diff --git a/source/ast/ast.hon b/source/ast/ast.hon
index e1392b0..0ed083e 100644
--- a/source/ast/ast.hon
+++ b/source/ast/ast.hon
@@ -1 +1,50 @@
-# todo: move ast stuff from parser module to here
+import "@source/lexer"
+
+hide TokenId :: alias lexer.TokenId
+
+NodeId :: distinct u32
+ExtraId :: distinct u32
+
+NO_ID_NODE :: maxval!(NodeId)
+NO_ID_EXTRA :: maxval!(ExtraId)
+
+# unsafe access on its own; NodeKind serves as a the tag
+# that determines the variant.
+NodeData :: union {
+    token_id TokenId
+    node_id NodeId
+    extra_id ExtraId
+}
+
+Node :: struct {
+    kind NodeKind
+    main_token TokenId
+
+    data0 NodeData = NodeData{ node_id = NO_ID_NODE }
+    data1 NodeData = NodeData{ node_id = NO_ID_NODE }
+}
+
+NodeKind :: enum {
+    # LITERALS:
+    # * main_token: token literal
+    literal_int
+    literal_float
+    literal_string
+
+    # IDENTIFIER EXPR:
+    # * main_token: token literal
+    expr_identifier
+
+    expr_unary
+    expr_binary
+
+    # DECL:
+    # * main_token: symbol name (identifier)
+    # * data0: ExtraId
+    #   + extra[data0]: NodeId - type identifier node
+    #   + extra[data0 + 1]: NodeId - initializer expression
+    # * data1: TokenId of either `::` or `=` indicating mutability
+    stmt_decl
+
+    invalid
+}
diff --git a/source/parser/parser.hon b/source/parser/parser.hon
index 602c580..7ad7ae8 100644
--- a/source/parser/parser.hon
+++ b/source/parser/parser.hon
@@ -5,12 +5,7 @@ import "@std/debug"
 import "@std/enums/enummap"
 
 import "@source/lexer"
-
-NodeId :: distinct u32
-ExtraId :: distinct u32
-
-NO_ID_NODE :: maxval!(NodeId)
-NO_ID_EXTRA :: maxval!(ExtraId)
+import "@source/ast"
 
 # todo: move error stuff into a separate file
 
@@ -40,45 +35,13 @@ error_msg_map std.EnumMap(ErrorCode, ErrorDetails) :: enummap.init({
 hide Token :: alias lexer.Token
 hide TokenId :: alias lexer.TokenId
 hide TokenKind :: alias lexer.TokenKind
+hide Node :: alias ast.Node
+hide NodeId :: alias ast.NodeId
+hide ExtraId :: alias ast.ExtraId
+hide NodeData :: alias ast.NodeData
 
-NodeData :: union {
-    token_id TokenId
-    node_id NodeId
-    extra_id ExtraId
-}
-
-Node :: struct {
-    kind NodeKind
-    main_token TokenId
-
-    data0 NodeData = NodeData{ node_id = NO_ID_NODE }
-    data1 NodeData = NodeData{ node_id = NO_ID_NODE }
-}
-
-NodeKind :: enum {
-    # LITERALS:
-    # * main_token: token literal
-    literal_int
-    literal_float
-    literal_string
-
-    # IDENTIFIER EXPR:
-    # * main_token: token literal
-    expr_identifier
-
-    expr_unary
-    expr_binary
-
-    # DECL:
-    # * main_token: symbol name (identifier)
-    # * data0: ExtraId
-    #   + extra[data0]: NodeId - type identifier node
-    #   + extra[data0 + 1]: NodeId - initializer expression
-    # * data1: TokenId of either `::` or `=` indicating mutability
-    stmt_decl
-
-    invalid
-}
+hide NO_ID_NODE :: alias ast.NO_ID_NODE
+hide NO_ID_EXTRA :: alias ast.NO_ID_EXTRA
 
 State :: struct {
     nodes std.ArrayList(Node)