockNode()
+sealed interface QuotableNode
+data class QuoteNode(val nodes: List<QuotableNode>) : AstNode(), QuotableNode
+data object SeparatorNode : BlockNode()
+sealed class ListNode : BlockNode()
+data class DiscListNode(val node: InlineNode, val childList: List<ListNode>) : ListNode()
+data class DecimalListNode(val node: InlineNode, val childList: List<ListNode>) : ListNode()
+
+sealed class InlineNode : AstNode(), QuotableNode
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diff --git a/library/src/commonMain/kotlin/dev/usbharu/markdown/Parser.kt b/library/src/commonMain/kotlin/dev/usbharu/markdown/Parser.kt
new file mode 100644
index 0000000..be319c7
--- /dev/null
+++ b/library/src/commonMain/kotlin/dev/usbharu/markdown/Parser.kt
@@ -0,0 +1,9 @@
+package dev.usbharu.markdown
+
+import kotlin.collections.List
+
+class Parser {
+    fun parse(tokens: List<Token>) {
+
+    }
+}
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