diff --git a/docs/howto/analyze.md b/docs/howto/analyze.md
index e7c2c66b41..87541d093e 100644
--- a/docs/howto/analyze.md
+++ b/docs/howto/analyze.md
@@ -106,4 +106,6 @@ reports the result columns and parameters:
 ]
 ```
 
-Pass `--ast` to also include each statement's parsed AST under an `ast` key.
+Pass `--ast` to also include each statement's parsed AST under an `ast` key. It
+has the same shape as the output of [`parse`](parse.md), with every node tagged
+by type.
diff --git a/docs/howto/parse.md b/docs/howto/parse.md
index 2227c1f2b6..d46d35f394 100644
--- a/docs/howto/parse.md
+++ b/docs/howto/parse.md
@@ -48,15 +48,64 @@ The output is a JSON array with one object per statement:
     "name": "GetAuthor",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
+      "tag": "RawStmt",
+      "stmt": {
         "...": "..."
       },
-      "StmtLocation": 0,
-      "StmtLen": 42
+      "stmt_location": 0,
+      "stmt_len": 42
     }
   }
 ]
 ```
 
 Statements without a `-- name:` annotation (for example schema DDL) omit the
-`name` and `cmd` fields.
+`name` and `cmd` fields. Field names are `snake_case` versions of the AST node
+field names.
+
+## Node types
+
+Every node in the AST carries a `tag` naming its type. Some nodes have no
+fields of their own, so without it a star, a null literal and an untranslated
+clause would all print as `{}`.
+
+```json
+"val": {
+  "tag": "ColumnRef",
+  "name": "",
+  "fields": {
+    "tag": "List",
+    "items": [
+      {
+        "tag": "A_Star"
+      }
+    ]
+  },
+  "location": 93
+}
+```
+
+A `tag` of `TODO` marks a clause the dialect's converter does not translate
+yet. It means the clause was parsed but is not represented in the AST, not that
+the clause was absent from the query.
+
+## Absent fields
+
+A field the statement does not use is left out rather than printed as `null`.
+An `A_Const` carrying an integer reports only what it has:
+
+```json
+"val": {
+  "tag": "A_Const",
+  "val": {
+    "tag": "Integer",
+    "ival": 1
+  },
+  "location": 30
+}
+```
+
+Only absent fields — and empty lists, which engines construct differently for
+the same SQL — are omitted. A zero keeps its place, because zero is a value the
+parser can find: `stmt_location` is 0 for the first statement in a file, and
+`LIMIT 0` parses to an `ival` of 0.
diff --git a/internal/endtoend/testdata/analyze_ast/postgresql/stdout.txt b/internal/endtoend/testdata/analyze_ast/postgresql/stdout.txt
index b74264f687..1473a99cc5 100644
--- a/internal/endtoend/testdata/analyze_ast/postgresql/stdout.txt
+++ b/internal/endtoend/testdata/analyze_ast/postgresql/stdout.txt
@@ -24,99 +24,113 @@
       }
     ],
     "ast": {
-      "Stmt": {
-        "DistinctClause": {
-          "Items": null
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "distinct_clause": {
+          "tag": "List"
         },
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": {
-                "Items": null
+              "tag": "ResTarget",
+              "indirection": {
+                "tag": "List"
               },
-              "Val": {
-                "Name": "",
-                "Fields": {
-                  "Items": [
+              "val": {
+                "tag": "ColumnRef",
+                "name": "",
+                "fields": {
+                  "tag": "List",
+                  "items": [
                     {
-                      "Str": "name"
+                      "tag": "String",
+                      "str": "name"
                     }
                   ]
                 },
-                "Location": 35
+                "location": 35
               },
-              "Location": 35
+              "location": 35
             }
           ]
         },
-        "FromClause": {
-          "Items": [
+        "from_clause": {
+          "tag": "List",
+          "items": [
             {
-              "Catalogname": null,
-              "Schemaname": null,
-              "Relname": "authors",
-              "Inh": true,
-              "Relpersistence": 112,
-              "Alias": null,
-              "Location": 45
+              "tag": "RangeVar",
+              "relname": "authors",
+              "inh": true,
+              "relpersistence": 112,
+              "location": 45
             }
           ]
         },
-        "WhereClause": {
-          "Kind": 1,
-          "Name": {
-            "Items": [
+        "where_clause": {
+          "tag": "A_Expr",
+          "kind": 1,
+          "name": {
+            "tag": "List",
+            "items": [
               {
-                "Str": "="
+                "tag": "String",
+                "str": "="
               }
             ]
           },
-          "Lexpr": {
-            "Name": "",
-            "Fields": {
-              "Items": [
+          "lexpr": {
+            "tag": "ColumnRef",
+            "name": "",
+            "fields": {
+              "tag": "List",
+              "items": [
                 {
-                  "Str": "id"
+                  "tag": "String",
+                  "str": "id"
                 }
               ]
             },
-            "Location": 59
+            "location": 59
           },
-          "Rexpr": {
-            "Number": 1,
-            "Location": 64,
-            "Dollar": true
+          "rexpr": {
+            "tag": "ParamRef",
+            "number": 1,
+            "location": 64,
+            "dollar": true
           },
-          "Location": 62
+          "location": 62
         },
-        "GroupClause": {
-          "Items": null
+        "group_clause": {
+          "tag": "List"
         },
-        "HavingClause": {},
-        "WindowClause": {
-          "Items": null
+        "having_clause": {
+          "tag": "TODO"
         },
-        "ValuesLists": {
-          "Items": null
+        "window_clause": {
+          "tag": "List"
         },
-        "SortClause": {
-          "Items": null
+        "values_lists": {
+          "tag": "List"
         },
-        "LimitOffset": {},
-        "LimitCount": {},
-        "LockingClause": {
-          "Items": null
+        "sort_clause": {
+          "tag": "List"
         },
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "limit_offset": {
+          "tag": "TODO"
+        },
+        "limit_count": {
+          "tag": "TODO"
+        },
+        "locking_clause": {
+          "tag": "List"
+        },
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 66
+      "stmt_location": 0,
+      "stmt_len": 66
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/clickhouse/stdout.txt b/internal/endtoend/testdata/parse_basic/clickhouse/stdout.txt
index 28a5ce7e1f..82c35f9819 100644
--- a/internal/endtoend/testdata/parse_basic/clickhouse/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/clickhouse/stdout.txt
@@ -3,42 +3,31 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": null,
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": null,
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "tag": "ResTarget",
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 31
+                "location": 31
               },
-              "Location": 31
+              "location": 31
             }
           ]
         },
-        "FromClause": null,
-        "WhereClause": null,
-        "GroupClause": null,
-        "HavingClause": null,
-        "WindowClause": null,
-        "ValuesLists": null,
-        "SortClause": null,
-        "LimitOffset": null,
-        "LimitCount": null,
-        "LockingClause": null,
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 32
+      "stmt_location": 0,
+      "stmt_len": 32
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/duckdb/stdout.txt b/internal/endtoend/testdata/parse_basic/duckdb/stdout.txt
index ca847e616a..9c48f6b87e 100644
--- a/internal/endtoend/testdata/parse_basic/duckdb/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/duckdb/stdout.txt
@@ -3,42 +3,31 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": null,
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": null,
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "tag": "ResTarget",
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 30
+                "location": 30
               },
-              "Location": 30
+              "location": 30
             }
           ]
         },
-        "FromClause": null,
-        "WhereClause": null,
-        "GroupClause": null,
-        "HavingClause": null,
-        "WindowClause": null,
-        "ValuesLists": null,
-        "SortClause": null,
-        "LimitOffset": null,
-        "LimitCount": null,
-        "LockingClause": null,
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 33
+      "stmt_location": 0,
+      "stmt_len": 33
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/googlesql/stdout.txt b/internal/endtoend/testdata/parse_basic/googlesql/stdout.txt
index 086f885402..f1d543432e 100644
--- a/internal/endtoend/testdata/parse_basic/googlesql/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/googlesql/stdout.txt
@@ -3,42 +3,31 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": null,
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": null,
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "tag": "ResTarget",
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 30
+                "location": 30
               },
-              "Location": 30
+              "location": 30
             }
           ]
         },
-        "FromClause": null,
-        "WhereClause": null,
-        "GroupClause": null,
-        "HavingClause": null,
-        "WindowClause": null,
-        "ValuesLists": null,
-        "SortClause": null,
-        "LimitOffset": null,
-        "LimitCount": null,
-        "LockingClause": null,
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 31
+      "stmt_location": 0,
+      "stmt_len": 31
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/mssql/stdout.txt b/internal/endtoend/testdata/parse_basic/mssql/stdout.txt
index b20fbdcee5..a317604268 100644
--- a/internal/endtoend/testdata/parse_basic/mssql/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/mssql/stdout.txt
@@ -3,42 +3,31 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": null,
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": null,
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "tag": "ResTarget",
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 30
+                "location": 30
               },
-              "Location": 30
+              "location": 30
             }
           ]
         },
-        "FromClause": null,
-        "WhereClause": null,
-        "GroupClause": null,
-        "HavingClause": null,
-        "WindowClause": null,
-        "ValuesLists": null,
-        "SortClause": null,
-        "LimitOffset": null,
-        "LimitCount": null,
-        "LockingClause": null,
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 32
+      "stmt_location": 0,
+      "stmt_len": 32
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/mysql/stdout.txt b/internal/endtoend/testdata/parse_basic/mysql/stdout.txt
index e9ed28784f..baad161901 100644
--- a/internal/endtoend/testdata/parse_basic/mysql/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/mysql/stdout.txt
@@ -3,48 +3,40 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": null,
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": null,
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "tag": "ResTarget",
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 30
+                "location": 30
               },
-              "Location": 30
+              "location": 30
             }
           ]
         },
-        "FromClause": {
-          "Items": null
+        "from_clause": {
+          "tag": "List"
         },
-        "WhereClause": null,
-        "GroupClause": {
-          "Items": null
+        "group_clause": {
+          "tag": "List"
         },
-        "HavingClause": null,
-        "WindowClause": {
-          "Items": []
+        "window_clause": {
+          "tag": "List"
         },
-        "ValuesLists": null,
-        "SortClause": null,
-        "LimitOffset": null,
-        "LimitCount": null,
-        "LockingClause": null,
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 31
+      "stmt_location": 0,
+      "stmt_len": 31
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/postgresql/stdout.txt b/internal/endtoend/testdata/parse_basic/postgresql/stdout.txt
index fe35a664c7..da9c2f9040 100644
--- a/internal/endtoend/testdata/parse_basic/postgresql/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/postgresql/stdout.txt
@@ -3,58 +3,67 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": {
-          "Items": null
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "distinct_clause": {
+          "tag": "List"
         },
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": {
-                "Items": null
+              "tag": "ResTarget",
+              "indirection": {
+                "tag": "List"
               },
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 30
+                "location": 30
               },
-              "Location": 30
+              "location": 30
             }
           ]
         },
-        "FromClause": {
-          "Items": null
+        "from_clause": {
+          "tag": "List"
         },
-        "WhereClause": {},
-        "GroupClause": {
-          "Items": null
+        "where_clause": {
+          "tag": "TODO"
         },
-        "HavingClause": {},
-        "WindowClause": {
-          "Items": null
+        "group_clause": {
+          "tag": "List"
         },
-        "ValuesLists": {
-          "Items": null
+        "having_clause": {
+          "tag": "TODO"
         },
-        "SortClause": {
-          "Items": null
+        "window_clause": {
+          "tag": "List"
         },
-        "LimitOffset": {},
-        "LimitCount": {},
-        "LockingClause": {
-          "Items": null
+        "values_lists": {
+          "tag": "List"
         },
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "sort_clause": {
+          "tag": "List"
+        },
+        "limit_offset": {
+          "tag": "TODO"
+        },
+        "limit_count": {
+          "tag": "TODO"
+        },
+        "locking_clause": {
+          "tag": "List"
+        },
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 31
+      "stmt_location": 0,
+      "stmt_len": 31
     }
   }
 ]
diff --git a/internal/endtoend/testdata/parse_basic/sqlite/stdout.txt b/internal/endtoend/testdata/parse_basic/sqlite/stdout.txt
index c1303a9a1e..8cbf077101 100644
--- a/internal/endtoend/testdata/parse_basic/sqlite/stdout.txt
+++ b/internal/endtoend/testdata/parse_basic/sqlite/stdout.txt
@@ -3,50 +3,43 @@
     "name": "GetValue",
     "cmd": ":one",
     "ast": {
-      "Stmt": {
-        "DistinctClause": null,
-        "IntoClause": null,
-        "TargetList": {
-          "Items": [
+      "tag": "RawStmt",
+      "stmt": {
+        "tag": "SelectStmt",
+        "target_list": {
+          "tag": "List",
+          "items": [
             {
-              "Name": null,
-              "Indirection": null,
-              "Val": {
-                "Val": {
-                  "Ival": 1
+              "tag": "ResTarget",
+              "val": {
+                "tag": "A_Const",
+                "val": {
+                  "tag": "Integer",
+                  "ival": 1
                 },
-                "Location": 30
+                "location": 30
               },
-              "Location": 30
+              "location": 30
             }
           ]
         },
-        "FromClause": {
-          "Items": null
+        "from_clause": {
+          "tag": "List"
         },
-        "WhereClause": null,
-        "GroupClause": {
-          "Items": null
+        "group_clause": {
+          "tag": "List"
         },
-        "HavingClause": null,
-        "WindowClause": {
-          "Items": null
+        "window_clause": {
+          "tag": "List"
         },
-        "ValuesLists": {
-          "Items": null
+        "values_lists": {
+          "tag": "List"
         },
-        "SortClause": null,
-        "LimitOffset": null,
-        "LimitCount": null,
-        "LockingClause": null,
-        "WithClause": null,
-        "Op": 0,
-        "All": false,
-        "Larg": null,
-        "Rarg": null
+        "op": 0,
+        "all": false
       },
-      "StmtLocation": 0,
-      "StmtLen": 31
+      "stmt_location": 0,
+      "stmt_len": 31
     }
   }
 ]
diff --git a/internal/sql/ast/a_array_expr.go b/internal/sql/ast/a_array_expr.go
index 0437dac84f..ed11abf998 100644
--- a/internal/sql/ast/a_array_expr.go
+++ b/internal/sql/ast/a_array_expr.go
@@ -3,8 +3,10 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type A_ArrayExpr struct {
-	Elements *List
-	Location int
+	Tag NodeTag[A_ArrayExpr] `json:"tag"`
+
+	Elements *List `json:"elements,omitempty"`
+	Location int   `json:"location"`
 }
 
 func (n *A_ArrayExpr) Pos() int {
diff --git a/internal/sql/ast/a_const.go b/internal/sql/ast/a_const.go
index a6b610e349..0f507d99e3 100644
--- a/internal/sql/ast/a_const.go
+++ b/internal/sql/ast/a_const.go
@@ -3,8 +3,10 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type A_Const struct {
-	Val      Node
-	Location int
+	Tag NodeTag[A_Const] `json:"tag"`
+
+	Val      Node `json:"val,omitempty"`
+	Location int  `json:"location"`
 }
 
 func (n *A_Const) Pos() int {
diff --git a/internal/sql/ast/a_expr.go b/internal/sql/ast/a_expr.go
index ea3242337c..7501ff0eb6 100644
--- a/internal/sql/ast/a_expr.go
+++ b/internal/sql/ast/a_expr.go
@@ -7,7 +7,9 @@ import (
 )
 
 type A_Expr struct {
-	Kind A_Expr_Kind
+	Tag NodeTag[A_Expr] `json:"tag"`
+
+	Kind A_Expr_Kind `json:"kind"`
 	// Name is the operator, as a list of String nodes: PostgreSQL's
 	// operator space is open (user-defined and schema-qualified operators),
 	// so the shared tree keeps pg_query's shape rather than an enum. Each
@@ -15,10 +17,10 @@ type A_Expr struct {
 	// engine that accepts more than one spelling of the same operator
 	// (SQLite's != for <>, == for =), that is the author's spelling, which
 	// is how the printer preserves it.
-	Name     *List
-	Lexpr    Node
-	Rexpr    Node
-	Location int
+	Name     *List `json:"name,omitempty"`
+	Lexpr    Node  `json:"lexpr,omitempty"`
+	Rexpr    Node  `json:"rexpr,omitempty"`
+	Location int   `json:"location"`
 }
 
 func (n *A_Expr) Pos() int {
diff --git a/internal/sql/ast/a_indices.go b/internal/sql/ast/a_indices.go
index 7180f220e7..2f7715e8c7 100644
--- a/internal/sql/ast/a_indices.go
+++ b/internal/sql/ast/a_indices.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type A_Indices struct {
-	IsSlice bool
-	Lidx    Node
-	Uidx    Node
+	Tag NodeTag[A_Indices] `json:"tag"`
+
+	IsSlice bool `json:"is_slice"`
+	Lidx    Node `json:"lidx,omitempty"`
+	Uidx    Node `json:"uidx,omitempty"`
 }
 
 func (n *A_Indices) Pos() int {
diff --git a/internal/sql/ast/a_indirection.go b/internal/sql/ast/a_indirection.go
index b03b4621a9..df682bb285 100644
--- a/internal/sql/ast/a_indirection.go
+++ b/internal/sql/ast/a_indirection.go
@@ -1,8 +1,10 @@
 package ast
 
 type A_Indirection struct {
-	Arg         Node
-	Indirection *List
+	Tag NodeTag[A_Indirection] `json:"tag"`
+
+	Arg         Node  `json:"arg,omitempty"`
+	Indirection *List `json:"indirection,omitempty"`
 }
 
 func (n *A_Indirection) Pos() int {
diff --git a/internal/sql/ast/a_star.go b/internal/sql/ast/a_star.go
index 7e5f07b96a..c95d7c0b51 100644
--- a/internal/sql/ast/a_star.go
+++ b/internal/sql/ast/a_star.go
@@ -3,6 +3,7 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type A_Star struct {
+	Tag NodeTag[A_Star] `json:"tag"`
 }
 
 func (n *A_Star) Pos() int {
diff --git a/internal/sql/ast/access_priv.go b/internal/sql/ast/access_priv.go
index 8701adacdb..ab16946db3 100644
--- a/internal/sql/ast/access_priv.go
+++ b/internal/sql/ast/access_priv.go
@@ -1,8 +1,10 @@
 package ast
 
 type AccessPriv struct {
-	PrivName *string
-	Cols     *List
+	Tag NodeTag[AccessPriv] `json:"tag"`
+
+	PrivName *string `json:"priv_name,omitempty"`
+	Cols     *List   `json:"cols,omitempty"`
 }
 
 func (n *AccessPriv) Pos() int {
diff --git a/internal/sql/ast/aggref.go b/internal/sql/ast/aggref.go
index 6642f4d9e3..f9c8a0833a 100644
--- a/internal/sql/ast/aggref.go
+++ b/internal/sql/ast/aggref.go
@@ -1,23 +1,25 @@
 package ast
 
 type Aggref struct {
-	Xpr           Node
-	Aggfnoid      Oid
-	Aggtype       Oid
-	Aggcollid     Oid
-	Inputcollid   Oid
-	Aggargtypes   *List
-	Aggdirectargs *List
-	Args          *List
-	Aggorder      *List
-	Aggdistinct   *List
-	Aggfilter     Node
-	Aggstar       bool
-	Aggvariadic   bool
-	Aggkind       byte
-	Agglevelsup   Index
-	Aggsplit      AggSplit
-	Location      int
+	Tag NodeTag[Aggref] `json:"tag"`
+
+	Xpr           Node     `json:"xpr,omitempty"`
+	Aggfnoid      Oid      `json:"aggfnoid"`
+	Aggtype       Oid      `json:"aggtype"`
+	Aggcollid     Oid      `json:"aggcollid"`
+	Inputcollid   Oid      `json:"inputcollid"`
+	Aggargtypes   *List    `json:"aggargtypes,omitempty"`
+	Aggdirectargs *List    `json:"aggdirectargs,omitempty"`
+	Args          *List    `json:"args,omitempty"`
+	Aggorder      *List    `json:"aggorder,omitempty"`
+	Aggdistinct   *List    `json:"aggdistinct,omitempty"`
+	Aggfilter     Node     `json:"aggfilter,omitempty"`
+	Aggstar       bool     `json:"aggstar"`
+	Aggvariadic   bool     `json:"aggvariadic"`
+	Aggkind       byte     `json:"aggkind"`
+	Agglevelsup   Index    `json:"agglevelsup"`
+	Aggsplit      AggSplit `json:"aggsplit"`
+	Location      int      `json:"location"`
 }
 
 func (n *Aggref) Pos() int {
diff --git a/internal/sql/ast/alias.go b/internal/sql/ast/alias.go
index 7123982305..198120f5d0 100644
--- a/internal/sql/ast/alias.go
+++ b/internal/sql/ast/alias.go
@@ -3,8 +3,10 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type Alias struct {
-	Aliasname *string
-	Colnames  *List
+	Tag NodeTag[Alias] `json:"tag"`
+
+	Aliasname *string `json:"aliasname,omitempty"`
+	Colnames  *List   `json:"colnames,omitempty"`
 }
 
 func (n *Alias) Pos() int {
diff --git a/internal/sql/ast/alter_collation_stmt.go b/internal/sql/ast/alter_collation_stmt.go
index fa78ed7bf1..fedcf5a9d1 100644
--- a/internal/sql/ast/alter_collation_stmt.go
+++ b/internal/sql/ast/alter_collation_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type AlterCollationStmt struct {
-	Collname *List
+	Tag NodeTag[AlterCollationStmt] `json:"tag"`
+
+	Collname *List `json:"collname,omitempty"`
 }
 
 func (n *AlterCollationStmt) Pos() int {
diff --git a/internal/sql/ast/alter_database_set_stmt.go b/internal/sql/ast/alter_database_set_stmt.go
index ba9926bed1..14d485eb30 100644
--- a/internal/sql/ast/alter_database_set_stmt.go
+++ b/internal/sql/ast/alter_database_set_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterDatabaseSetStmt struct {
-	Dbname  *string
-	Setstmt *VariableSetStmt
+	Tag NodeTag[AlterDatabaseSetStmt] `json:"tag"`
+
+	Dbname  *string          `json:"dbname,omitempty"`
+	Setstmt *VariableSetStmt `json:"setstmt,omitempty"`
 }
 
 func (n *AlterDatabaseSetStmt) Pos() int {
diff --git a/internal/sql/ast/alter_database_stmt.go b/internal/sql/ast/alter_database_stmt.go
index 84d91f089c..9eb3dae54d 100644
--- a/internal/sql/ast/alter_database_stmt.go
+++ b/internal/sql/ast/alter_database_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterDatabaseStmt struct {
-	Dbname  *string
-	Options *List
+	Tag NodeTag[AlterDatabaseStmt] `json:"tag"`
+
+	Dbname  *string `json:"dbname,omitempty"`
+	Options *List   `json:"options,omitempty"`
 }
 
 func (n *AlterDatabaseStmt) Pos() int {
diff --git a/internal/sql/ast/alter_default_privileges_stmt.go b/internal/sql/ast/alter_default_privileges_stmt.go
index 64632a726d..f72a412eb1 100644
--- a/internal/sql/ast/alter_default_privileges_stmt.go
+++ b/internal/sql/ast/alter_default_privileges_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterDefaultPrivilegesStmt struct {
-	Options *List
-	Action  *GrantStmt
+	Tag NodeTag[AlterDefaultPrivilegesStmt] `json:"tag"`
+
+	Options *List      `json:"options,omitempty"`
+	Action  *GrantStmt `json:"action,omitempty"`
 }
 
 func (n *AlterDefaultPrivilegesStmt) Pos() int {
diff --git a/internal/sql/ast/alter_domain_stmt.go b/internal/sql/ast/alter_domain_stmt.go
index f9f419937f..669b7a5337 100644
--- a/internal/sql/ast/alter_domain_stmt.go
+++ b/internal/sql/ast/alter_domain_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type AlterDomainStmt struct {
-	Subtype   byte
-	TypeName  *List
-	Name      *string
-	Def       Node
-	Behavior  DropBehavior
-	MissingOk bool
+	Tag NodeTag[AlterDomainStmt] `json:"tag"`
+
+	Subtype   byte         `json:"subtype"`
+	TypeName  *List        `json:"type_name,omitempty"`
+	Name      *string      `json:"name,omitempty"`
+	Def       Node         `json:"def,omitempty"`
+	Behavior  DropBehavior `json:"behavior"`
+	MissingOk bool         `json:"missing_ok"`
 }
 
 func (n *AlterDomainStmt) Pos() int {
diff --git a/internal/sql/ast/alter_enum_stmt.go b/internal/sql/ast/alter_enum_stmt.go
index 1346b3c0d0..70a6a850bd 100644
--- a/internal/sql/ast/alter_enum_stmt.go
+++ b/internal/sql/ast/alter_enum_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type AlterEnumStmt struct {
-	TypeName           *List
-	OldVal             *string
-	NewVal             *string
-	NewValNeighbor     *string
-	NewValIsAfter      bool
-	SkipIfNewValExists bool
+	Tag NodeTag[AlterEnumStmt] `json:"tag"`
+
+	TypeName           *List   `json:"type_name,omitempty"`
+	OldVal             *string `json:"old_val,omitempty"`
+	NewVal             *string `json:"new_val,omitempty"`
+	NewValNeighbor     *string `json:"new_val_neighbor,omitempty"`
+	NewValIsAfter      bool    `json:"new_val_is_after"`
+	SkipIfNewValExists bool    `json:"skip_if_new_val_exists"`
 }
 
 func (n *AlterEnumStmt) Pos() int {
diff --git a/internal/sql/ast/alter_event_trig_stmt.go b/internal/sql/ast/alter_event_trig_stmt.go
index eeb5f75d42..14356fabe7 100644
--- a/internal/sql/ast/alter_event_trig_stmt.go
+++ b/internal/sql/ast/alter_event_trig_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterEventTrigStmt struct {
-	Trigname  *string
-	Tgenabled byte
+	Tag NodeTag[AlterEventTrigStmt] `json:"tag"`
+
+	Trigname  *string `json:"trigname,omitempty"`
+	Tgenabled byte    `json:"tgenabled"`
 }
 
 func (n *AlterEventTrigStmt) Pos() int {
diff --git a/internal/sql/ast/alter_extension_contents_stmt.go b/internal/sql/ast/alter_extension_contents_stmt.go
index 27ad1c31d6..3821812720 100644
--- a/internal/sql/ast/alter_extension_contents_stmt.go
+++ b/internal/sql/ast/alter_extension_contents_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type AlterExtensionContentsStmt struct {
-	Extname *string
-	Action  int
-	Objtype ObjectType
-	Object  Node
+	Tag NodeTag[AlterExtensionContentsStmt] `json:"tag"`
+
+	Extname *string    `json:"extname,omitempty"`
+	Action  int        `json:"action"`
+	Objtype ObjectType `json:"objtype"`
+	Object  Node       `json:"object,omitempty"`
 }
 
 func (n *AlterExtensionContentsStmt) Pos() int {
diff --git a/internal/sql/ast/alter_extension_stmt.go b/internal/sql/ast/alter_extension_stmt.go
index 049e712c94..c1daf85e91 100644
--- a/internal/sql/ast/alter_extension_stmt.go
+++ b/internal/sql/ast/alter_extension_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterExtensionStmt struct {
-	Extname *string
-	Options *List
+	Tag NodeTag[AlterExtensionStmt] `json:"tag"`
+
+	Extname *string `json:"extname,omitempty"`
+	Options *List   `json:"options,omitempty"`
 }
 
 func (n *AlterExtensionStmt) Pos() int {
diff --git a/internal/sql/ast/alter_fdw_stmt.go b/internal/sql/ast/alter_fdw_stmt.go
index 12c6457d71..6a74137bfb 100644
--- a/internal/sql/ast/alter_fdw_stmt.go
+++ b/internal/sql/ast/alter_fdw_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterFdwStmt struct {
-	Fdwname     *string
-	FuncOptions *List
-	Options     *List
+	Tag NodeTag[AlterFdwStmt] `json:"tag"`
+
+	Fdwname     *string `json:"fdwname,omitempty"`
+	FuncOptions *List   `json:"func_options,omitempty"`
+	Options     *List   `json:"options,omitempty"`
 }
 
 func (n *AlterFdwStmt) Pos() int {
diff --git a/internal/sql/ast/alter_foreign_server_stmt.go b/internal/sql/ast/alter_foreign_server_stmt.go
index 9f3e8dbe64..fcdbad116f 100644
--- a/internal/sql/ast/alter_foreign_server_stmt.go
+++ b/internal/sql/ast/alter_foreign_server_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type AlterForeignServerStmt struct {
-	Servername *string
-	Version    *string
-	Options    *List
-	HasVersion bool
+	Tag NodeTag[AlterForeignServerStmt] `json:"tag"`
+
+	Servername *string `json:"servername,omitempty"`
+	Version    *string `json:"version,omitempty"`
+	Options    *List   `json:"options,omitempty"`
+	HasVersion bool    `json:"has_version"`
 }
 
 func (n *AlterForeignServerStmt) Pos() int {
diff --git a/internal/sql/ast/alter_function_stmt.go b/internal/sql/ast/alter_function_stmt.go
index 1193ab7656..93d393111d 100644
--- a/internal/sql/ast/alter_function_stmt.go
+++ b/internal/sql/ast/alter_function_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterFunctionStmt struct {
-	Func    *ObjectWithArgs
-	Actions *List
+	Tag NodeTag[AlterFunctionStmt] `json:"tag"`
+
+	Func    *ObjectWithArgs `json:"func,omitempty"`
+	Actions *List           `json:"actions,omitempty"`
 }
 
 func (n *AlterFunctionStmt) Pos() int {
diff --git a/internal/sql/ast/alter_object_depends_stmt.go b/internal/sql/ast/alter_object_depends_stmt.go
index 83cc3c9641..f7b46aeeab 100644
--- a/internal/sql/ast/alter_object_depends_stmt.go
+++ b/internal/sql/ast/alter_object_depends_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type AlterObjectDependsStmt struct {
-	ObjectType ObjectType
-	Relation   *RangeVar
-	Object     Node
-	Extname    Node
+	Tag NodeTag[AlterObjectDependsStmt] `json:"tag"`
+
+	ObjectType ObjectType `json:"object_type"`
+	Relation   *RangeVar  `json:"relation,omitempty"`
+	Object     Node       `json:"object,omitempty"`
+	Extname    Node       `json:"extname,omitempty"`
 }
 
 func (n *AlterObjectDependsStmt) Pos() int {
diff --git a/internal/sql/ast/alter_object_schema_stmt.go b/internal/sql/ast/alter_object_schema_stmt.go
index 664e6f1495..3a5a5bd332 100644
--- a/internal/sql/ast/alter_object_schema_stmt.go
+++ b/internal/sql/ast/alter_object_schema_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type AlterObjectSchemaStmt struct {
-	ObjectType ObjectType
-	Relation   *RangeVar
-	Object     Node
-	Newschema  *string
-	MissingOk  bool
+	Tag NodeTag[AlterObjectSchemaStmt] `json:"tag"`
+
+	ObjectType ObjectType `json:"object_type"`
+	Relation   *RangeVar  `json:"relation,omitempty"`
+	Object     Node       `json:"object,omitempty"`
+	Newschema  *string    `json:"newschema,omitempty"`
+	MissingOk  bool       `json:"missing_ok"`
 }
 
 func (n *AlterObjectSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/alter_op_family_stmt.go b/internal/sql/ast/alter_op_family_stmt.go
index 60655d76b0..7d287d5a26 100644
--- a/internal/sql/ast/alter_op_family_stmt.go
+++ b/internal/sql/ast/alter_op_family_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type AlterOpFamilyStmt struct {
-	Opfamilyname *List
-	Amname       *string
-	IsDrop       bool
-	Items        *List
+	Tag NodeTag[AlterOpFamilyStmt] `json:"tag"`
+
+	Opfamilyname *List   `json:"opfamilyname,omitempty"`
+	Amname       *string `json:"amname,omitempty"`
+	IsDrop       bool    `json:"is_drop"`
+	Items        *List   `json:"items,omitempty"`
 }
 
 func (n *AlterOpFamilyStmt) Pos() int {
diff --git a/internal/sql/ast/alter_operator_stmt.go b/internal/sql/ast/alter_operator_stmt.go
index 11ef659a8c..0d61c657a6 100644
--- a/internal/sql/ast/alter_operator_stmt.go
+++ b/internal/sql/ast/alter_operator_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterOperatorStmt struct {
-	Opername *ObjectWithArgs
-	Options  *List
+	Tag NodeTag[AlterOperatorStmt] `json:"tag"`
+
+	Opername *ObjectWithArgs `json:"opername,omitempty"`
+	Options  *List           `json:"options,omitempty"`
 }
 
 func (n *AlterOperatorStmt) Pos() int {
diff --git a/internal/sql/ast/alter_owner_stmt.go b/internal/sql/ast/alter_owner_stmt.go
index 8a4be65183..041c0d4d67 100644
--- a/internal/sql/ast/alter_owner_stmt.go
+++ b/internal/sql/ast/alter_owner_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type AlterOwnerStmt struct {
-	ObjectType ObjectType
-	Relation   *RangeVar
-	Object     Node
-	Newowner   *RoleSpec
+	Tag NodeTag[AlterOwnerStmt] `json:"tag"`
+
+	ObjectType ObjectType `json:"object_type"`
+	Relation   *RangeVar  `json:"relation,omitempty"`
+	Object     Node       `json:"object,omitempty"`
+	Newowner   *RoleSpec  `json:"newowner,omitempty"`
 }
 
 func (n *AlterOwnerStmt) Pos() int {
diff --git a/internal/sql/ast/alter_policy_stmt.go b/internal/sql/ast/alter_policy_stmt.go
index 03e814328c..b7f9d7be4f 100644
--- a/internal/sql/ast/alter_policy_stmt.go
+++ b/internal/sql/ast/alter_policy_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type AlterPolicyStmt struct {
-	PolicyName *string
-	Table      *RangeVar
-	Roles      *List
-	Qual       Node
-	WithCheck  Node
+	Tag NodeTag[AlterPolicyStmt] `json:"tag"`
+
+	PolicyName *string   `json:"policy_name,omitempty"`
+	Table      *RangeVar `json:"table,omitempty"`
+	Roles      *List     `json:"roles,omitempty"`
+	Qual       Node      `json:"qual,omitempty"`
+	WithCheck  Node      `json:"with_check,omitempty"`
 }
 
 func (n *AlterPolicyStmt) Pos() int {
diff --git a/internal/sql/ast/alter_publication_stmt.go b/internal/sql/ast/alter_publication_stmt.go
index c1288858eb..718368fd26 100644
--- a/internal/sql/ast/alter_publication_stmt.go
+++ b/internal/sql/ast/alter_publication_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type AlterPublicationStmt struct {
-	Pubname      *string
-	Options      *List
-	Tables       *List
-	ForAllTables bool
-	TableAction  DefElemAction
+	Tag NodeTag[AlterPublicationStmt] `json:"tag"`
+
+	Pubname      *string       `json:"pubname,omitempty"`
+	Options      *List         `json:"options,omitempty"`
+	Tables       *List         `json:"tables,omitempty"`
+	ForAllTables bool          `json:"for_all_tables"`
+	TableAction  DefElemAction `json:"table_action"`
 }
 
 func (n *AlterPublicationStmt) Pos() int {
diff --git a/internal/sql/ast/alter_role_set_stmt.go b/internal/sql/ast/alter_role_set_stmt.go
index cda679017c..a973ccb4a4 100644
--- a/internal/sql/ast/alter_role_set_stmt.go
+++ b/internal/sql/ast/alter_role_set_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterRoleSetStmt struct {
-	Role     *RoleSpec
-	Database *string
-	Setstmt  *VariableSetStmt
+	Tag NodeTag[AlterRoleSetStmt] `json:"tag"`
+
+	Role     *RoleSpec        `json:"role,omitempty"`
+	Database *string          `json:"database,omitempty"`
+	Setstmt  *VariableSetStmt `json:"setstmt,omitempty"`
 }
 
 func (n *AlterRoleSetStmt) Pos() int {
diff --git a/internal/sql/ast/alter_role_stmt.go b/internal/sql/ast/alter_role_stmt.go
index e616f05917..3c7d60767c 100644
--- a/internal/sql/ast/alter_role_stmt.go
+++ b/internal/sql/ast/alter_role_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterRoleStmt struct {
-	Role    *RoleSpec
-	Options *List
-	Action  int
+	Tag NodeTag[AlterRoleStmt] `json:"tag"`
+
+	Role    *RoleSpec `json:"role,omitempty"`
+	Options *List     `json:"options,omitempty"`
+	Action  int       `json:"action"`
 }
 
 func (n *AlterRoleStmt) Pos() int {
diff --git a/internal/sql/ast/alter_seq_stmt.go b/internal/sql/ast/alter_seq_stmt.go
index ca4c86a413..53e46d47c4 100644
--- a/internal/sql/ast/alter_seq_stmt.go
+++ b/internal/sql/ast/alter_seq_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type AlterSeqStmt struct {
-	Sequence    *RangeVar
-	Options     *List
-	ForIdentity bool
-	MissingOk   bool
+	Tag NodeTag[AlterSeqStmt] `json:"tag"`
+
+	Sequence    *RangeVar `json:"sequence,omitempty"`
+	Options     *List     `json:"options,omitempty"`
+	ForIdentity bool      `json:"for_identity"`
+	MissingOk   bool      `json:"missing_ok"`
 }
 
 func (n *AlterSeqStmt) Pos() int {
diff --git a/internal/sql/ast/alter_subscription_stmt.go b/internal/sql/ast/alter_subscription_stmt.go
index 443fc7bfb8..3b54140fe7 100644
--- a/internal/sql/ast/alter_subscription_stmt.go
+++ b/internal/sql/ast/alter_subscription_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type AlterSubscriptionStmt struct {
-	Kind        AlterSubscriptionType
-	Subname     *string
-	Conninfo    *string
-	Publication *List
-	Options     *List
+	Tag NodeTag[AlterSubscriptionStmt] `json:"tag"`
+
+	Kind        AlterSubscriptionType `json:"kind"`
+	Subname     *string               `json:"subname,omitempty"`
+	Conninfo    *string               `json:"conninfo,omitempty"`
+	Publication *List                 `json:"publication,omitempty"`
+	Options     *List                 `json:"options,omitempty"`
 }
 
 func (n *AlterSubscriptionStmt) Pos() int {
diff --git a/internal/sql/ast/alter_system_stmt.go b/internal/sql/ast/alter_system_stmt.go
index c5657f9c1a..724ad8f3a7 100644
--- a/internal/sql/ast/alter_system_stmt.go
+++ b/internal/sql/ast/alter_system_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type AlterSystemStmt struct {
-	Setstmt *VariableSetStmt
+	Tag NodeTag[AlterSystemStmt] `json:"tag"`
+
+	Setstmt *VariableSetStmt `json:"setstmt,omitempty"`
 }
 
 func (n *AlterSystemStmt) Pos() int {
diff --git a/internal/sql/ast/alter_table_cmd.go b/internal/sql/ast/alter_table_cmd.go
index 90ffd891eb..b357605dd8 100644
--- a/internal/sql/ast/alter_table_cmd.go
+++ b/internal/sql/ast/alter_table_cmd.go
@@ -30,12 +30,14 @@ func (t AlterTableType) String() string {
 }
 
 type AlterTableCmd struct {
-	Subtype   AlterTableType
-	Name      *string
-	Def       *ColumnDef
-	Newowner  *RoleSpec
-	Behavior  DropBehavior
-	MissingOk bool
+	Tag NodeTag[AlterTableCmd] `json:"tag"`
+
+	Subtype   AlterTableType `json:"subtype"`
+	Name      *string        `json:"name,omitempty"`
+	Def       *ColumnDef     `json:"def,omitempty"`
+	Newowner  *RoleSpec      `json:"newowner,omitempty"`
+	Behavior  DropBehavior   `json:"behavior"`
+	MissingOk bool           `json:"missing_ok"`
 }
 
 func (n *AlterTableCmd) Pos() int {
diff --git a/internal/sql/ast/alter_table_move_all_stmt.go b/internal/sql/ast/alter_table_move_all_stmt.go
index 39f1256083..ac028a06aa 100644
--- a/internal/sql/ast/alter_table_move_all_stmt.go
+++ b/internal/sql/ast/alter_table_move_all_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type AlterTableMoveAllStmt struct {
-	OrigTablespacename *string
-	Objtype            ObjectType
-	Roles              *List
-	NewTablespacename  *string
-	Nowait             bool
+	Tag NodeTag[AlterTableMoveAllStmt] `json:"tag"`
+
+	OrigTablespacename *string    `json:"orig_tablespacename,omitempty"`
+	Objtype            ObjectType `json:"objtype"`
+	Roles              *List      `json:"roles,omitempty"`
+	NewTablespacename  *string    `json:"new_tablespacename,omitempty"`
+	Nowait             bool       `json:"nowait"`
 }
 
 func (n *AlterTableMoveAllStmt) Pos() int {
diff --git a/internal/sql/ast/alter_table_set_schema_stmt.go b/internal/sql/ast/alter_table_set_schema_stmt.go
index 890cb3e5e8..d7f62bf334 100644
--- a/internal/sql/ast/alter_table_set_schema_stmt.go
+++ b/internal/sql/ast/alter_table_set_schema_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterTableSetSchemaStmt struct {
-	Table     *TableName
-	NewSchema *string
-	MissingOk bool
+	Tag NodeTag[AlterTableSetSchemaStmt] `json:"tag"`
+
+	Table     *TableName `json:"table,omitempty"`
+	NewSchema *string    `json:"new_schema,omitempty"`
+	MissingOk bool       `json:"missing_ok"`
 }
 
 func (n *AlterTableSetSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/alter_table_space_options_stmt.go b/internal/sql/ast/alter_table_space_options_stmt.go
index fc49cfe6b8..f9b97b2d2f 100644
--- a/internal/sql/ast/alter_table_space_options_stmt.go
+++ b/internal/sql/ast/alter_table_space_options_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterTableSpaceOptionsStmt struct {
-	Tablespacename *string
-	Options        *List
-	IsReset        bool
+	Tag NodeTag[AlterTableSpaceOptionsStmt] `json:"tag"`
+
+	Tablespacename *string `json:"tablespacename,omitempty"`
+	Options        *List   `json:"options,omitempty"`
+	IsReset        bool    `json:"is_reset"`
 }
 
 func (n *AlterTableSpaceOptionsStmt) Pos() int {
diff --git a/internal/sql/ast/alter_table_stmt.go b/internal/sql/ast/alter_table_stmt.go
index afbf014b07..5e541023f1 100644
--- a/internal/sql/ast/alter_table_stmt.go
+++ b/internal/sql/ast/alter_table_stmt.go
@@ -3,16 +3,18 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type AlterTableStmt struct {
+	Tag NodeTag[AlterTableStmt] `json:"tag"`
+
 	// TODO: Only TableName or Relation should be defined
-	Relation  *RangeVar
-	Table     *TableName
-	Cmds      *List
-	MissingOk bool
-	Relkind   ObjectType
+	Relation  *RangeVar  `json:"relation,omitempty"`
+	Table     *TableName `json:"table,omitempty"`
+	Cmds      *List      `json:"cmds,omitempty"`
+	MissingOk bool       `json:"missing_ok"`
+	Relkind   ObjectType `json:"relkind"`
 	// Incomplete marks a statement whose source carried syntax this node
 	// does not model, such as column constraints beyond plain NOT NULL and
 	// PRIMARY KEY on an added column. No faithful rendering exists for it.
-	Incomplete bool
+	Incomplete bool `json:"incomplete"`
 }
 
 func (n *AlterTableStmt) Pos() int {
diff --git a/internal/sql/ast/alter_ts_configuration_stmt.go b/internal/sql/ast/alter_ts_configuration_stmt.go
index 6b58ada4e6..9ecd8bc2bb 100644
--- a/internal/sql/ast/alter_ts_configuration_stmt.go
+++ b/internal/sql/ast/alter_ts_configuration_stmt.go
@@ -1,13 +1,15 @@
 package ast
 
 type AlterTSConfigurationStmt struct {
-	Kind      AlterTSConfigType
-	Cfgname   *List
-	Tokentype *List
-	Dicts     *List
-	Override  bool
-	Replace   bool
-	MissingOk bool
+	Tag NodeTag[AlterTSConfigurationStmt] `json:"tag"`
+
+	Kind      AlterTSConfigType `json:"kind"`
+	Cfgname   *List             `json:"cfgname,omitempty"`
+	Tokentype *List             `json:"tokentype,omitempty"`
+	Dicts     *List             `json:"dicts,omitempty"`
+	Override  bool              `json:"override"`
+	Replace   bool              `json:"replace"`
+	MissingOk bool              `json:"missing_ok"`
 }
 
 func (n *AlterTSConfigurationStmt) Pos() int {
diff --git a/internal/sql/ast/alter_ts_dictionary_stmt.go b/internal/sql/ast/alter_ts_dictionary_stmt.go
index 0506c49b34..6c89127cca 100644
--- a/internal/sql/ast/alter_ts_dictionary_stmt.go
+++ b/internal/sql/ast/alter_ts_dictionary_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterTSDictionaryStmt struct {
-	Dictname *List
-	Options  *List
+	Tag NodeTag[AlterTSDictionaryStmt] `json:"tag"`
+
+	Dictname *List `json:"dictname,omitempty"`
+	Options  *List `json:"options,omitempty"`
 }
 
 func (n *AlterTSDictionaryStmt) Pos() int {
diff --git a/internal/sql/ast/alter_type_add_value_stmt.go b/internal/sql/ast/alter_type_add_value_stmt.go
index 56ae7dd9b7..a8878d6153 100644
--- a/internal/sql/ast/alter_type_add_value_stmt.go
+++ b/internal/sql/ast/alter_type_add_value_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type AlterTypeAddValueStmt struct {
-	Type               *TypeName
-	NewValue           *string
-	NewValHasNeighbor  bool
-	NewValNeighbor     *string
-	NewValIsAfter      bool
-	SkipIfNewValExists bool
+	Tag NodeTag[AlterTypeAddValueStmt] `json:"tag"`
+
+	Type               *TypeName `json:"type,omitempty"`
+	NewValue           *string   `json:"new_value,omitempty"`
+	NewValHasNeighbor  bool      `json:"new_val_has_neighbor"`
+	NewValNeighbor     *string   `json:"new_val_neighbor,omitempty"`
+	NewValIsAfter      bool      `json:"new_val_is_after"`
+	SkipIfNewValExists bool      `json:"skip_if_new_val_exists"`
 }
 
 func (n *AlterTypeAddValueStmt) Pos() int {
diff --git a/internal/sql/ast/alter_type_rename_value_stmt.go b/internal/sql/ast/alter_type_rename_value_stmt.go
index 376286511f..52e59d40d1 100644
--- a/internal/sql/ast/alter_type_rename_value_stmt.go
+++ b/internal/sql/ast/alter_type_rename_value_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterTypeRenameValueStmt struct {
-	Type     *TypeName
-	OldValue *string
-	NewValue *string
+	Tag NodeTag[AlterTypeRenameValueStmt] `json:"tag"`
+
+	Type     *TypeName `json:"type,omitempty"`
+	OldValue *string   `json:"old_value,omitempty"`
+	NewValue *string   `json:"new_value,omitempty"`
 }
 
 func (n *AlterTypeRenameValueStmt) Pos() int {
diff --git a/internal/sql/ast/alter_type_set_schema_stmt.go b/internal/sql/ast/alter_type_set_schema_stmt.go
index 22206d85cd..46d312beaa 100644
--- a/internal/sql/ast/alter_type_set_schema_stmt.go
+++ b/internal/sql/ast/alter_type_set_schema_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlterTypeSetSchemaStmt struct {
-	Type      *TypeName
-	NewSchema *string
+	Tag NodeTag[AlterTypeSetSchemaStmt] `json:"tag"`
+
+	Type      *TypeName `json:"type,omitempty"`
+	NewSchema *string   `json:"new_schema,omitempty"`
 }
 
 func (n *AlterTypeSetSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/alter_user_mapping_stmt.go b/internal/sql/ast/alter_user_mapping_stmt.go
index aeeb0912ae..ab85751f10 100644
--- a/internal/sql/ast/alter_user_mapping_stmt.go
+++ b/internal/sql/ast/alter_user_mapping_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type AlterUserMappingStmt struct {
-	User       *RoleSpec
-	Servername *string
-	Options    *List
+	Tag NodeTag[AlterUserMappingStmt] `json:"tag"`
+
+	User       *RoleSpec `json:"user,omitempty"`
+	Servername *string   `json:"servername,omitempty"`
+	Options    *List     `json:"options,omitempty"`
 }
 
 func (n *AlterUserMappingStmt) Pos() int {
diff --git a/internal/sql/ast/alternative_sub_plan.go b/internal/sql/ast/alternative_sub_plan.go
index 86031afd19..ad374d1d76 100644
--- a/internal/sql/ast/alternative_sub_plan.go
+++ b/internal/sql/ast/alternative_sub_plan.go
@@ -1,8 +1,10 @@
 package ast
 
 type AlternativeSubPlan struct {
-	Xpr      Node
-	Subplans *List
+	Tag NodeTag[AlternativeSubPlan] `json:"tag"`
+
+	Xpr      Node  `json:"xpr,omitempty"`
+	Subplans *List `json:"subplans,omitempty"`
 }
 
 func (n *AlternativeSubPlan) Pos() int {
diff --git a/internal/sql/ast/array_coerce_expr.go b/internal/sql/ast/array_coerce_expr.go
index 314c6881bf..ce8c95200f 100644
--- a/internal/sql/ast/array_coerce_expr.go
+++ b/internal/sql/ast/array_coerce_expr.go
@@ -1,15 +1,17 @@
 package ast
 
 type ArrayCoerceExpr struct {
-	Xpr          Node
-	Arg          Node
-	Elemfuncid   Oid
-	Resulttype   Oid
-	Resulttypmod int32
-	Resultcollid Oid
-	IsExplicit   bool
-	Coerceformat CoercionForm
-	Location     int
+	Tag NodeTag[ArrayCoerceExpr] `json:"tag"`
+
+	Xpr          Node         `json:"xpr,omitempty"`
+	Arg          Node         `json:"arg,omitempty"`
+	Elemfuncid   Oid          `json:"elemfuncid"`
+	Resulttype   Oid          `json:"resulttype"`
+	Resulttypmod int32        `json:"resulttypmod"`
+	Resultcollid Oid          `json:"resultcollid"`
+	IsExplicit   bool         `json:"is_explicit"`
+	Coerceformat CoercionForm `json:"coerceformat"`
+	Location     int          `json:"location"`
 }
 
 func (n *ArrayCoerceExpr) Pos() int {
diff --git a/internal/sql/ast/array_expr.go b/internal/sql/ast/array_expr.go
index c61aed8df7..753ed0f782 100644
--- a/internal/sql/ast/array_expr.go
+++ b/internal/sql/ast/array_expr.go
@@ -1,13 +1,15 @@
 package ast
 
 type ArrayExpr struct {
-	Xpr           Node
-	ArrayTypeid   Oid
-	ArrayCollid   Oid
-	ElementTypeid Oid
-	Elements      *List
-	Multidims     bool
-	Location      int
+	Tag NodeTag[ArrayExpr] `json:"tag"`
+
+	Xpr           Node  `json:"xpr,omitempty"`
+	ArrayTypeid   Oid   `json:"array_typeid"`
+	ArrayCollid   Oid   `json:"array_collid"`
+	ElementTypeid Oid   `json:"element_typeid"`
+	Elements      *List `json:"elements,omitempty"`
+	Multidims     bool  `json:"multidims"`
+	Location      int   `json:"location"`
 }
 
 func (n *ArrayExpr) Pos() int {
diff --git a/internal/sql/ast/array_ref.go b/internal/sql/ast/array_ref.go
index d94d800bb9..9fb4a35f5b 100644
--- a/internal/sql/ast/array_ref.go
+++ b/internal/sql/ast/array_ref.go
@@ -1,15 +1,17 @@
 package ast
 
 type ArrayRef struct {
-	Xpr             Node
-	Refarraytype    Oid
-	Refelemtype     Oid
-	Reftypmod       int32
-	Refcollid       Oid
-	Refupperindexpr *List
-	Reflowerindexpr *List
-	Refexpr         Node
-	Refassgnexpr    Node
+	Tag NodeTag[ArrayRef] `json:"tag"`
+
+	Xpr             Node  `json:"xpr,omitempty"`
+	Refarraytype    Oid   `json:"refarraytype"`
+	Refelemtype     Oid   `json:"refelemtype"`
+	Reftypmod       int32 `json:"reftypmod"`
+	Refcollid       Oid   `json:"refcollid"`
+	Refupperindexpr *List `json:"refupperindexpr,omitempty"`
+	Reflowerindexpr *List `json:"reflowerindexpr,omitempty"`
+	Refexpr         Node  `json:"refexpr,omitempty"`
+	Refassgnexpr    Node  `json:"refassgnexpr,omitempty"`
 }
 
 func (n *ArrayRef) Pos() int {
diff --git a/internal/sql/ast/between_expr.go b/internal/sql/ast/between_expr.go
index a160f1892c..f1e4508006 100644
--- a/internal/sql/ast/between_expr.go
+++ b/internal/sql/ast/between_expr.go
@@ -3,15 +3,17 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type BetweenExpr struct {
+	Tag NodeTag[BetweenExpr] `json:"tag"`
+
 	// Expr is the value expression to be compared.
-	Expr Node
+	Expr Node `json:"expr,omitempty"`
 	// Left is the left expression in the between statement.
-	Left Node
+	Left Node `json:"left,omitempty"`
 	// Right is the right expression in the between statement.
-	Right Node
+	Right Node `json:"right,omitempty"`
 	// Not is true, the expression is "not between".
-	Not      bool
-	Location int
+	Not      bool `json:"not"`
+	Location int  `json:"location"`
 }
 
 func (n *BetweenExpr) Pos() int {
diff --git a/internal/sql/ast/bit_string.go b/internal/sql/ast/bit_string.go
index f1f069d079..fb53f2d765 100644
--- a/internal/sql/ast/bit_string.go
+++ b/internal/sql/ast/bit_string.go
@@ -1,7 +1,9 @@
 package ast
 
 type BitString struct {
-	Str string
+	Tag NodeTag[BitString] `json:"tag"`
+
+	Str string `json:"str"`
 }
 
 func (n *BitString) Pos() int {
diff --git a/internal/sql/ast/block_id_data.go b/internal/sql/ast/block_id_data.go
index ce5563f6bb..bcb5171924 100644
--- a/internal/sql/ast/block_id_data.go
+++ b/internal/sql/ast/block_id_data.go
@@ -1,8 +1,10 @@
 package ast
 
 type BlockIdData struct {
-	BiHi uint16
-	BiLo uint16
+	Tag NodeTag[BlockIdData] `json:"tag"`
+
+	BiHi uint16 `json:"bi_hi"`
+	BiLo uint16 `json:"bi_lo"`
 }
 
 func (n *BlockIdData) Pos() int {
diff --git a/internal/sql/ast/bool_expr.go b/internal/sql/ast/bool_expr.go
index 65b4af53d2..9efea3de12 100644
--- a/internal/sql/ast/bool_expr.go
+++ b/internal/sql/ast/bool_expr.go
@@ -3,10 +3,12 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type BoolExpr struct {
-	Xpr      Node
-	Boolop   BoolExprType
-	Args     *List
-	Location int
+	Tag NodeTag[BoolExpr] `json:"tag"`
+
+	Xpr      Node         `json:"xpr,omitempty"`
+	Boolop   BoolExprType `json:"boolop"`
+	Args     *List        `json:"args,omitempty"`
+	Location int          `json:"location"`
 }
 
 func (n *BoolExpr) Pos() int {
diff --git a/internal/sql/ast/boolean.go b/internal/sql/ast/boolean.go
index 16a6db54da..b5a7502986 100644
--- a/internal/sql/ast/boolean.go
+++ b/internal/sql/ast/boolean.go
@@ -7,7 +7,9 @@ import (
 )
 
 type Boolean struct {
-	Boolval bool
+	Tag NodeTag[Boolean] `json:"tag"`
+
+	Boolval bool `json:"boolval"`
 }
 
 func (n *Boolean) Pos() int {
diff --git a/internal/sql/ast/boolean_test_expr.go b/internal/sql/ast/boolean_test_expr.go
index 7efbb46462..f6f3d90680 100644
--- a/internal/sql/ast/boolean_test_expr.go
+++ b/internal/sql/ast/boolean_test_expr.go
@@ -1,10 +1,12 @@
 package ast
 
 type BooleanTest struct {
-	Xpr          Node
-	Arg          Node
-	Booltesttype BoolTestType
-	Location     int
+	Tag NodeTag[BooleanTest] `json:"tag"`
+
+	Xpr          Node         `json:"xpr,omitempty"`
+	Arg          Node         `json:"arg,omitempty"`
+	Booltesttype BoolTestType `json:"booltesttype"`
+	Location     int          `json:"location"`
 }
 
 func (n *BooleanTest) Pos() int {
diff --git a/internal/sql/ast/call_stmt.go b/internal/sql/ast/call_stmt.go
index 6cba39986e..c64b5a8aa4 100644
--- a/internal/sql/ast/call_stmt.go
+++ b/internal/sql/ast/call_stmt.go
@@ -3,7 +3,9 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CallStmt struct {
-	FuncCall *FuncCall
+	Tag NodeTag[CallStmt] `json:"tag"`
+
+	FuncCall *FuncCall `json:"func_call,omitempty"`
 }
 
 func (n *CallStmt) Pos() int {
diff --git a/internal/sql/ast/case_expr.go b/internal/sql/ast/case_expr.go
index 52692b297b..4d9b6181a5 100644
--- a/internal/sql/ast/case_expr.go
+++ b/internal/sql/ast/case_expr.go
@@ -3,13 +3,15 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CaseExpr struct {
-	Xpr        Node
-	Casetype   Oid
-	Casecollid Oid
-	Arg        Node
-	Args       *List
-	Defresult  Node
-	Location   int
+	Tag NodeTag[CaseExpr] `json:"tag"`
+
+	Xpr        Node  `json:"xpr,omitempty"`
+	Casetype   Oid   `json:"casetype"`
+	Casecollid Oid   `json:"casecollid"`
+	Arg        Node  `json:"arg,omitempty"`
+	Args       *List `json:"args,omitempty"`
+	Defresult  Node  `json:"defresult,omitempty"`
+	Location   int   `json:"location"`
 }
 
 func (n *CaseExpr) Pos() int {
diff --git a/internal/sql/ast/case_test_expr.go b/internal/sql/ast/case_test_expr.go
index 8899985ca8..493293e93f 100644
--- a/internal/sql/ast/case_test_expr.go
+++ b/internal/sql/ast/case_test_expr.go
@@ -1,10 +1,12 @@
 package ast
 
 type CaseTestExpr struct {
-	Xpr       Node
-	TypeId    Oid
-	TypeMod   int32
-	Collation Oid
+	Tag NodeTag[CaseTestExpr] `json:"tag"`
+
+	Xpr       Node  `json:"xpr,omitempty"`
+	TypeId    Oid   `json:"type_id"`
+	TypeMod   int32 `json:"type_mod"`
+	Collation Oid   `json:"collation"`
 }
 
 func (n *CaseTestExpr) Pos() int {
diff --git a/internal/sql/ast/case_when.go b/internal/sql/ast/case_when.go
index 9636d24a97..fb39c4e269 100644
--- a/internal/sql/ast/case_when.go
+++ b/internal/sql/ast/case_when.go
@@ -3,10 +3,12 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CaseWhen struct {
-	Xpr      Node
-	Expr     Node
-	Result   Node
-	Location int
+	Tag NodeTag[CaseWhen] `json:"tag"`
+
+	Xpr      Node `json:"xpr,omitempty"`
+	Expr     Node `json:"expr,omitempty"`
+	Result   Node `json:"result,omitempty"`
+	Location int  `json:"location"`
 }
 
 func (n *CaseWhen) Pos() int {
diff --git a/internal/sql/ast/check_point_stmt.go b/internal/sql/ast/check_point_stmt.go
index b528fdc80b..55f6d13d67 100644
--- a/internal/sql/ast/check_point_stmt.go
+++ b/internal/sql/ast/check_point_stmt.go
@@ -1,6 +1,7 @@
 package ast
 
 type CheckPointStmt struct {
+	Tag NodeTag[CheckPointStmt] `json:"tag"`
 }
 
 func (n *CheckPointStmt) Pos() int {
diff --git a/internal/sql/ast/close_portal_stmt.go b/internal/sql/ast/close_portal_stmt.go
index 0b5afddeeb..d690543df9 100644
--- a/internal/sql/ast/close_portal_stmt.go
+++ b/internal/sql/ast/close_portal_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type ClosePortalStmt struct {
-	Portalname *string
+	Tag NodeTag[ClosePortalStmt] `json:"tag"`
+
+	Portalname *string `json:"portalname,omitempty"`
 }
 
 func (n *ClosePortalStmt) Pos() int {
diff --git a/internal/sql/ast/cluster_stmt.go b/internal/sql/ast/cluster_stmt.go
index 5e235eb482..f2b4588d51 100644
--- a/internal/sql/ast/cluster_stmt.go
+++ b/internal/sql/ast/cluster_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type ClusterStmt struct {
-	Relation  *RangeVar
-	Indexname *string
-	Verbose   bool
+	Tag NodeTag[ClusterStmt] `json:"tag"`
+
+	Relation  *RangeVar `json:"relation,omitempty"`
+	Indexname *string   `json:"indexname,omitempty"`
+	Verbose   bool      `json:"verbose"`
 }
 
 func (n *ClusterStmt) Pos() int {
diff --git a/internal/sql/ast/coalesce_expr.go b/internal/sql/ast/coalesce_expr.go
index 6aadffd30c..f51c2c5c8e 100644
--- a/internal/sql/ast/coalesce_expr.go
+++ b/internal/sql/ast/coalesce_expr.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CoalesceExpr struct {
-	Xpr            Node
-	Coalescetype   Oid
-	Coalescecollid Oid
-	Args           *List
-	Location       int
+	Tag NodeTag[CoalesceExpr] `json:"tag"`
+
+	Xpr            Node  `json:"xpr,omitempty"`
+	Coalescetype   Oid   `json:"coalescetype"`
+	Coalescecollid Oid   `json:"coalescecollid"`
+	Args           *List `json:"args,omitempty"`
+	Location       int   `json:"location"`
 }
 
 func (n *CoalesceExpr) Pos() int {
diff --git a/internal/sql/ast/coerce_to_domain.go b/internal/sql/ast/coerce_to_domain.go
index e81a83f15d..09e681b537 100644
--- a/internal/sql/ast/coerce_to_domain.go
+++ b/internal/sql/ast/coerce_to_domain.go
@@ -1,13 +1,15 @@
 package ast
 
 type CoerceToDomain struct {
-	Xpr            Node
-	Arg            Node
-	Resulttype     Oid
-	Resulttypmod   int32
-	Resultcollid   Oid
-	Coercionformat CoercionForm
-	Location       int
+	Tag NodeTag[CoerceToDomain] `json:"tag"`
+
+	Xpr            Node         `json:"xpr,omitempty"`
+	Arg            Node         `json:"arg,omitempty"`
+	Resulttype     Oid          `json:"resulttype"`
+	Resulttypmod   int32        `json:"resulttypmod"`
+	Resultcollid   Oid          `json:"resultcollid"`
+	Coercionformat CoercionForm `json:"coercionformat"`
+	Location       int          `json:"location"`
 }
 
 func (n *CoerceToDomain) Pos() int {
diff --git a/internal/sql/ast/coerce_to_domain_value.go b/internal/sql/ast/coerce_to_domain_value.go
index b2e26cb00c..d78b3bf89c 100644
--- a/internal/sql/ast/coerce_to_domain_value.go
+++ b/internal/sql/ast/coerce_to_domain_value.go
@@ -1,11 +1,13 @@
 package ast
 
 type CoerceToDomainValue struct {
-	Xpr       Node
-	TypeId    Oid
-	TypeMod   int32
-	Collation Oid
-	Location  int
+	Tag NodeTag[CoerceToDomainValue] `json:"tag"`
+
+	Xpr       Node  `json:"xpr,omitempty"`
+	TypeId    Oid   `json:"type_id"`
+	TypeMod   int32 `json:"type_mod"`
+	Collation Oid   `json:"collation"`
+	Location  int   `json:"location"`
 }
 
 func (n *CoerceToDomainValue) Pos() int {
diff --git a/internal/sql/ast/coerce_via_io.go b/internal/sql/ast/coerce_via_io.go
index 48aea6ce72..5c9f80970c 100644
--- a/internal/sql/ast/coerce_via_io.go
+++ b/internal/sql/ast/coerce_via_io.go
@@ -1,12 +1,14 @@
 package ast
 
 type CoerceViaIO struct {
-	Xpr          Node
-	Arg          Node
-	Resulttype   Oid
-	Resultcollid Oid
-	Coerceformat CoercionForm
-	Location     int
+	Tag NodeTag[CoerceViaIO] `json:"tag"`
+
+	Xpr          Node         `json:"xpr,omitempty"`
+	Arg          Node         `json:"arg,omitempty"`
+	Resulttype   Oid          `json:"resulttype"`
+	Resultcollid Oid          `json:"resultcollid"`
+	Coerceformat CoercionForm `json:"coerceformat"`
+	Location     int          `json:"location"`
 }
 
 func (n *CoerceViaIO) Pos() int {
diff --git a/internal/sql/ast/collate_clause.go b/internal/sql/ast/collate_clause.go
index 0c1629a05d..494b3e1f7b 100644
--- a/internal/sql/ast/collate_clause.go
+++ b/internal/sql/ast/collate_clause.go
@@ -1,9 +1,11 @@
 package ast
 
 type CollateClause struct {
-	Arg      Node
-	Collname *List
-	Location int
+	Tag NodeTag[CollateClause] `json:"tag"`
+
+	Arg      Node  `json:"arg,omitempty"`
+	Collname *List `json:"collname,omitempty"`
+	Location int   `json:"location"`
 }
 
 func (n *CollateClause) Pos() int {
diff --git a/internal/sql/ast/collate_expr.go b/internal/sql/ast/collate_expr.go
index 80483f75ce..c5643584b8 100644
--- a/internal/sql/ast/collate_expr.go
+++ b/internal/sql/ast/collate_expr.go
@@ -3,10 +3,12 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CollateExpr struct {
-	Xpr      Node
-	Arg      Node
-	CollOid  Oid
-	Location int
+	Tag NodeTag[CollateExpr] `json:"tag"`
+
+	Xpr      Node `json:"xpr,omitempty"`
+	Arg      Node `json:"arg,omitempty"`
+	CollOid  Oid  `json:"coll_oid"`
+	Location int  `json:"location"`
 }
 
 func (n *CollateExpr) Pos() int {
diff --git a/internal/sql/ast/column_def.go b/internal/sql/ast/column_def.go
index 6ac6a6e0c7..bc6687d4cb 100644
--- a/internal/sql/ast/column_def.go
+++ b/internal/sql/ast/column_def.go
@@ -3,40 +3,42 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type ColumnDef struct {
-	Colname string
+	Tag NodeTag[ColumnDef] `json:"tag"`
+
+	Colname string `json:"colname"`
 	// TypeName is the column's type for the catalog. When Typeless is set
 	// the author wrote no type at all — SQLite allows it — and the column
 	// prints without one, whatever TypeName carries.
-	TypeName   *TypeName
-	Typeless   bool
-	IsNotNull  bool
-	IsUnsigned bool
-	IsArray    bool
-	ArrayDims  int
-	Vals       *List
-	Length     *int
-	PrimaryKey bool
+	TypeName   *TypeName `json:"type_name,omitempty"`
+	Typeless   bool      `json:"typeless"`
+	IsNotNull  bool      `json:"is_not_null"`
+	IsUnsigned bool      `json:"is_unsigned"`
+	IsArray    bool      `json:"is_array"`
+	ArrayDims  int       `json:"array_dims"`
+	Vals       *List     `json:"vals,omitempty"`
+	Length     *int      `json:"length,omitempty"`
+	PrimaryKey bool      `json:"primary_key"`
 	// IsHidden marks a column a relation offers by name without listing it,
 	// like the column an sqlite fts5 table names after itself. The legacy
 	// catalog drops hidden columns; the core catalog keeps them out of star
 	// expansions and models.
-	IsHidden bool
+	IsHidden bool `json:"is_hidden"`
 
 	// From pg.ColumnDef
-	Inhcount      int
-	IsLocal       bool
-	IsFromType    bool
-	IsFromParent  bool
-	Storage       byte
-	RawDefault    Node
-	CookedDefault Node
-	Identity      byte
-	CollClause    *CollateClause
-	CollOid       Oid
-	Constraints   *List
-	Fdwoptions    *List
-	Location      int
-	Comment       string
+	Inhcount      int            `json:"inhcount"`
+	IsLocal       bool           `json:"is_local"`
+	IsFromType    bool           `json:"is_from_type"`
+	IsFromParent  bool           `json:"is_from_parent"`
+	Storage       byte           `json:"storage"`
+	RawDefault    Node           `json:"raw_default,omitempty"`
+	CookedDefault Node           `json:"cooked_default,omitempty"`
+	Identity      byte           `json:"identity"`
+	CollClause    *CollateClause `json:"coll_clause,omitempty"`
+	CollOid       Oid            `json:"coll_oid"`
+	Constraints   *List          `json:"constraints,omitempty"`
+	Fdwoptions    *List          `json:"fdwoptions,omitempty"`
+	Location      int            `json:"location"`
+	Comment       string         `json:"comment"`
 }
 
 func (n *ColumnDef) Pos() int {
diff --git a/internal/sql/ast/column_ref.go b/internal/sql/ast/column_ref.go
index 943311799d..f04c7b406d 100644
--- a/internal/sql/ast/column_ref.go
+++ b/internal/sql/ast/column_ref.go
@@ -7,11 +7,13 @@ import (
 )
 
 type ColumnRef struct {
-	Name string
+	Tag NodeTag[ColumnRef] `json:"tag"`
+
+	Name string `json:"name"`
 
 	// From pg.ColumnRef
-	Fields   *List
-	Location int
+	Fields   *List `json:"fields,omitempty"`
+	Location int   `json:"location"`
 }
 
 func (n *ColumnRef) Pos() int {
diff --git a/internal/sql/ast/comment_on_column_stmt.go b/internal/sql/ast/comment_on_column_stmt.go
index 6438b4ccc7..c35517ee27 100644
--- a/internal/sql/ast/comment_on_column_stmt.go
+++ b/internal/sql/ast/comment_on_column_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type CommentOnColumnStmt struct {
-	Table   *TableName
-	Col     *ColumnRef
-	Comment *string
+	Tag NodeTag[CommentOnColumnStmt] `json:"tag"`
+
+	Table   *TableName `json:"table,omitempty"`
+	Col     *ColumnRef `json:"col,omitempty"`
+	Comment *string    `json:"comment,omitempty"`
 }
 
 func (n *CommentOnColumnStmt) Pos() int {
diff --git a/internal/sql/ast/comment_on_schema_stmt.go b/internal/sql/ast/comment_on_schema_stmt.go
index edff162db0..aac64c4cac 100644
--- a/internal/sql/ast/comment_on_schema_stmt.go
+++ b/internal/sql/ast/comment_on_schema_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CommentOnSchemaStmt struct {
-	Schema  *String
-	Comment *string
+	Tag NodeTag[CommentOnSchemaStmt] `json:"tag"`
+
+	Schema  *String `json:"schema,omitempty"`
+	Comment *string `json:"comment,omitempty"`
 }
 
 func (n *CommentOnSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/comment_on_table_stmt.go b/internal/sql/ast/comment_on_table_stmt.go
index efb158f94b..d6056fa170 100644
--- a/internal/sql/ast/comment_on_table_stmt.go
+++ b/internal/sql/ast/comment_on_table_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CommentOnTableStmt struct {
-	Table   *TableName
-	Comment *string
+	Tag NodeTag[CommentOnTableStmt] `json:"tag"`
+
+	Table   *TableName `json:"table,omitempty"`
+	Comment *string    `json:"comment,omitempty"`
 }
 
 func (n *CommentOnTableStmt) Pos() int {
diff --git a/internal/sql/ast/comment_on_type_stmt.go b/internal/sql/ast/comment_on_type_stmt.go
index eb90bf5115..616fca31cc 100644
--- a/internal/sql/ast/comment_on_type_stmt.go
+++ b/internal/sql/ast/comment_on_type_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CommentOnTypeStmt struct {
-	Type    *TypeName
-	Comment *string
+	Tag NodeTag[CommentOnTypeStmt] `json:"tag"`
+
+	Type    *TypeName `json:"type,omitempty"`
+	Comment *string   `json:"comment,omitempty"`
 }
 
 func (n *CommentOnTypeStmt) Pos() int {
diff --git a/internal/sql/ast/comment_on_view_stmt.go b/internal/sql/ast/comment_on_view_stmt.go
index 2648d87918..c857f77c4c 100644
--- a/internal/sql/ast/comment_on_view_stmt.go
+++ b/internal/sql/ast/comment_on_view_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CommentOnViewStmt struct {
-	View    *TableName
-	Comment *string
+	Tag NodeTag[CommentOnViewStmt] `json:"tag"`
+
+	View    *TableName `json:"view,omitempty"`
+	Comment *string    `json:"comment,omitempty"`
 }
 
 func (n *CommentOnViewStmt) Pos() int {
diff --git a/internal/sql/ast/comment_stmt.go b/internal/sql/ast/comment_stmt.go
index 304827a294..61f6269ac1 100644
--- a/internal/sql/ast/comment_stmt.go
+++ b/internal/sql/ast/comment_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type CommentStmt struct {
-	Objtype ObjectType
-	Object  Node
-	Comment *string
+	Tag NodeTag[CommentStmt] `json:"tag"`
+
+	Objtype ObjectType `json:"objtype"`
+	Object  Node       `json:"object,omitempty"`
+	Comment *string    `json:"comment,omitempty"`
 }
 
 func (n *CommentStmt) Pos() int {
diff --git a/internal/sql/ast/common_table_expr.go b/internal/sql/ast/common_table_expr.go
index a9cc9d5022..84f7db47af 100644
--- a/internal/sql/ast/common_table_expr.go
+++ b/internal/sql/ast/common_table_expr.go
@@ -3,16 +3,18 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CommonTableExpr struct {
-	Ctename          *string
-	Aliascolnames    *List
-	Ctequery         Node
-	Location         int
-	Cterecursive     bool
-	Cterefcount      int
-	Ctecolnames      *List
-	Ctecoltypes      *List
-	Ctecoltypmods    *List
-	Ctecolcollations *List
+	Tag NodeTag[CommonTableExpr] `json:"tag"`
+
+	Ctename          *string `json:"ctename,omitempty"`
+	Aliascolnames    *List   `json:"aliascolnames,omitempty"`
+	Ctequery         Node    `json:"ctequery,omitempty"`
+	Location         int     `json:"location"`
+	Cterecursive     bool    `json:"cterecursive"`
+	Cterefcount      int     `json:"cterefcount"`
+	Ctecolnames      *List   `json:"ctecolnames,omitempty"`
+	Ctecoltypes      *List   `json:"ctecoltypes,omitempty"`
+	Ctecoltypmods    *List   `json:"ctecoltypmods,omitempty"`
+	Ctecolcollations *List   `json:"ctecolcollations,omitempty"`
 }
 
 func (n *CommonTableExpr) Pos() int {
diff --git a/internal/sql/ast/composite_type_stmt.go b/internal/sql/ast/composite_type_stmt.go
index f9a19b2653..eab6f7f4cc 100644
--- a/internal/sql/ast/composite_type_stmt.go
+++ b/internal/sql/ast/composite_type_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type CompositeTypeStmt struct {
-	TypeName *TypeName
+	Tag NodeTag[CompositeTypeStmt] `json:"tag"`
+
+	TypeName *TypeName `json:"type_name,omitempty"`
 }
 
 func (n *CompositeTypeStmt) Pos() int {
diff --git a/internal/sql/ast/const.go b/internal/sql/ast/const.go
index d33f0e84ed..58d33e9920 100644
--- a/internal/sql/ast/const.go
+++ b/internal/sql/ast/const.go
@@ -1,15 +1,17 @@
 package ast
 
 type Const struct {
-	Xpr         Node
-	Consttype   Oid
-	Consttypmod int32
-	Constcollid Oid
-	Constlen    int
-	Constvalue  Datum
-	Constisnull bool
-	Constbyval  bool
-	Location    int
+	Tag NodeTag[Const] `json:"tag"`
+
+	Xpr         Node  `json:"xpr,omitempty"`
+	Consttype   Oid   `json:"consttype"`
+	Consttypmod int32 `json:"consttypmod"`
+	Constcollid Oid   `json:"constcollid"`
+	Constlen    int   `json:"constlen"`
+	Constvalue  Datum `json:"constvalue"`
+	Constisnull bool  `json:"constisnull"`
+	Constbyval  bool  `json:"constbyval"`
+	Location    int   `json:"location"`
 }
 
 func (n *Const) Pos() int {
diff --git a/internal/sql/ast/constraint.go b/internal/sql/ast/constraint.go
index 5b628506af..bd9c7348f1 100644
--- a/internal/sql/ast/constraint.go
+++ b/internal/sql/ast/constraint.go
@@ -1,32 +1,34 @@
 package ast
 
 type Constraint struct {
-	Contype        ConstrType
-	Conname        *string
-	Deferrable     bool
-	Initdeferred   bool
-	Location       int
-	IsNoInherit    bool
-	RawExpr        Node
-	CookedExpr     *string
-	GeneratedWhen  byte
-	Keys           *List
-	Exclusions     *List
-	Options        *List
-	Indexname      *string
-	Indexspace     *string
-	AccessMethod   *string
-	WhereClause    Node
-	Pktable        *RangeVar
-	FkAttrs        *List
-	PkAttrs        *List
-	FkMatchtype    byte
-	FkUpdAction    byte
-	FkDelAction    byte
-	OldConpfeqop   *List
-	OldPktableOid  Oid
-	SkipValidation bool
-	InitiallyValid bool
+	Tag NodeTag[Constraint] `json:"tag"`
+
+	Contype        ConstrType `json:"contype"`
+	Conname        *string    `json:"conname,omitempty"`
+	Deferrable     bool       `json:"deferrable"`
+	Initdeferred   bool       `json:"initdeferred"`
+	Location       int        `json:"location"`
+	IsNoInherit    bool       `json:"is_no_inherit"`
+	RawExpr        Node       `json:"raw_expr,omitempty"`
+	CookedExpr     *string    `json:"cooked_expr,omitempty"`
+	GeneratedWhen  byte       `json:"generated_when"`
+	Keys           *List      `json:"keys,omitempty"`
+	Exclusions     *List      `json:"exclusions,omitempty"`
+	Options        *List      `json:"options,omitempty"`
+	Indexname      *string    `json:"indexname,omitempty"`
+	Indexspace     *string    `json:"indexspace,omitempty"`
+	AccessMethod   *string    `json:"access_method,omitempty"`
+	WhereClause    Node       `json:"where_clause,omitempty"`
+	Pktable        *RangeVar  `json:"pktable,omitempty"`
+	FkAttrs        *List      `json:"fk_attrs,omitempty"`
+	PkAttrs        *List      `json:"pk_attrs,omitempty"`
+	FkMatchtype    byte       `json:"fk_matchtype"`
+	FkUpdAction    byte       `json:"fk_upd_action"`
+	FkDelAction    byte       `json:"fk_del_action"`
+	OldConpfeqop   *List      `json:"old_conpfeqop,omitempty"`
+	OldPktableOid  Oid        `json:"old_pktable_oid"`
+	SkipValidation bool       `json:"skip_validation"`
+	InitiallyValid bool       `json:"initially_valid"`
 }
 
 func (n *Constraint) Pos() int {
diff --git a/internal/sql/ast/constraints_set_stmt.go b/internal/sql/ast/constraints_set_stmt.go
index ca0a33323d..b677dca751 100644
--- a/internal/sql/ast/constraints_set_stmt.go
+++ b/internal/sql/ast/constraints_set_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type ConstraintsSetStmt struct {
-	Constraints *List
-	Deferred    bool
+	Tag NodeTag[ConstraintsSetStmt] `json:"tag"`
+
+	Constraints *List `json:"constraints,omitempty"`
+	Deferred    bool  `json:"deferred"`
 }
 
 func (n *ConstraintsSetStmt) Pos() int {
diff --git a/internal/sql/ast/convert_rowtype_expr.go b/internal/sql/ast/convert_rowtype_expr.go
index 9e72c0c5c5..60c3f12c1d 100644
--- a/internal/sql/ast/convert_rowtype_expr.go
+++ b/internal/sql/ast/convert_rowtype_expr.go
@@ -1,11 +1,13 @@
 package ast
 
 type ConvertRowtypeExpr struct {
-	Xpr           Node
-	Arg           Node
-	Resulttype    Oid
-	Convertformat CoercionForm
-	Location      int
+	Tag NodeTag[ConvertRowtypeExpr] `json:"tag"`
+
+	Xpr           Node         `json:"xpr,omitempty"`
+	Arg           Node         `json:"arg,omitempty"`
+	Resulttype    Oid          `json:"resulttype"`
+	Convertformat CoercionForm `json:"convertformat"`
+	Location      int          `json:"location"`
 }
 
 func (n *ConvertRowtypeExpr) Pos() int {
diff --git a/internal/sql/ast/copy_stmt.go b/internal/sql/ast/copy_stmt.go
index 65d4dc69cc..93d83d6fde 100644
--- a/internal/sql/ast/copy_stmt.go
+++ b/internal/sql/ast/copy_stmt.go
@@ -1,13 +1,15 @@
 package ast
 
 type CopyStmt struct {
-	Relation  *RangeVar
-	Query     Node
-	Attlist   *List
-	IsFrom    bool
-	IsProgram bool
-	Filename  *string
-	Options   *List
+	Tag NodeTag[CopyStmt] `json:"tag"`
+
+	Relation  *RangeVar `json:"relation,omitempty"`
+	Query     Node      `json:"query,omitempty"`
+	Attlist   *List     `json:"attlist,omitempty"`
+	IsFrom    bool      `json:"is_from"`
+	IsProgram bool      `json:"is_program"`
+	Filename  *string   `json:"filename,omitempty"`
+	Options   *List     `json:"options,omitempty"`
 }
 
 func (n *CopyStmt) Pos() int {
diff --git a/internal/sql/ast/create_am_stmt.go b/internal/sql/ast/create_am_stmt.go
index 16fe6455c5..8f0859067b 100644
--- a/internal/sql/ast/create_am_stmt.go
+++ b/internal/sql/ast/create_am_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type CreateAmStmt struct {
-	Amname      *string
-	HandlerName *List
-	Amtype      byte
+	Tag NodeTag[CreateAmStmt] `json:"tag"`
+
+	Amname      *string `json:"amname,omitempty"`
+	HandlerName *List   `json:"handler_name,omitempty"`
+	Amtype      byte    `json:"amtype"`
 }
 
 func (n *CreateAmStmt) Pos() int {
diff --git a/internal/sql/ast/create_cast_stmt.go b/internal/sql/ast/create_cast_stmt.go
index 7ae94d3c6b..188d633c8c 100644
--- a/internal/sql/ast/create_cast_stmt.go
+++ b/internal/sql/ast/create_cast_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type CreateCastStmt struct {
-	Sourcetype *TypeName
-	Targettype *TypeName
-	Func       *ObjectWithArgs
-	Context    CoercionContext
-	Inout      bool
+	Tag NodeTag[CreateCastStmt] `json:"tag"`
+
+	Sourcetype *TypeName       `json:"sourcetype,omitempty"`
+	Targettype *TypeName       `json:"targettype,omitempty"`
+	Func       *ObjectWithArgs `json:"func,omitempty"`
+	Context    CoercionContext `json:"context"`
+	Inout      bool            `json:"inout"`
 }
 
 func (n *CreateCastStmt) Pos() int {
diff --git a/internal/sql/ast/create_conversion_stmt.go b/internal/sql/ast/create_conversion_stmt.go
index c0f4de14b1..38be006520 100644
--- a/internal/sql/ast/create_conversion_stmt.go
+++ b/internal/sql/ast/create_conversion_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type CreateConversionStmt struct {
-	ConversionName  *List
-	ForEncodingName *string
-	ToEncodingName  *string
-	FuncName        *List
-	Def             bool
+	Tag NodeTag[CreateConversionStmt] `json:"tag"`
+
+	ConversionName  *List   `json:"conversion_name,omitempty"`
+	ForEncodingName *string `json:"for_encoding_name,omitempty"`
+	ToEncodingName  *string `json:"to_encoding_name,omitempty"`
+	FuncName        *List   `json:"func_name,omitempty"`
+	Def             bool    `json:"def"`
 }
 
 func (n *CreateConversionStmt) Pos() int {
diff --git a/internal/sql/ast/create_domain_stmt.go b/internal/sql/ast/create_domain_stmt.go
index 3c541c4b2e..8cc2324c35 100644
--- a/internal/sql/ast/create_domain_stmt.go
+++ b/internal/sql/ast/create_domain_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreateDomainStmt struct {
-	Domainname  *List
-	TypeName    *TypeName
-	CollClause  *CollateClause
-	Constraints *List
+	Tag NodeTag[CreateDomainStmt] `json:"tag"`
+
+	Domainname  *List          `json:"domainname,omitempty"`
+	TypeName    *TypeName      `json:"type_name,omitempty"`
+	CollClause  *CollateClause `json:"coll_clause,omitempty"`
+	Constraints *List          `json:"constraints,omitempty"`
 }
 
 func (n *CreateDomainStmt) Pos() int {
diff --git a/internal/sql/ast/create_enum_stmt.go b/internal/sql/ast/create_enum_stmt.go
index a7d2df0fc9..f38316b4aa 100644
--- a/internal/sql/ast/create_enum_stmt.go
+++ b/internal/sql/ast/create_enum_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CreateEnumStmt struct {
-	TypeName *TypeName
-	Vals     *List
+	Tag NodeTag[CreateEnumStmt] `json:"tag"`
+
+	TypeName *TypeName `json:"type_name,omitempty"`
+	Vals     *List     `json:"vals,omitempty"`
 }
 
 func (n *CreateEnumStmt) Pos() int {
diff --git a/internal/sql/ast/create_event_trig_stmt.go b/internal/sql/ast/create_event_trig_stmt.go
index 276b32a6a0..eea8012286 100644
--- a/internal/sql/ast/create_event_trig_stmt.go
+++ b/internal/sql/ast/create_event_trig_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreateEventTrigStmt struct {
-	Trigname   *string
-	Eventname  *string
-	Whenclause *List
-	Funcname   *List
+	Tag NodeTag[CreateEventTrigStmt] `json:"tag"`
+
+	Trigname   *string `json:"trigname,omitempty"`
+	Eventname  *string `json:"eventname,omitempty"`
+	Whenclause *List   `json:"whenclause,omitempty"`
+	Funcname   *List   `json:"funcname,omitempty"`
 }
 
 func (n *CreateEventTrigStmt) Pos() int {
diff --git a/internal/sql/ast/create_extension_stmt.go b/internal/sql/ast/create_extension_stmt.go
index 140a10da4c..d73aed8308 100644
--- a/internal/sql/ast/create_extension_stmt.go
+++ b/internal/sql/ast/create_extension_stmt.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CreateExtensionStmt struct {
-	Extname     *string
-	IfNotExists bool
-	Options     *List
+	Tag NodeTag[CreateExtensionStmt] `json:"tag"`
+
+	Extname     *string `json:"extname,omitempty"`
+	IfNotExists bool    `json:"if_not_exists"`
+	Options     *List   `json:"options,omitempty"`
 }
 
 func (n *CreateExtensionStmt) Pos() int {
diff --git a/internal/sql/ast/create_fdw_stmt.go b/internal/sql/ast/create_fdw_stmt.go
index fd97378308..74cb794294 100644
--- a/internal/sql/ast/create_fdw_stmt.go
+++ b/internal/sql/ast/create_fdw_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type CreateFdwStmt struct {
-	Fdwname     *string
-	FuncOptions *List
-	Options     *List
+	Tag NodeTag[CreateFdwStmt] `json:"tag"`
+
+	Fdwname     *string `json:"fdwname,omitempty"`
+	FuncOptions *List   `json:"func_options,omitempty"`
+	Options     *List   `json:"options,omitempty"`
 }
 
 func (n *CreateFdwStmt) Pos() int {
diff --git a/internal/sql/ast/create_foreign_server_stmt.go b/internal/sql/ast/create_foreign_server_stmt.go
index b7d24445b4..da9d78a58e 100644
--- a/internal/sql/ast/create_foreign_server_stmt.go
+++ b/internal/sql/ast/create_foreign_server_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type CreateForeignServerStmt struct {
-	Servername  *string
-	Servertype  *string
-	Version     *string
-	Fdwname     *string
-	IfNotExists bool
-	Options     *List
+	Tag NodeTag[CreateForeignServerStmt] `json:"tag"`
+
+	Servername  *string `json:"servername,omitempty"`
+	Servertype  *string `json:"servertype,omitempty"`
+	Version     *string `json:"version,omitempty"`
+	Fdwname     *string `json:"fdwname,omitempty"`
+	IfNotExists bool    `json:"if_not_exists"`
+	Options     *List   `json:"options,omitempty"`
 }
 
 func (n *CreateForeignServerStmt) Pos() int {
diff --git a/internal/sql/ast/create_foreign_table_stmt.go b/internal/sql/ast/create_foreign_table_stmt.go
index 6661588786..764e72996d 100644
--- a/internal/sql/ast/create_foreign_table_stmt.go
+++ b/internal/sql/ast/create_foreign_table_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type CreateForeignTableStmt struct {
-	Base       *CreateStmt
-	Servername *string
-	Options    *List
+	Tag NodeTag[CreateForeignTableStmt] `json:"tag"`
+
+	Base       *CreateStmt `json:"base,omitempty"`
+	Servername *string     `json:"servername,omitempty"`
+	Options    *List       `json:"options,omitempty"`
 }
 
 func (n *CreateForeignTableStmt) Pos() int {
diff --git a/internal/sql/ast/create_function_stmt.go b/internal/sql/ast/create_function_stmt.go
index f5200085ee..3fb3bb79fa 100644
--- a/internal/sql/ast/create_function_stmt.go
+++ b/internal/sql/ast/create_function_stmt.go
@@ -3,13 +3,15 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CreateFunctionStmt struct {
-	Replace    bool
-	Params     *List
-	ReturnType *TypeName
-	Func       *FuncName
+	Tag NodeTag[CreateFunctionStmt] `json:"tag"`
+
+	Replace    bool      `json:"replace"`
+	Params     *List     `json:"params,omitempty"`
+	ReturnType *TypeName `json:"return_type,omitempty"`
+	Func       *FuncName `json:"func,omitempty"`
 	// TODO: Understand these two fields
-	Options    *List
-	WithClause *List
+	Options    *List `json:"options,omitempty"`
+	WithClause *List `json:"with_clause,omitempty"`
 }
 
 func (n *CreateFunctionStmt) Pos() int {
diff --git a/internal/sql/ast/create_op_class_item.go b/internal/sql/ast/create_op_class_item.go
index 09621bd0d8..0b1f4ad728 100644
--- a/internal/sql/ast/create_op_class_item.go
+++ b/internal/sql/ast/create_op_class_item.go
@@ -1,12 +1,14 @@
 package ast
 
 type CreateOpClassItem struct {
-	Itemtype    int
-	Name        *ObjectWithArgs
-	Number      int
-	OrderFamily *List
-	ClassArgs   *List
-	Storedtype  *TypeName
+	Tag NodeTag[CreateOpClassItem] `json:"tag"`
+
+	Itemtype    int             `json:"itemtype"`
+	Name        *ObjectWithArgs `json:"name,omitempty"`
+	Number      int             `json:"number"`
+	OrderFamily *List           `json:"order_family,omitempty"`
+	ClassArgs   *List           `json:"class_args,omitempty"`
+	Storedtype  *TypeName       `json:"storedtype,omitempty"`
 }
 
 func (n *CreateOpClassItem) Pos() int {
diff --git a/internal/sql/ast/create_op_class_stmt.go b/internal/sql/ast/create_op_class_stmt.go
index a4ab7b067c..9b606c4610 100644
--- a/internal/sql/ast/create_op_class_stmt.go
+++ b/internal/sql/ast/create_op_class_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type CreateOpClassStmt struct {
-	Opclassname  *List
-	Opfamilyname *List
-	Amname       *string
-	Datatype     *TypeName
-	Items        *List
-	IsDefault    bool
+	Tag NodeTag[CreateOpClassStmt] `json:"tag"`
+
+	Opclassname  *List     `json:"opclassname,omitempty"`
+	Opfamilyname *List     `json:"opfamilyname,omitempty"`
+	Amname       *string   `json:"amname,omitempty"`
+	Datatype     *TypeName `json:"datatype,omitempty"`
+	Items        *List     `json:"items,omitempty"`
+	IsDefault    bool      `json:"is_default"`
 }
 
 func (n *CreateOpClassStmt) Pos() int {
diff --git a/internal/sql/ast/create_op_family_stmt.go b/internal/sql/ast/create_op_family_stmt.go
index b939625ed3..4db1cc411b 100644
--- a/internal/sql/ast/create_op_family_stmt.go
+++ b/internal/sql/ast/create_op_family_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CreateOpFamilyStmt struct {
-	Opfamilyname *List
-	Amname       *string
+	Tag NodeTag[CreateOpFamilyStmt] `json:"tag"`
+
+	Opfamilyname *List   `json:"opfamilyname,omitempty"`
+	Amname       *string `json:"amname,omitempty"`
 }
 
 func (n *CreateOpFamilyStmt) Pos() int {
diff --git a/internal/sql/ast/create_p_lang_stmt.go b/internal/sql/ast/create_p_lang_stmt.go
index 5f11ce9eb1..f6d43980e9 100644
--- a/internal/sql/ast/create_p_lang_stmt.go
+++ b/internal/sql/ast/create_p_lang_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type CreatePLangStmt struct {
-	Replace     bool
-	Plname      *string
-	Plhandler   *List
-	Plinline    *List
-	Plvalidator *List
-	Pltrusted   bool
+	Tag NodeTag[CreatePLangStmt] `json:"tag"`
+
+	Replace     bool    `json:"replace"`
+	Plname      *string `json:"plname,omitempty"`
+	Plhandler   *List   `json:"plhandler,omitempty"`
+	Plinline    *List   `json:"plinline,omitempty"`
+	Plvalidator *List   `json:"plvalidator,omitempty"`
+	Pltrusted   bool    `json:"pltrusted"`
 }
 
 func (n *CreatePLangStmt) Pos() int {
diff --git a/internal/sql/ast/create_policy_stmt.go b/internal/sql/ast/create_policy_stmt.go
index 39e244f7a4..3d191a2480 100644
--- a/internal/sql/ast/create_policy_stmt.go
+++ b/internal/sql/ast/create_policy_stmt.go
@@ -1,13 +1,15 @@
 package ast
 
 type CreatePolicyStmt struct {
-	PolicyName *string
-	Table      *RangeVar
-	CmdName    *string
-	Permissive bool
-	Roles      *List
-	Qual       Node
-	WithCheck  Node
+	Tag NodeTag[CreatePolicyStmt] `json:"tag"`
+
+	PolicyName *string   `json:"policy_name,omitempty"`
+	Table      *RangeVar `json:"table,omitempty"`
+	CmdName    *string   `json:"cmd_name,omitempty"`
+	Permissive bool      `json:"permissive"`
+	Roles      *List     `json:"roles,omitempty"`
+	Qual       Node      `json:"qual,omitempty"`
+	WithCheck  Node      `json:"with_check,omitempty"`
 }
 
 func (n *CreatePolicyStmt) Pos() int {
diff --git a/internal/sql/ast/create_publication_stmt.go b/internal/sql/ast/create_publication_stmt.go
index 5d0b6a05f5..90e0c737af 100644
--- a/internal/sql/ast/create_publication_stmt.go
+++ b/internal/sql/ast/create_publication_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreatePublicationStmt struct {
-	Pubname      *string
-	Options      *List
-	Tables       *List
-	ForAllTables bool
+	Tag NodeTag[CreatePublicationStmt] `json:"tag"`
+
+	Pubname      *string `json:"pubname,omitempty"`
+	Options      *List   `json:"options,omitempty"`
+	Tables       *List   `json:"tables,omitempty"`
+	ForAllTables bool    `json:"for_all_tables"`
 }
 
 func (n *CreatePublicationStmt) Pos() int {
diff --git a/internal/sql/ast/create_range_stmt.go b/internal/sql/ast/create_range_stmt.go
index 6e0aaa5092..7ac3b8a353 100644
--- a/internal/sql/ast/create_range_stmt.go
+++ b/internal/sql/ast/create_range_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CreateRangeStmt struct {
-	TypeName *List
-	Params   *List
+	Tag NodeTag[CreateRangeStmt] `json:"tag"`
+
+	TypeName *List `json:"type_name,omitempty"`
+	Params   *List `json:"params,omitempty"`
 }
 
 func (n *CreateRangeStmt) Pos() int {
diff --git a/internal/sql/ast/create_role_stmt.go b/internal/sql/ast/create_role_stmt.go
index 144540863e..667d702dd9 100644
--- a/internal/sql/ast/create_role_stmt.go
+++ b/internal/sql/ast/create_role_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type CreateRoleStmt struct {
-	StmtType RoleStmtType
-	Role     *string
-	Options  *List
+	Tag NodeTag[CreateRoleStmt] `json:"tag"`
+
+	StmtType RoleStmtType `json:"stmt_type"`
+	Role     *string      `json:"role,omitempty"`
+	Options  *List        `json:"options,omitempty"`
 }
 
 func (n *CreateRoleStmt) Pos() int {
diff --git a/internal/sql/ast/create_schema_stmt.go b/internal/sql/ast/create_schema_stmt.go
index 522f404ec4..e07dafaffd 100644
--- a/internal/sql/ast/create_schema_stmt.go
+++ b/internal/sql/ast/create_schema_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreateSchemaStmt struct {
-	Name        *string
-	SchemaElts  *List
-	Authrole    *RoleSpec
-	IfNotExists bool
+	Tag NodeTag[CreateSchemaStmt] `json:"tag"`
+
+	Name        *string   `json:"name,omitempty"`
+	SchemaElts  *List     `json:"schema_elts,omitempty"`
+	Authrole    *RoleSpec `json:"authrole,omitempty"`
+	IfNotExists bool      `json:"if_not_exists"`
 }
 
 func (n *CreateSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/create_seq_stmt.go b/internal/sql/ast/create_seq_stmt.go
index f7b9ef564d..66c35a7080 100644
--- a/internal/sql/ast/create_seq_stmt.go
+++ b/internal/sql/ast/create_seq_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type CreateSeqStmt struct {
-	Sequence    *RangeVar
-	Options     *List
-	OwnerId     Oid
-	ForIdentity bool
-	IfNotExists bool
+	Tag NodeTag[CreateSeqStmt] `json:"tag"`
+
+	Sequence    *RangeVar `json:"sequence,omitempty"`
+	Options     *List     `json:"options,omitempty"`
+	OwnerId     Oid       `json:"owner_id"`
+	ForIdentity bool      `json:"for_identity"`
+	IfNotExists bool      `json:"if_not_exists"`
 }
 
 func (n *CreateSeqStmt) Pos() int {
diff --git a/internal/sql/ast/create_stats_stmt.go b/internal/sql/ast/create_stats_stmt.go
index 4bd64e162c..17b8af22a3 100644
--- a/internal/sql/ast/create_stats_stmt.go
+++ b/internal/sql/ast/create_stats_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type CreateStatsStmt struct {
-	Defnames    *List
-	StatTypes   *List
-	Exprs       *List
-	Relations   *List
-	IfNotExists bool
+	Tag NodeTag[CreateStatsStmt] `json:"tag"`
+
+	Defnames    *List `json:"defnames,omitempty"`
+	StatTypes   *List `json:"stat_types,omitempty"`
+	Exprs       *List `json:"exprs,omitempty"`
+	Relations   *List `json:"relations,omitempty"`
+	IfNotExists bool  `json:"if_not_exists"`
 }
 
 func (n *CreateStatsStmt) Pos() int {
diff --git a/internal/sql/ast/create_stmt.go b/internal/sql/ast/create_stmt.go
index 7982b690a2..5d69e7bb16 100644
--- a/internal/sql/ast/create_stmt.go
+++ b/internal/sql/ast/create_stmt.go
@@ -1,17 +1,19 @@
 package ast
 
 type CreateStmt struct {
-	Relation       *RangeVar
-	TableElts      *List
-	InhRelations   *List
-	Partbound      *PartitionBoundSpec
-	Partspec       *PartitionSpec
-	OfTypename     *TypeName
-	Constraints    *List
-	Options        *List
-	Oncommit       OnCommitAction
-	Tablespacename *string
-	IfNotExists    bool
+	Tag NodeTag[CreateStmt] `json:"tag"`
+
+	Relation       *RangeVar           `json:"relation,omitempty"`
+	TableElts      *List               `json:"table_elts,omitempty"`
+	InhRelations   *List               `json:"inh_relations,omitempty"`
+	Partbound      *PartitionBoundSpec `json:"partbound,omitempty"`
+	Partspec       *PartitionSpec      `json:"partspec,omitempty"`
+	OfTypename     *TypeName           `json:"of_typename,omitempty"`
+	Constraints    *List               `json:"constraints,omitempty"`
+	Options        *List               `json:"options,omitempty"`
+	Oncommit       OnCommitAction      `json:"oncommit"`
+	Tablespacename *string             `json:"tablespacename,omitempty"`
+	IfNotExists    bool                `json:"if_not_exists"`
 }
 
 func (n *CreateStmt) Pos() int {
diff --git a/internal/sql/ast/create_subscription_stmt.go b/internal/sql/ast/create_subscription_stmt.go
index 1d7d49c403..d4c3c678a4 100644
--- a/internal/sql/ast/create_subscription_stmt.go
+++ b/internal/sql/ast/create_subscription_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreateSubscriptionStmt struct {
-	Subname     *string
-	Conninfo    *string
-	Publication *List
-	Options     *List
+	Tag NodeTag[CreateSubscriptionStmt] `json:"tag"`
+
+	Subname     *string `json:"subname,omitempty"`
+	Conninfo    *string `json:"conninfo,omitempty"`
+	Publication *List   `json:"publication,omitempty"`
+	Options     *List   `json:"options,omitempty"`
 }
 
 func (n *CreateSubscriptionStmt) Pos() int {
diff --git a/internal/sql/ast/create_table_as_stmt.go b/internal/sql/ast/create_table_as_stmt.go
index 6dbf291de4..862d0c45d0 100644
--- a/internal/sql/ast/create_table_as_stmt.go
+++ b/internal/sql/ast/create_table_as_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type CreateTableAsStmt struct {
-	Query        Node
-	Into         *IntoClause
-	Relkind      ObjectType
-	IsSelectInto bool
-	IfNotExists  bool
+	Tag NodeTag[CreateTableAsStmt] `json:"tag"`
+
+	Query        Node        `json:"query,omitempty"`
+	Into         *IntoClause `json:"into,omitempty"`
+	Relkind      ObjectType  `json:"relkind"`
+	IsSelectInto bool        `json:"is_select_into"`
+	IfNotExists  bool        `json:"if_not_exists"`
 }
 
 func (n *CreateTableAsStmt) Pos() int {
diff --git a/internal/sql/ast/create_table_space_stmt.go b/internal/sql/ast/create_table_space_stmt.go
index 92951572d3..7c55d5d86a 100644
--- a/internal/sql/ast/create_table_space_stmt.go
+++ b/internal/sql/ast/create_table_space_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreateTableSpaceStmt struct {
-	Tablespacename *string
-	Owner          *RoleSpec
-	Location       *string
-	Options        *List
+	Tag NodeTag[CreateTableSpaceStmt] `json:"tag"`
+
+	Tablespacename *string   `json:"tablespacename,omitempty"`
+	Owner          *RoleSpec `json:"owner,omitempty"`
+	Location       *string   `json:"location,omitempty"`
+	Options        *List     `json:"options,omitempty"`
 }
 
 func (n *CreateTableSpaceStmt) Pos() int {
diff --git a/internal/sql/ast/create_table_stmt.go b/internal/sql/ast/create_table_stmt.go
index cd11c61fac..4abe5d09fb 100644
--- a/internal/sql/ast/create_table_stmt.go
+++ b/internal/sql/ast/create_table_stmt.go
@@ -3,12 +3,14 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type CreateTableStmt struct {
-	IfNotExists bool
-	Name        *TableName
-	Cols        []*ColumnDef
-	ReferTable  *TableName
-	Comment     string
-	Inherits    []*TableName
+	Tag NodeTag[CreateTableStmt] `json:"tag"`
+
+	IfNotExists bool         `json:"if_not_exists"`
+	Name        *TableName   `json:"name,omitempty"`
+	Cols        []*ColumnDef `json:"cols,omitempty"`
+	ReferTable  *TableName   `json:"refer_table,omitempty"`
+	Comment     string       `json:"comment"`
+	Inherits    []*TableName `json:"inherits,omitempty"`
 	// Using names the module of a virtual table (SQLite's CREATE VIRTUAL
 	// TABLE ... USING module(...)), and ModuleArgs carries the module's
 	// argument list as written — its grammar belongs to the module, so the
@@ -16,18 +18,18 @@ type CreateTableStmt struct {
 	// argument list at all. Cols still holds the columns sqlc derives from
 	// the arguments for the catalog; the statement prints as its
 	// declaration, not as those columns.
-	Using      string
-	ModuleArgs []string
+	Using      string   `json:"using"`
+	ModuleArgs []string `json:"module_args,omitempty"`
 	// ModuleArgsMultiline records that the declaration was written across
 	// lines. The arguments carry no positions, so the printer cannot keep
 	// the author's exact breaks and prints the canonical broken form — one
 	// argument per line — instead.
-	ModuleArgsMultiline bool
+	ModuleArgsMultiline bool `json:"module_args_multiline"`
 	// Incomplete marks a statement whose source carried syntax this node
 	// does not model — column or table constraints beyond plain NOT NULL
 	// and PRIMARY KEY, table options, TEMP, or an AS SELECT body. No
 	// faithful rendering exists for it.
-	Incomplete bool
+	Incomplete bool `json:"incomplete"`
 }
 
 func (n *CreateTableStmt) Pos() int {
diff --git a/internal/sql/ast/create_transform_stmt.go b/internal/sql/ast/create_transform_stmt.go
index ef83e2c49a..20b0c633fc 100644
--- a/internal/sql/ast/create_transform_stmt.go
+++ b/internal/sql/ast/create_transform_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type CreateTransformStmt struct {
-	Replace  bool
-	TypeName *TypeName
-	Lang     *string
-	Fromsql  *ObjectWithArgs
-	Tosql    *ObjectWithArgs
+	Tag NodeTag[CreateTransformStmt] `json:"tag"`
+
+	Replace  bool            `json:"replace"`
+	TypeName *TypeName       `json:"type_name,omitempty"`
+	Lang     *string         `json:"lang,omitempty"`
+	Fromsql  *ObjectWithArgs `json:"fromsql,omitempty"`
+	Tosql    *ObjectWithArgs `json:"tosql,omitempty"`
 }
 
 func (n *CreateTransformStmt) Pos() int {
diff --git a/internal/sql/ast/create_trig_stmt.go b/internal/sql/ast/create_trig_stmt.go
index acecce084c..b0c81d6891 100644
--- a/internal/sql/ast/create_trig_stmt.go
+++ b/internal/sql/ast/create_trig_stmt.go
@@ -1,20 +1,22 @@
 package ast
 
 type CreateTrigStmt struct {
-	Trigname       *string
-	Relation       *RangeVar
-	Funcname       *List
-	Args           *List
-	Row            bool
-	Timing         int16
-	Events         int16
-	Columns        *List
-	WhenClause     Node
-	Isconstraint   bool
-	TransitionRels *List
-	Deferrable     bool
-	Initdeferred   bool
-	Constrrel      *RangeVar
+	Tag NodeTag[CreateTrigStmt] `json:"tag"`
+
+	Trigname       *string   `json:"trigname,omitempty"`
+	Relation       *RangeVar `json:"relation,omitempty"`
+	Funcname       *List     `json:"funcname,omitempty"`
+	Args           *List     `json:"args,omitempty"`
+	Row            bool      `json:"row"`
+	Timing         int16     `json:"timing"`
+	Events         int16     `json:"events"`
+	Columns        *List     `json:"columns,omitempty"`
+	WhenClause     Node      `json:"when_clause,omitempty"`
+	Isconstraint   bool      `json:"isconstraint"`
+	TransitionRels *List     `json:"transition_rels,omitempty"`
+	Deferrable     bool      `json:"deferrable"`
+	Initdeferred   bool      `json:"initdeferred"`
+	Constrrel      *RangeVar `json:"constrrel,omitempty"`
 }
 
 func (n *CreateTrigStmt) Pos() int {
diff --git a/internal/sql/ast/create_user_mapping_stmt.go b/internal/sql/ast/create_user_mapping_stmt.go
index f5fd41f76c..e67bd62302 100644
--- a/internal/sql/ast/create_user_mapping_stmt.go
+++ b/internal/sql/ast/create_user_mapping_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type CreateUserMappingStmt struct {
-	User        *RoleSpec
-	Servername  *string
-	IfNotExists bool
-	Options     *List
+	Tag NodeTag[CreateUserMappingStmt] `json:"tag"`
+
+	User        *RoleSpec `json:"user,omitempty"`
+	Servername  *string   `json:"servername,omitempty"`
+	IfNotExists bool      `json:"if_not_exists"`
+	Options     *List     `json:"options,omitempty"`
 }
 
 func (n *CreateUserMappingStmt) Pos() int {
diff --git a/internal/sql/ast/createdb_stmt.go b/internal/sql/ast/createdb_stmt.go
index 114505862d..ee08567a07 100644
--- a/internal/sql/ast/createdb_stmt.go
+++ b/internal/sql/ast/createdb_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type CreatedbStmt struct {
-	Dbname  *string
-	Options *List
+	Tag NodeTag[CreatedbStmt] `json:"tag"`
+
+	Dbname  *string `json:"dbname,omitempty"`
+	Options *List   `json:"options,omitempty"`
 }
 
 func (n *CreatedbStmt) Pos() int {
diff --git a/internal/sql/ast/current_of_expr.go b/internal/sql/ast/current_of_expr.go
index 88b457f8d2..ac9eb35b3f 100644
--- a/internal/sql/ast/current_of_expr.go
+++ b/internal/sql/ast/current_of_expr.go
@@ -1,10 +1,12 @@
 package ast
 
 type CurrentOfExpr struct {
-	Xpr         Node
-	Cvarno      Index
-	CursorName  *string
-	CursorParam int
+	Tag NodeTag[CurrentOfExpr] `json:"tag"`
+
+	Xpr         Node    `json:"xpr,omitempty"`
+	Cvarno      Index   `json:"cvarno"`
+	CursorName  *string `json:"cursor_name,omitempty"`
+	CursorParam int     `json:"cursor_param"`
 }
 
 func (n *CurrentOfExpr) Pos() int {
diff --git a/internal/sql/ast/deallocate_stmt.go b/internal/sql/ast/deallocate_stmt.go
index b11807b57b..c51908fb82 100644
--- a/internal/sql/ast/deallocate_stmt.go
+++ b/internal/sql/ast/deallocate_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type DeallocateStmt struct {
-	Name *string
+	Tag NodeTag[DeallocateStmt] `json:"tag"`
+
+	Name *string `json:"name,omitempty"`
 }
 
 func (n *DeallocateStmt) Pos() int {
diff --git a/internal/sql/ast/declare_cursor_stmt.go b/internal/sql/ast/declare_cursor_stmt.go
index 82b0e6a2e0..52c8a226d5 100644
--- a/internal/sql/ast/declare_cursor_stmt.go
+++ b/internal/sql/ast/declare_cursor_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type DeclareCursorStmt struct {
-	Portalname *string
-	Options    int
-	Query      Node
+	Tag NodeTag[DeclareCursorStmt] `json:"tag"`
+
+	Portalname *string `json:"portalname,omitempty"`
+	Options    int     `json:"options"`
+	Query      Node    `json:"query,omitempty"`
 }
 
 func (n *DeclareCursorStmt) Pos() int {
diff --git a/internal/sql/ast/def_elem.go b/internal/sql/ast/def_elem.go
index 33aacaaa03..9ccf44366a 100644
--- a/internal/sql/ast/def_elem.go
+++ b/internal/sql/ast/def_elem.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type DefElem struct {
-	Defnamespace *string
-	Defname      *string
-	Arg          Node
-	Defaction    DefElemAction
-	Location     int
+	Tag NodeTag[DefElem] `json:"tag"`
+
+	Defnamespace *string       `json:"defnamespace,omitempty"`
+	Defname      *string       `json:"defname,omitempty"`
+	Arg          Node          `json:"arg,omitempty"`
+	Defaction    DefElemAction `json:"defaction"`
+	Location     int           `json:"location"`
 }
 
 func (n *DefElem) Pos() int {
diff --git a/internal/sql/ast/define_stmt.go b/internal/sql/ast/define_stmt.go
index 3860183d7e..9ac5e7a1e8 100644
--- a/internal/sql/ast/define_stmt.go
+++ b/internal/sql/ast/define_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type DefineStmt struct {
-	Kind        ObjectType
-	Oldstyle    bool
-	Defnames    *List
-	Args        *List
-	Definition  *List
-	IfNotExists bool
+	Tag NodeTag[DefineStmt] `json:"tag"`
+
+	Kind        ObjectType `json:"kind"`
+	Oldstyle    bool       `json:"oldstyle"`
+	Defnames    *List      `json:"defnames,omitempty"`
+	Args        *List      `json:"args,omitempty"`
+	Definition  *List      `json:"definition,omitempty"`
+	IfNotExists bool       `json:"if_not_exists"`
 }
 
 func (n *DefineStmt) Pos() int {
diff --git a/internal/sql/ast/delete_stmt.go b/internal/sql/ast/delete_stmt.go
index 318713ad6c..5d584b6d0c 100644
--- a/internal/sql/ast/delete_stmt.go
+++ b/internal/sql/ast/delete_stmt.go
@@ -3,18 +3,20 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type DeleteStmt struct {
-	Relations     *List
-	UsingClause   *List
-	WhereClause   Node
-	LimitCount    Node
-	ReturningList *List
-	WithClause    *WithClause
+	Tag NodeTag[DeleteStmt] `json:"tag"`
+
+	Relations     *List       `json:"relations,omitempty"`
+	UsingClause   *List       `json:"using_clause,omitempty"`
+	WhereClause   Node        `json:"where_clause,omitempty"`
+	LimitCount    Node        `json:"limit_count,omitempty"`
+	ReturningList *List       `json:"returning_list,omitempty"`
+	WithClause    *WithClause `json:"with_clause,omitempty"`
 	// MySQL multi-table DELETE support
-	Targets    *List // Tables to delete from (e.g., jt.*, pt.*)
-	FromClause Node  // FROM clause with JOINs (Node to support JoinExpr)
+	Targets    *List `json:"targets,omitempty"`     // Tables to delete from (e.g., jt.*, pt.*)
+	FromClause Node  `json:"from_clause,omitempty"` // FROM clause with JOINs (Node to support JoinExpr)
 	// PostgreSQL 18 RETURNING WITH (OLD AS ..., NEW AS ...) aliases
-	ReturningOldAlias string
-	ReturningNewAlias string
+	ReturningOldAlias string `json:"returning_old_alias"`
+	ReturningNewAlias string `json:"returning_new_alias"`
 }
 
 func (n *DeleteStmt) Pos() int {
diff --git a/internal/sql/ast/discard_stmt.go b/internal/sql/ast/discard_stmt.go
index 9c731df1fb..6831f7df81 100644
--- a/internal/sql/ast/discard_stmt.go
+++ b/internal/sql/ast/discard_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type DiscardStmt struct {
-	Target DiscardMode
+	Tag NodeTag[DiscardStmt] `json:"tag"`
+
+	Target DiscardMode `json:"target"`
 }
 
 func (n *DiscardStmt) Pos() int {
diff --git a/internal/sql/ast/do_stmt.go b/internal/sql/ast/do_stmt.go
index 9becfb8e64..f21bafe8c5 100644
--- a/internal/sql/ast/do_stmt.go
+++ b/internal/sql/ast/do_stmt.go
@@ -3,7 +3,9 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type DoStmt struct {
-	Args *List
+	Tag NodeTag[DoStmt] `json:"tag"`
+
+	Args *List `json:"args,omitempty"`
 }
 
 func (n *DoStmt) Pos() int {
diff --git a/internal/sql/ast/drop_function_stmt.go b/internal/sql/ast/drop_function_stmt.go
index c1b10b95c1..e5fec40469 100644
--- a/internal/sql/ast/drop_function_stmt.go
+++ b/internal/sql/ast/drop_function_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropFunctionStmt struct {
-	Funcs     []*FuncSpec
-	MissingOk bool
+	Tag NodeTag[DropFunctionStmt] `json:"tag"`
+
+	Funcs     []*FuncSpec `json:"funcs,omitempty"`
+	MissingOk bool        `json:"missing_ok"`
 }
 
 func (n *DropFunctionStmt) Pos() int {
diff --git a/internal/sql/ast/drop_owned_stmt.go b/internal/sql/ast/drop_owned_stmt.go
index 5826c33bbc..ab988187a0 100644
--- a/internal/sql/ast/drop_owned_stmt.go
+++ b/internal/sql/ast/drop_owned_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropOwnedStmt struct {
-	Roles    *List
-	Behavior DropBehavior
+	Tag NodeTag[DropOwnedStmt] `json:"tag"`
+
+	Roles    *List        `json:"roles,omitempty"`
+	Behavior DropBehavior `json:"behavior"`
 }
 
 func (n *DropOwnedStmt) Pos() int {
diff --git a/internal/sql/ast/drop_role_stmt.go b/internal/sql/ast/drop_role_stmt.go
index 95bd26a671..2bdcffd2ab 100644
--- a/internal/sql/ast/drop_role_stmt.go
+++ b/internal/sql/ast/drop_role_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropRoleStmt struct {
-	Roles     *List
-	MissingOk bool
+	Tag NodeTag[DropRoleStmt] `json:"tag"`
+
+	Roles     *List `json:"roles,omitempty"`
+	MissingOk bool  `json:"missing_ok"`
 }
 
 func (n *DropRoleStmt) Pos() int {
diff --git a/internal/sql/ast/drop_schema_stmt.go b/internal/sql/ast/drop_schema_stmt.go
index 8b7bad5180..f5d9f1e7ca 100644
--- a/internal/sql/ast/drop_schema_stmt.go
+++ b/internal/sql/ast/drop_schema_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropSchemaStmt struct {
-	Schemas   []*String
-	MissingOk bool
+	Tag NodeTag[DropSchemaStmt] `json:"tag"`
+
+	Schemas   []*String `json:"schemas,omitempty"`
+	MissingOk bool      `json:"missing_ok"`
 }
 
 func (n *DropSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/drop_stmt.go b/internal/sql/ast/drop_stmt.go
index 9bb7d649a0..3305e16bf5 100644
--- a/internal/sql/ast/drop_stmt.go
+++ b/internal/sql/ast/drop_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type DropStmt struct {
-	Objects    *List
-	RemoveType ObjectType
-	Behavior   DropBehavior
-	MissingOk  bool
-	Concurrent bool
+	Tag NodeTag[DropStmt] `json:"tag"`
+
+	Objects    *List        `json:"objects,omitempty"`
+	RemoveType ObjectType   `json:"remove_type"`
+	Behavior   DropBehavior `json:"behavior"`
+	MissingOk  bool         `json:"missing_ok"`
+	Concurrent bool         `json:"concurrent"`
 }
 
 func (n *DropStmt) Pos() int {
diff --git a/internal/sql/ast/drop_subscription_stmt.go b/internal/sql/ast/drop_subscription_stmt.go
index 7b8b025ac6..3fbd8528e4 100644
--- a/internal/sql/ast/drop_subscription_stmt.go
+++ b/internal/sql/ast/drop_subscription_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type DropSubscriptionStmt struct {
-	Subname   *string
-	MissingOk bool
-	Behavior  DropBehavior
+	Tag NodeTag[DropSubscriptionStmt] `json:"tag"`
+
+	Subname   *string      `json:"subname,omitempty"`
+	MissingOk bool         `json:"missing_ok"`
+	Behavior  DropBehavior `json:"behavior"`
 }
 
 func (n *DropSubscriptionStmt) Pos() int {
diff --git a/internal/sql/ast/drop_table_space_stmt.go b/internal/sql/ast/drop_table_space_stmt.go
index bf96094d80..8093e7331c 100644
--- a/internal/sql/ast/drop_table_space_stmt.go
+++ b/internal/sql/ast/drop_table_space_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropTableSpaceStmt struct {
-	Tablespacename *string
-	MissingOk      bool
+	Tag NodeTag[DropTableSpaceStmt] `json:"tag"`
+
+	Tablespacename *string `json:"tablespacename,omitempty"`
+	MissingOk      bool    `json:"missing_ok"`
 }
 
 func (n *DropTableSpaceStmt) Pos() int {
diff --git a/internal/sql/ast/drop_table_stmt.go b/internal/sql/ast/drop_table_stmt.go
index 7485ceb887..4687b7cbe3 100644
--- a/internal/sql/ast/drop_table_stmt.go
+++ b/internal/sql/ast/drop_table_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropTableStmt struct {
-	IfExists bool
-	Tables   []*TableName
+	Tag NodeTag[DropTableStmt] `json:"tag"`
+
+	IfExists bool         `json:"if_exists"`
+	Tables   []*TableName `json:"tables,omitempty"`
 }
 
 func (n *DropTableStmt) Pos() int {
diff --git a/internal/sql/ast/drop_type_stmt.go b/internal/sql/ast/drop_type_stmt.go
index 3aa0401b19..dcef895f1b 100644
--- a/internal/sql/ast/drop_type_stmt.go
+++ b/internal/sql/ast/drop_type_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropTypeStmt struct {
-	IfExists bool
-	Types    []*TypeName
+	Tag NodeTag[DropTypeStmt] `json:"tag"`
+
+	IfExists bool        `json:"if_exists"`
+	Types    []*TypeName `json:"types,omitempty"`
 }
 
 func (n *DropTypeStmt) Pos() int {
diff --git a/internal/sql/ast/drop_user_mapping_stmt.go b/internal/sql/ast/drop_user_mapping_stmt.go
index f5852c708f..9503d8a259 100644
--- a/internal/sql/ast/drop_user_mapping_stmt.go
+++ b/internal/sql/ast/drop_user_mapping_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type DropUserMappingStmt struct {
-	User       *RoleSpec
-	Servername *string
-	MissingOk  bool
+	Tag NodeTag[DropUserMappingStmt] `json:"tag"`
+
+	User       *RoleSpec `json:"user,omitempty"`
+	Servername *string   `json:"servername,omitempty"`
+	MissingOk  bool      `json:"missing_ok"`
 }
 
 func (n *DropUserMappingStmt) Pos() int {
diff --git a/internal/sql/ast/dropdb_stmt.go b/internal/sql/ast/dropdb_stmt.go
index 62a0c47346..da6eb860bb 100644
--- a/internal/sql/ast/dropdb_stmt.go
+++ b/internal/sql/ast/dropdb_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type DropdbStmt struct {
-	Dbname    *string
-	MissingOk bool
+	Tag NodeTag[DropdbStmt] `json:"tag"`
+
+	Dbname    *string `json:"dbname,omitempty"`
+	MissingOk bool    `json:"missing_ok"`
 }
 
 func (n *DropdbStmt) Pos() int {
diff --git a/internal/sql/ast/execute_stmt.go b/internal/sql/ast/execute_stmt.go
index 92a237141d..4ede4f42ca 100644
--- a/internal/sql/ast/execute_stmt.go
+++ b/internal/sql/ast/execute_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type ExecuteStmt struct {
-	Name   *string
-	Params *List
+	Tag NodeTag[ExecuteStmt] `json:"tag"`
+
+	Name   *string `json:"name,omitempty"`
+	Params *List   `json:"params,omitempty"`
 }
 
 func (n *ExecuteStmt) Pos() int {
diff --git a/internal/sql/ast/explain_stmt.go b/internal/sql/ast/explain_stmt.go
index 1d78aa815a..66c5608035 100644
--- a/internal/sql/ast/explain_stmt.go
+++ b/internal/sql/ast/explain_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type ExplainStmt struct {
-	Query   Node
-	Options *List
+	Tag NodeTag[ExplainStmt] `json:"tag"`
+
+	Query   Node  `json:"query,omitempty"`
+	Options *List `json:"options,omitempty"`
 }
 
 func (n *ExplainStmt) Pos() int {
diff --git a/internal/sql/ast/expr.go b/internal/sql/ast/expr.go
index a054970ccf..4de58b5214 100644
--- a/internal/sql/ast/expr.go
+++ b/internal/sql/ast/expr.go
@@ -1,6 +1,7 @@
 package ast
 
 type Expr struct {
+	Tag NodeTag[Expr] `json:"tag"`
 }
 
 func (n *Expr) Pos() int {
diff --git a/internal/sql/ast/fetch_stmt.go b/internal/sql/ast/fetch_stmt.go
index cd43ef19ed..7a59569e37 100644
--- a/internal/sql/ast/fetch_stmt.go
+++ b/internal/sql/ast/fetch_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type FetchStmt struct {
-	Direction  FetchDirection
-	HowMany    int64
-	Portalname *string
-	Ismove     bool
+	Tag NodeTag[FetchStmt] `json:"tag"`
+
+	Direction  FetchDirection `json:"direction"`
+	HowMany    int64          `json:"how_many"`
+	Portalname *string        `json:"portalname,omitempty"`
+	Ismove     bool           `json:"ismove"`
 }
 
 func (n *FetchStmt) Pos() int {
diff --git a/internal/sql/ast/field_select.go b/internal/sql/ast/field_select.go
index 347abd44bf..57f77a6794 100644
--- a/internal/sql/ast/field_select.go
+++ b/internal/sql/ast/field_select.go
@@ -1,12 +1,14 @@
 package ast
 
 type FieldSelect struct {
-	Xpr          Node
-	Arg          Node
-	Fieldnum     AttrNumber
-	Resulttype   Oid
-	Resulttypmod int32
-	Resultcollid Oid
+	Tag NodeTag[FieldSelect] `json:"tag"`
+
+	Xpr          Node       `json:"xpr,omitempty"`
+	Arg          Node       `json:"arg,omitempty"`
+	Fieldnum     AttrNumber `json:"fieldnum"`
+	Resulttype   Oid        `json:"resulttype"`
+	Resulttypmod int32      `json:"resulttypmod"`
+	Resultcollid Oid        `json:"resultcollid"`
 }
 
 func (n *FieldSelect) Pos() int {
diff --git a/internal/sql/ast/field_store.go b/internal/sql/ast/field_store.go
index 6c2cfc230c..505c924a9c 100644
--- a/internal/sql/ast/field_store.go
+++ b/internal/sql/ast/field_store.go
@@ -1,11 +1,13 @@
 package ast
 
 type FieldStore struct {
-	Xpr        Node
-	Arg        Node
-	Newvals    *List
-	Fieldnums  *List
-	Resulttype Oid
+	Tag NodeTag[FieldStore] `json:"tag"`
+
+	Xpr        Node  `json:"xpr,omitempty"`
+	Arg        Node  `json:"arg,omitempty"`
+	Newvals    *List `json:"newvals,omitempty"`
+	Fieldnums  *List `json:"fieldnums,omitempty"`
+	Resulttype Oid   `json:"resulttype"`
 }
 
 func (n *FieldStore) Pos() int {
diff --git a/internal/sql/ast/float.go b/internal/sql/ast/float.go
index 94e8c2652f..a91b89a273 100644
--- a/internal/sql/ast/float.go
+++ b/internal/sql/ast/float.go
@@ -3,7 +3,9 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type Float struct {
-	Str string
+	Tag NodeTag[Float] `json:"tag"`
+
+	Str string `json:"str"`
 }
 
 func (n *Float) Pos() int {
diff --git a/internal/sql/ast/from_expr.go b/internal/sql/ast/from_expr.go
index deb93da4a4..021ac30cf8 100644
--- a/internal/sql/ast/from_expr.go
+++ b/internal/sql/ast/from_expr.go
@@ -1,8 +1,10 @@
 package ast
 
 type FromExpr struct {
-	Fromlist *List
-	Quals    Node
+	Tag NodeTag[FromExpr] `json:"tag"`
+
+	Fromlist *List `json:"fromlist,omitempty"`
+	Quals    Node  `json:"quals,omitempty"`
 }
 
 func (n *FromExpr) Pos() int {
diff --git a/internal/sql/ast/func_call.go b/internal/sql/ast/func_call.go
index cb4f210fe4..f7e041f3cd 100644
--- a/internal/sql/ast/func_call.go
+++ b/internal/sql/ast/func_call.go
@@ -3,18 +3,20 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type FuncCall struct {
-	Func           *FuncName
-	Funcname       *List
-	Args           *List
-	AggOrder       *List
-	AggFilter      Node
-	AggWithinGroup bool
-	AggStar        bool
-	AggDistinct    bool
-	FuncVariadic   bool
-	Over           *WindowDef
-	Separator      *string // MySQL GROUP_CONCAT SEPARATOR
-	Location       int
+	Tag NodeTag[FuncCall] `json:"tag"`
+
+	Func           *FuncName  `json:"func,omitempty"`
+	Funcname       *List      `json:"funcname,omitempty"`
+	Args           *List      `json:"args,omitempty"`
+	AggOrder       *List      `json:"agg_order,omitempty"`
+	AggFilter      Node       `json:"agg_filter,omitempty"`
+	AggWithinGroup bool       `json:"agg_within_group"`
+	AggStar        bool       `json:"agg_star"`
+	AggDistinct    bool       `json:"agg_distinct"`
+	FuncVariadic   bool       `json:"func_variadic"`
+	Over           *WindowDef `json:"over,omitempty"`
+	Separator      *string    `json:"separator,omitempty"` // MySQL GROUP_CONCAT SEPARATOR
+	Location       int        `json:"location"`
 }
 
 func (n *FuncCall) Pos() int {
diff --git a/internal/sql/ast/func_expr.go b/internal/sql/ast/func_expr.go
index e571a63049..39dee6f0ae 100644
--- a/internal/sql/ast/func_expr.go
+++ b/internal/sql/ast/func_expr.go
@@ -1,16 +1,18 @@
 package ast
 
 type FuncExpr struct {
-	Xpr            Node
-	Funcid         Oid
-	Funcresulttype Oid
-	Funcretset     bool
-	Funcvariadic   bool
-	Funcformat     CoercionForm
-	Funccollid     Oid
-	Inputcollid    Oid
-	Args           *List
-	Location       int
+	Tag NodeTag[FuncExpr] `json:"tag"`
+
+	Xpr            Node         `json:"xpr,omitempty"`
+	Funcid         Oid          `json:"funcid"`
+	Funcresulttype Oid          `json:"funcresulttype"`
+	Funcretset     bool         `json:"funcretset"`
+	Funcvariadic   bool         `json:"funcvariadic"`
+	Funcformat     CoercionForm `json:"funcformat"`
+	Funccollid     Oid          `json:"funccollid"`
+	Inputcollid    Oid          `json:"inputcollid"`
+	Args           *List        `json:"args,omitempty"`
+	Location       int          `json:"location"`
 }
 
 func (n *FuncExpr) Pos() int {
diff --git a/internal/sql/ast/func_name.go b/internal/sql/ast/func_name.go
index cdf3e23d33..0c1d6fb7a3 100644
--- a/internal/sql/ast/func_name.go
+++ b/internal/sql/ast/func_name.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type FuncName struct {
-	Catalog string
-	Schema  string
-	Name    string
+	Tag NodeTag[FuncName] `json:"tag"`
+
+	Catalog string `json:"catalog"`
+	Schema  string `json:"schema"`
+	Name    string `json:"name"`
 }
 
 func (n *FuncName) Pos() int {
diff --git a/internal/sql/ast/func_param.go b/internal/sql/ast/func_param.go
index 5881a1441f..ae353f36d9 100644
--- a/internal/sql/ast/func_param.go
+++ b/internal/sql/ast/func_param.go
@@ -14,10 +14,12 @@ const (
 )
 
 type FuncParam struct {
-	Name    *string
-	Type    *TypeName
-	DefExpr Node // Will always be &ast.TODO
-	Mode    FuncParamMode
+	Tag NodeTag[FuncParam] `json:"tag"`
+
+	Name    *string       `json:"name,omitempty"`
+	Type    *TypeName     `json:"type,omitempty"`
+	DefExpr Node          `json:"def_expr,omitempty"` // Will always be &ast.TODO
+	Mode    FuncParamMode `json:"mode"`
 }
 
 func (n *FuncParam) Pos() int {
diff --git a/internal/sql/ast/func_spec.go b/internal/sql/ast/func_spec.go
index f9d4bb40c6..019bac9218 100644
--- a/internal/sql/ast/func_spec.go
+++ b/internal/sql/ast/func_spec.go
@@ -1,9 +1,11 @@
 package ast
 
 type FuncSpec struct {
-	Name    *FuncName
-	Args    []*TypeName
-	HasArgs bool
+	Tag NodeTag[FuncSpec] `json:"tag"`
+
+	Name    *FuncName   `json:"name,omitempty"`
+	Args    []*TypeName `json:"args,omitempty"`
+	HasArgs bool        `json:"has_args"`
 }
 
 func (n *FuncSpec) Pos() int {
diff --git a/internal/sql/ast/function_parameter.go b/internal/sql/ast/function_parameter.go
index 54262f6130..3bbb086713 100644
--- a/internal/sql/ast/function_parameter.go
+++ b/internal/sql/ast/function_parameter.go
@@ -1,10 +1,12 @@
 package ast
 
 type FunctionParameter struct {
-	Name    *string
-	ArgType *TypeName
-	Mode    FunctionParameterMode
-	Defexpr Node
+	Tag NodeTag[FunctionParameter] `json:"tag"`
+
+	Name    *string               `json:"name,omitempty"`
+	ArgType *TypeName             `json:"arg_type,omitempty"`
+	Mode    FunctionParameterMode `json:"mode"`
+	Defexpr Node                  `json:"defexpr,omitempty"`
 }
 
 func (n *FunctionParameter) Pos() int {
diff --git a/internal/sql/ast/grant_role_stmt.go b/internal/sql/ast/grant_role_stmt.go
index 5e0b2a8e87..0dd26f9cc3 100644
--- a/internal/sql/ast/grant_role_stmt.go
+++ b/internal/sql/ast/grant_role_stmt.go
@@ -1,11 +1,13 @@
 package ast
 
 type GrantRoleStmt struct {
-	GrantedRoles *List
-	GranteeRoles *List
-	IsGrant      bool
-	Grantor      *RoleSpec
-	Behavior     DropBehavior
+	Tag NodeTag[GrantRoleStmt] `json:"tag"`
+
+	GrantedRoles *List        `json:"granted_roles,omitempty"`
+	GranteeRoles *List        `json:"grantee_roles,omitempty"`
+	IsGrant      bool         `json:"is_grant"`
+	Grantor      *RoleSpec    `json:"grantor,omitempty"`
+	Behavior     DropBehavior `json:"behavior"`
 }
 
 func (n *GrantRoleStmt) Pos() int {
diff --git a/internal/sql/ast/grant_stmt.go b/internal/sql/ast/grant_stmt.go
index cbed7911ac..964395c146 100644
--- a/internal/sql/ast/grant_stmt.go
+++ b/internal/sql/ast/grant_stmt.go
@@ -1,14 +1,16 @@
 package ast
 
 type GrantStmt struct {
-	IsGrant     bool
-	Targtype    GrantTargetType
-	Objtype     GrantObjectType
-	Objects     *List
-	Privileges  *List
-	Grantees    *List
-	GrantOption bool
-	Behavior    DropBehavior
+	Tag NodeTag[GrantStmt] `json:"tag"`
+
+	IsGrant     bool            `json:"is_grant"`
+	Targtype    GrantTargetType `json:"targtype"`
+	Objtype     GrantObjectType `json:"objtype"`
+	Objects     *List           `json:"objects,omitempty"`
+	Privileges  *List           `json:"privileges,omitempty"`
+	Grantees    *List           `json:"grantees,omitempty"`
+	GrantOption bool            `json:"grant_option"`
+	Behavior    DropBehavior    `json:"behavior"`
 }
 
 func (n *GrantStmt) Pos() int {
diff --git a/internal/sql/ast/grouping_func.go b/internal/sql/ast/grouping_func.go
index 059bfb9dec..80f8471560 100644
--- a/internal/sql/ast/grouping_func.go
+++ b/internal/sql/ast/grouping_func.go
@@ -1,12 +1,14 @@
 package ast
 
 type GroupingFunc struct {
-	Xpr         Node
-	Args        *List
-	Refs        *List
-	Cols        *List
-	Agglevelsup Index
-	Location    int
+	Tag NodeTag[GroupingFunc] `json:"tag"`
+
+	Xpr         Node  `json:"xpr,omitempty"`
+	Args        *List `json:"args,omitempty"`
+	Refs        *List `json:"refs,omitempty"`
+	Cols        *List `json:"cols,omitempty"`
+	Agglevelsup Index `json:"agglevelsup"`
+	Location    int   `json:"location"`
 }
 
 func (n *GroupingFunc) Pos() int {
diff --git a/internal/sql/ast/grouping_set.go b/internal/sql/ast/grouping_set.go
index 32db38a607..10c5098f82 100644
--- a/internal/sql/ast/grouping_set.go
+++ b/internal/sql/ast/grouping_set.go
@@ -1,9 +1,11 @@
 package ast
 
 type GroupingSet struct {
-	Kind     GroupingSetKind
-	Content  *List
-	Location int
+	Tag NodeTag[GroupingSet] `json:"tag"`
+
+	Kind     GroupingSetKind `json:"kind"`
+	Content  *List           `json:"content,omitempty"`
+	Location int             `json:"location"`
 }
 
 func (n *GroupingSet) Pos() int {
diff --git a/internal/sql/ast/import_foreign_schema_stmt.go b/internal/sql/ast/import_foreign_schema_stmt.go
index 6b333f665b..7d824bdbf3 100644
--- a/internal/sql/ast/import_foreign_schema_stmt.go
+++ b/internal/sql/ast/import_foreign_schema_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type ImportForeignSchemaStmt struct {
-	ServerName   *string
-	RemoteSchema *string
-	LocalSchema  *string
-	ListType     ImportForeignSchemaType
-	TableList    *List
-	Options      *List
+	Tag NodeTag[ImportForeignSchemaStmt] `json:"tag"`
+
+	ServerName   *string                 `json:"server_name,omitempty"`
+	RemoteSchema *string                 `json:"remote_schema,omitempty"`
+	LocalSchema  *string                 `json:"local_schema,omitempty"`
+	ListType     ImportForeignSchemaType `json:"list_type"`
+	TableList    *List                   `json:"table_list,omitempty"`
+	Options      *List                   `json:"options,omitempty"`
 }
 
 func (n *ImportForeignSchemaStmt) Pos() int {
diff --git a/internal/sql/ast/in.go b/internal/sql/ast/in.go
index 9bdad67eeb..6afa9fcaf0 100644
--- a/internal/sql/ast/in.go
+++ b/internal/sql/ast/in.go
@@ -4,15 +4,17 @@ import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 // In describes a 'select foo in (bar, baz)' type statement, though there are multiple important variants handled.
 type In struct {
+	Tag NodeTag[In] `json:"tag"`
+
 	// Expr is the value expression to be compared.
-	Expr Node
+	Expr Node `json:"expr,omitempty"`
 	// List is the list expression in compare list.
-	List []Node
+	List []Node `json:"list,omitempty"`
 	// Not is true, the expression is "not in".
-	Not bool
+	Not bool `json:"not"`
 	// Sel is the subquery, may be rewritten to other type of expression.
-	Sel      Node
-	Location int
+	Sel      Node `json:"sel,omitempty"`
+	Location int  `json:"location"`
 }
 
 // Pos returns the location.
diff --git a/internal/sql/ast/index_elem.go b/internal/sql/ast/index_elem.go
index acc2a7fc23..e49ea05c28 100644
--- a/internal/sql/ast/index_elem.go
+++ b/internal/sql/ast/index_elem.go
@@ -3,13 +3,15 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type IndexElem struct {
-	Name          *string
-	Expr          Node
-	Indexcolname  *string
-	Collation     *List
-	Opclass       *List
-	Ordering      SortByDir
-	NullsOrdering SortByNulls
+	Tag NodeTag[IndexElem] `json:"tag"`
+
+	Name          *string     `json:"name,omitempty"`
+	Expr          Node        `json:"expr,omitempty"`
+	Indexcolname  *string     `json:"indexcolname,omitempty"`
+	Collation     *List       `json:"collation,omitempty"`
+	Opclass       *List       `json:"opclass,omitempty"`
+	Ordering      SortByDir   `json:"ordering"`
+	NullsOrdering SortByNulls `json:"nulls_ordering"`
 }
 
 func (n *IndexElem) Pos() int {
diff --git a/internal/sql/ast/index_stmt.go b/internal/sql/ast/index_stmt.go
index fe0f03593c..5eafbcb95f 100644
--- a/internal/sql/ast/index_stmt.go
+++ b/internal/sql/ast/index_stmt.go
@@ -1,24 +1,26 @@
 package ast
 
 type IndexStmt struct {
-	Idxname        *string
-	Relation       *RangeVar
-	AccessMethod   *string
-	TableSpace     *string
-	IndexParams    *List
-	Options        *List
-	WhereClause    Node
-	ExcludeOpNames *List
-	Idxcomment     *string
-	IndexOid       Oid
-	Unique         bool
-	Primary        bool
-	Isconstraint   bool
-	Deferrable     bool
-	Initdeferred   bool
-	Transformed    bool
-	Concurrent     bool
-	IfNotExists    bool
+	Tag NodeTag[IndexStmt] `json:"tag"`
+
+	Idxname        *string   `json:"idxname,omitempty"`
+	Relation       *RangeVar `json:"relation,omitempty"`
+	AccessMethod   *string   `json:"access_method,omitempty"`
+	TableSpace     *string   `json:"table_space,omitempty"`
+	IndexParams    *List     `json:"index_params,omitempty"`
+	Options        *List     `json:"options,omitempty"`
+	WhereClause    Node      `json:"where_clause,omitempty"`
+	ExcludeOpNames *List     `json:"exclude_op_names,omitempty"`
+	Idxcomment     *string   `json:"idxcomment,omitempty"`
+	IndexOid       Oid       `json:"index_oid"`
+	Unique         bool      `json:"unique"`
+	Primary        bool      `json:"primary"`
+	Isconstraint   bool      `json:"isconstraint"`
+	Deferrable     bool      `json:"deferrable"`
+	Initdeferred   bool      `json:"initdeferred"`
+	Transformed    bool      `json:"transformed"`
+	Concurrent     bool      `json:"concurrent"`
+	IfNotExists    bool      `json:"if_not_exists"`
 }
 
 func (n *IndexStmt) Pos() int {
diff --git a/internal/sql/ast/infer_clause.go b/internal/sql/ast/infer_clause.go
index 6df0db4a86..f4dc4bc46d 100644
--- a/internal/sql/ast/infer_clause.go
+++ b/internal/sql/ast/infer_clause.go
@@ -3,10 +3,12 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type InferClause struct {
-	IndexElems  *List
-	WhereClause Node
-	Conname     *string
-	Location    int
+	Tag NodeTag[InferClause] `json:"tag"`
+
+	IndexElems  *List   `json:"index_elems,omitempty"`
+	WhereClause Node    `json:"where_clause,omitempty"`
+	Conname     *string `json:"conname,omitempty"`
+	Location    int     `json:"location"`
 }
 
 func (n *InferClause) Pos() int {
diff --git a/internal/sql/ast/inference_elem.go b/internal/sql/ast/inference_elem.go
index d7b4e091c2..be27eb88a8 100644
--- a/internal/sql/ast/inference_elem.go
+++ b/internal/sql/ast/inference_elem.go
@@ -1,10 +1,12 @@
 package ast
 
 type InferenceElem struct {
-	Xpr          Node
-	Expr         Node
-	Infercollid  Oid
-	Inferopclass Oid
+	Tag NodeTag[InferenceElem] `json:"tag"`
+
+	Xpr          Node `json:"xpr,omitempty"`
+	Expr         Node `json:"expr,omitempty"`
+	Infercollid  Oid  `json:"infercollid"`
+	Inferopclass Oid  `json:"inferopclass"`
 }
 
 func (n *InferenceElem) Pos() int {
diff --git a/internal/sql/ast/inline_code_block.go b/internal/sql/ast/inline_code_block.go
index 91aebcc2e8..6698334d1e 100644
--- a/internal/sql/ast/inline_code_block.go
+++ b/internal/sql/ast/inline_code_block.go
@@ -1,9 +1,11 @@
 package ast
 
 type InlineCodeBlock struct {
-	SourceText    *string
-	LangOid       Oid
-	LangIsTrusted bool
+	Tag NodeTag[InlineCodeBlock] `json:"tag"`
+
+	SourceText    *string `json:"source_text,omitempty"`
+	LangOid       Oid     `json:"lang_oid"`
+	LangIsTrusted bool    `json:"lang_is_trusted"`
 }
 
 func (n *InlineCodeBlock) Pos() int {
diff --git a/internal/sql/ast/insert_stmt.go b/internal/sql/ast/insert_stmt.go
index 6ba9988413..e6d3d3a190 100644
--- a/internal/sql/ast/insert_stmt.go
+++ b/internal/sql/ast/insert_stmt.go
@@ -3,18 +3,20 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type InsertStmt struct {
-	Relation             *RangeVar
-	Cols                 *List
-	SelectStmt           Node
-	OnConflictClause     *OnConflictClause
-	OnDuplicateKeyUpdate *OnDuplicateKeyUpdate // MySQL-specific
-	ReturningList        *List
-	WithClause           *WithClause
-	Override             OverridingKind
-	DefaultValues        bool // SQLite-specific: INSERT INTO ... DEFAULT VALUES
+	Tag NodeTag[InsertStmt] `json:"tag"`
+
+	Relation             *RangeVar             `json:"relation,omitempty"`
+	Cols                 *List                 `json:"cols,omitempty"`
+	SelectStmt           Node                  `json:"select_stmt,omitempty"`
+	OnConflictClause     *OnConflictClause     `json:"on_conflict_clause,omitempty"`
+	OnDuplicateKeyUpdate *OnDuplicateKeyUpdate `json:"on_duplicate_key_update,omitempty"` // MySQL-specific
+	ReturningList        *List                 `json:"returning_list,omitempty"`
+	WithClause           *WithClause           `json:"with_clause,omitempty"`
+	Override             OverridingKind        `json:"override"`
+	DefaultValues        bool                  `json:"default_values"` // SQLite-specific: INSERT INTO ... DEFAULT VALUES
 	// PostgreSQL 18 RETURNING WITH (OLD AS ..., NEW AS ...) aliases
-	ReturningOldAlias string
-	ReturningNewAlias string
+	ReturningOldAlias string `json:"returning_old_alias"`
+	ReturningNewAlias string `json:"returning_new_alias"`
 }
 
 func (n *InsertStmt) Pos() int {
diff --git a/internal/sql/ast/integer.go b/internal/sql/ast/integer.go
index c0c360f2f2..30c270572b 100644
--- a/internal/sql/ast/integer.go
+++ b/internal/sql/ast/integer.go
@@ -7,7 +7,9 @@ import (
 )
 
 type Integer struct {
-	Ival int64
+	Tag NodeTag[Integer] `json:"tag"`
+
+	Ival int64 `json:"ival"`
 }
 
 func (n *Integer) Pos() int {
diff --git a/internal/sql/ast/interval_expr.go b/internal/sql/ast/interval_expr.go
index dac73a0557..f89ceed80c 100644
--- a/internal/sql/ast/interval_expr.go
+++ b/internal/sql/ast/interval_expr.go
@@ -4,9 +4,11 @@ import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 // IntervalExpr represents a MySQL INTERVAL expression like "INTERVAL 1 DAY"
 type IntervalExpr struct {
-	Value    Node
-	Unit     string
-	Location int
+	Tag NodeTag[IntervalExpr] `json:"tag"`
+
+	Value    Node   `json:"value,omitempty"`
+	Unit     string `json:"unit"`
+	Location int    `json:"location"`
 }
 
 func (n *IntervalExpr) Pos() int {
diff --git a/internal/sql/ast/into_clause.go b/internal/sql/ast/into_clause.go
index e460b65ea0..1a74d37bf4 100644
--- a/internal/sql/ast/into_clause.go
+++ b/internal/sql/ast/into_clause.go
@@ -1,13 +1,15 @@
 package ast
 
 type IntoClause struct {
-	Rel            *RangeVar
-	ColNames       *List
-	Options        *List
-	OnCommit       OnCommitAction
-	TableSpaceName *string
-	ViewQuery      Node
-	SkipData       bool
+	Tag NodeTag[IntoClause] `json:"tag"`
+
+	Rel            *RangeVar      `json:"rel,omitempty"`
+	ColNames       *List          `json:"col_names,omitempty"`
+	Options        *List          `json:"options,omitempty"`
+	OnCommit       OnCommitAction `json:"on_commit"`
+	TableSpaceName *string        `json:"table_space_name,omitempty"`
+	ViewQuery      Node           `json:"view_query,omitempty"`
+	SkipData       bool           `json:"skip_data"`
 }
 
 func (n *IntoClause) Pos() int {
diff --git a/internal/sql/ast/join_expr.go b/internal/sql/ast/join_expr.go
index a6bd132d7c..59df9b3aee 100644
--- a/internal/sql/ast/join_expr.go
+++ b/internal/sql/ast/join_expr.go
@@ -3,14 +3,16 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type JoinExpr struct {
-	Jointype    JoinType
-	IsNatural   bool
-	Larg        Node
-	Rarg        Node
-	UsingClause *List
-	Quals       Node
-	Alias       *Alias
-	Rtindex     int
+	Tag NodeTag[JoinExpr] `json:"tag"`
+
+	Jointype    JoinType `json:"jointype"`
+	IsNatural   bool     `json:"is_natural"`
+	Larg        Node     `json:"larg,omitempty"`
+	Rarg        Node     `json:"rarg,omitempty"`
+	UsingClause *List    `json:"using_clause,omitempty"`
+	Quals       Node     `json:"quals,omitempty"`
+	Alias       *Alias   `json:"alias,omitempty"`
+	Rtindex     int      `json:"rtindex"`
 }
 
 func (n *JoinExpr) Pos() int {
diff --git a/internal/sql/ast/list.go b/internal/sql/ast/list.go
index 3bb9d90dcd..86a3fe00dc 100644
--- a/internal/sql/ast/list.go
+++ b/internal/sql/ast/list.go
@@ -3,7 +3,9 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type List struct {
-	Items []Node
+	Tag NodeTag[List] `json:"tag"`
+
+	Items []Node `json:"items,omitempty"`
 }
 
 func (n *List) Pos() int {
diff --git a/internal/sql/ast/listen_stmt.go b/internal/sql/ast/listen_stmt.go
index 48c38419a8..3989225754 100644
--- a/internal/sql/ast/listen_stmt.go
+++ b/internal/sql/ast/listen_stmt.go
@@ -3,7 +3,9 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type ListenStmt struct {
-	Conditionname *string
+	Tag NodeTag[ListenStmt] `json:"tag"`
+
+	Conditionname *string `json:"conditionname,omitempty"`
 }
 
 func (n *ListenStmt) Pos() int {
diff --git a/internal/sql/ast/load_stmt.go b/internal/sql/ast/load_stmt.go
index 1a211fc11a..276f05a134 100644
--- a/internal/sql/ast/load_stmt.go
+++ b/internal/sql/ast/load_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type LoadStmt struct {
-	Filename *string
+	Tag NodeTag[LoadStmt] `json:"tag"`
+
+	Filename *string `json:"filename,omitempty"`
 }
 
 func (n *LoadStmt) Pos() int {
diff --git a/internal/sql/ast/lock_stmt.go b/internal/sql/ast/lock_stmt.go
index 70ec64dce3..82f2481640 100644
--- a/internal/sql/ast/lock_stmt.go
+++ b/internal/sql/ast/lock_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type LockStmt struct {
-	Relations *List
-	Mode      int
-	Nowait    bool
+	Tag NodeTag[LockStmt] `json:"tag"`
+
+	Relations *List `json:"relations,omitempty"`
+	Mode      int   `json:"mode"`
+	Nowait    bool  `json:"nowait"`
 }
 
 func (n *LockStmt) Pos() int {
diff --git a/internal/sql/ast/locking_clause.go b/internal/sql/ast/locking_clause.go
index 6202b4ae02..00a3848f03 100644
--- a/internal/sql/ast/locking_clause.go
+++ b/internal/sql/ast/locking_clause.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type LockingClause struct {
-	LockedRels *List
-	Strength   LockClauseStrength
-	WaitPolicy LockWaitPolicy
+	Tag NodeTag[LockingClause] `json:"tag"`
+
+	LockedRels *List              `json:"locked_rels,omitempty"`
+	Strength   LockClauseStrength `json:"strength"`
+	WaitPolicy LockWaitPolicy     `json:"wait_policy"`
 }
 
 func (n *LockingClause) Pos() int {
diff --git a/internal/sql/ast/min_max_expr.go b/internal/sql/ast/min_max_expr.go
index 8f0f7ea578..56da82aed1 100644
--- a/internal/sql/ast/min_max_expr.go
+++ b/internal/sql/ast/min_max_expr.go
@@ -1,13 +1,15 @@
 package ast
 
 type MinMaxExpr struct {
-	Xpr          Node
-	Minmaxtype   Oid
-	Minmaxcollid Oid
-	Inputcollid  Oid
-	Op           MinMaxOp
-	Args         *List
-	Location     int
+	Tag NodeTag[MinMaxExpr] `json:"tag"`
+
+	Xpr          Node     `json:"xpr,omitempty"`
+	Minmaxtype   Oid      `json:"minmaxtype"`
+	Minmaxcollid Oid      `json:"minmaxcollid"`
+	Inputcollid  Oid      `json:"inputcollid"`
+	Op           MinMaxOp `json:"op"`
+	Args         *List    `json:"args,omitempty"`
+	Location     int      `json:"location"`
 }
 
 func (n *MinMaxExpr) Pos() int {
diff --git a/internal/sql/ast/multi_assign_ref.go b/internal/sql/ast/multi_assign_ref.go
index 94b783bcc1..c1a7e30fc6 100644
--- a/internal/sql/ast/multi_assign_ref.go
+++ b/internal/sql/ast/multi_assign_ref.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type MultiAssignRef struct {
-	Source   Node
-	Colno    int
-	Ncolumns int
+	Tag NodeTag[MultiAssignRef] `json:"tag"`
+
+	Source   Node `json:"source,omitempty"`
+	Colno    int  `json:"colno"`
+	Ncolumns int  `json:"ncolumns"`
 }
 
 func (n *MultiAssignRef) Pos() int {
diff --git a/internal/sql/ast/named_arg_expr.go b/internal/sql/ast/named_arg_expr.go
index a711fd2712..ec3d5a187e 100644
--- a/internal/sql/ast/named_arg_expr.go
+++ b/internal/sql/ast/named_arg_expr.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type NamedArgExpr struct {
-	Xpr       Node
-	Arg       Node
-	Name      *string
-	Argnumber int
-	Location  int
+	Tag NodeTag[NamedArgExpr] `json:"tag"`
+
+	Xpr       Node    `json:"xpr,omitempty"`
+	Arg       Node    `json:"arg,omitempty"`
+	Name      *string `json:"name,omitempty"`
+	Argnumber int     `json:"argnumber"`
+	Location  int     `json:"location"`
 }
 
 func (n *NamedArgExpr) Pos() int {
diff --git a/internal/sql/ast/next_value_expr.go b/internal/sql/ast/next_value_expr.go
index 050c090368..6832e40449 100644
--- a/internal/sql/ast/next_value_expr.go
+++ b/internal/sql/ast/next_value_expr.go
@@ -1,9 +1,11 @@
 package ast
 
 type NextValueExpr struct {
-	Xpr    Node
-	Seqid  Oid
-	TypeId Oid
+	Tag NodeTag[NextValueExpr] `json:"tag"`
+
+	Xpr    Node `json:"xpr,omitempty"`
+	Seqid  Oid  `json:"seqid"`
+	TypeId Oid  `json:"type_id"`
 }
 
 func (n *NextValueExpr) Pos() int {
diff --git a/internal/sql/ast/node_tag.go b/internal/sql/ast/node_tag.go
new file mode 100644
index 0000000000..5b3f43b90a
--- /dev/null
+++ b/internal/sql/ast/node_tag.go
@@ -0,0 +1,40 @@
+package ast
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+)
+
+// NodeTag names its containing node type in JSON.
+//
+// Node is an interface, so the JSON encoding of an AST would otherwise carry no
+// record of which node a given object is. Nodes with no fields of their own
+// (A_Star, Null, TODO) would all encode as "{}", and an empty List would be
+// indistinguishable from them. Every node struct instead declares
+//
+//	Tag NodeTag[T] `json:"tag"`
+//
+// as its first field, with T the node's own type. The field is zero-sized and
+// its zero value is valid, so constructing nodes as struct literals is
+// unaffected; encoding/json calls MarshalJSON on the field, and the type
+// parameter carries the node's identity to it at compile time.
+type NodeTag[T any] struct{}
+
+func (NodeTag[T]) MarshalJSON() ([]byte, error) {
+	return json.Marshal(reflect.TypeFor[T]().Name())
+}
+
+// UnmarshalJSON accepts only the containing node's own name, so a document
+// decoded into the wrong node type is an error rather than a silently
+// misfielded tree.
+func (*NodeTag[T]) UnmarshalJSON(data []byte) error {
+	var name string
+	if err := json.Unmarshal(data, &name); err != nil {
+		return err
+	}
+	if want := reflect.TypeFor[T]().Name(); name != want {
+		return fmt.Errorf("node tagged %q decoded into %s", name, want)
+	}
+	return nil
+}
diff --git a/internal/sql/ast/notify_stmt.go b/internal/sql/ast/notify_stmt.go
index abecb94360..1f2df47a9f 100644
--- a/internal/sql/ast/notify_stmt.go
+++ b/internal/sql/ast/notify_stmt.go
@@ -3,8 +3,10 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type NotifyStmt struct {
-	Conditionname *string
-	Payload       *string
+	Tag NodeTag[NotifyStmt] `json:"tag"`
+
+	Conditionname *string `json:"conditionname,omitempty"`
+	Payload       *string `json:"payload,omitempty"`
 }
 
 func (n *NotifyStmt) Pos() int {
diff --git a/internal/sql/ast/null.go b/internal/sql/ast/null.go
index e3606e2d7f..4fbba22f15 100644
--- a/internal/sql/ast/null.go
+++ b/internal/sql/ast/null.go
@@ -3,6 +3,7 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type Null struct {
+	Tag NodeTag[Null] `json:"tag"`
 }
 
 func (n *Null) Pos() int {
diff --git a/internal/sql/ast/null_test_expr.go b/internal/sql/ast/null_test_expr.go
index 3436bff0a5..ed0d1fddaf 100644
--- a/internal/sql/ast/null_test_expr.go
+++ b/internal/sql/ast/null_test_expr.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type NullTest struct {
-	Xpr          Node
-	Arg          Node
-	Nulltesttype NullTestType
-	Argisrow     bool
-	Location     int
+	Tag NodeTag[NullTest] `json:"tag"`
+
+	Xpr          Node         `json:"xpr,omitempty"`
+	Arg          Node         `json:"arg,omitempty"`
+	Nulltesttype NullTestType `json:"nulltesttype"`
+	Argisrow     bool         `json:"argisrow"`
+	Location     int          `json:"location"`
 }
 
 func (n *NullTest) Pos() int {
diff --git a/internal/sql/ast/object_with_args.go b/internal/sql/ast/object_with_args.go
index 5b5a1a8bd9..05b0a0ce07 100644
--- a/internal/sql/ast/object_with_args.go
+++ b/internal/sql/ast/object_with_args.go
@@ -1,9 +1,11 @@
 package ast
 
 type ObjectWithArgs struct {
-	Objname         *List
-	Objargs         *List
-	ArgsUnspecified bool
+	Tag NodeTag[ObjectWithArgs] `json:"tag"`
+
+	Objname         *List `json:"objname,omitempty"`
+	Objargs         *List `json:"objargs,omitempty"`
+	ArgsUnspecified bool  `json:"args_unspecified"`
 }
 
 func (n *ObjectWithArgs) Pos() int {
diff --git a/internal/sql/ast/on_conflict_clause.go b/internal/sql/ast/on_conflict_clause.go
index 7e04c7ff52..bbf01d6a82 100644
--- a/internal/sql/ast/on_conflict_clause.go
+++ b/internal/sql/ast/on_conflict_clause.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type OnConflictClause struct {
-	Action      OnConflictAction
-	Infer       *InferClause
-	TargetList  *List
-	WhereClause Node
-	Location    int
+	Tag NodeTag[OnConflictClause] `json:"tag"`
+
+	Action      OnConflictAction `json:"action"`
+	Infer       *InferClause     `json:"infer,omitempty"`
+	TargetList  *List            `json:"target_list,omitempty"`
+	WhereClause Node             `json:"where_clause,omitempty"`
+	Location    int              `json:"location"`
 }
 
 func (n *OnConflictClause) Pos() int {
diff --git a/internal/sql/ast/on_conflict_expr.go b/internal/sql/ast/on_conflict_expr.go
index ae9659c754..5bd559e1c8 100644
--- a/internal/sql/ast/on_conflict_expr.go
+++ b/internal/sql/ast/on_conflict_expr.go
@@ -1,14 +1,16 @@
 package ast
 
 type OnConflictExpr struct {
-	Action          OnConflictAction
-	ArbiterElems    *List
-	ArbiterWhere    Node
-	Constraint      Oid
-	OnConflictSet   *List
-	OnConflictWhere Node
-	ExclRelIndex    int
-	ExclRelTlist    *List
+	Tag NodeTag[OnConflictExpr] `json:"tag"`
+
+	Action          OnConflictAction `json:"action"`
+	ArbiterElems    *List            `json:"arbiter_elems,omitempty"`
+	ArbiterWhere    Node             `json:"arbiter_where,omitempty"`
+	Constraint      Oid              `json:"constraint"`
+	OnConflictSet   *List            `json:"on_conflict_set,omitempty"`
+	OnConflictWhere Node             `json:"on_conflict_where,omitempty"`
+	ExclRelIndex    int              `json:"excl_rel_index"`
+	ExclRelTlist    *List            `json:"excl_rel_tlist,omitempty"`
 }
 
 func (n *OnConflictExpr) Pos() int {
diff --git a/internal/sql/ast/on_duplicate_key_update.go b/internal/sql/ast/on_duplicate_key_update.go
index a11ce1ab18..bc1dbf4d13 100644
--- a/internal/sql/ast/on_duplicate_key_update.go
+++ b/internal/sql/ast/on_duplicate_key_update.go
@@ -4,9 +4,11 @@ import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 // OnDuplicateKeyUpdate represents MySQL's ON DUPLICATE KEY UPDATE clause
 type OnDuplicateKeyUpdate struct {
+	Tag NodeTag[OnDuplicateKeyUpdate] `json:"tag"`
+
 	// TargetList contains the assignments (column = value pairs)
-	TargetList *List
-	Location   int
+	TargetList *List `json:"target_list,omitempty"`
+	Location   int   `json:"location"`
 }
 
 func (n *OnDuplicateKeyUpdate) Pos() int {
diff --git a/internal/sql/ast/op_expr.go b/internal/sql/ast/op_expr.go
index 0c7c21726e..0d81af54ab 100644
--- a/internal/sql/ast/op_expr.go
+++ b/internal/sql/ast/op_expr.go
@@ -1,14 +1,16 @@
 package ast
 
 type OpExpr struct {
-	Xpr          Node
-	Opno         Oid
-	Opresulttype Oid
-	Opretset     bool
-	Opcollid     Oid
-	Inputcollid  Oid
-	Args         *List
-	Location     int
+	Tag NodeTag[OpExpr] `json:"tag"`
+
+	Xpr          Node  `json:"xpr,omitempty"`
+	Opno         Oid   `json:"opno"`
+	Opresulttype Oid   `json:"opresulttype"`
+	Opretset     bool  `json:"opretset"`
+	Opcollid     Oid   `json:"opcollid"`
+	Inputcollid  Oid   `json:"inputcollid"`
+	Args         *List `json:"args,omitempty"`
+	Location     int   `json:"location"`
 }
 
 func (n *OpExpr) Pos() int {
diff --git a/internal/sql/ast/param.go b/internal/sql/ast/param.go
index 33220800bb..d9121de50e 100644
--- a/internal/sql/ast/param.go
+++ b/internal/sql/ast/param.go
@@ -1,13 +1,15 @@
 package ast
 
 type Param struct {
-	Xpr         Node
-	Paramkind   ParamKind
-	Paramid     int
-	Paramtype   Oid
-	Paramtypmod int32
-	Paramcollid Oid
-	Location    int
+	Tag NodeTag[Param] `json:"tag"`
+
+	Xpr         Node      `json:"xpr,omitempty"`
+	Paramkind   ParamKind `json:"paramkind"`
+	Paramid     int       `json:"paramid"`
+	Paramtype   Oid       `json:"paramtype"`
+	Paramtypmod int32     `json:"paramtypmod"`
+	Paramcollid Oid       `json:"paramcollid"`
+	Location    int       `json:"location"`
 }
 
 func (n *Param) Pos() int {
diff --git a/internal/sql/ast/param_exec_data.go b/internal/sql/ast/param_exec_data.go
index 0d8c3db9bf..6f151ea20a 100644
--- a/internal/sql/ast/param_exec_data.go
+++ b/internal/sql/ast/param_exec_data.go
@@ -1,9 +1,11 @@
 package ast
 
 type ParamExecData struct {
-	ExecPlan any
-	Value    Datum
-	Isnull   bool
+	Tag NodeTag[ParamExecData] `json:"tag"`
+
+	ExecPlan any   `json:"exec_plan,omitempty"`
+	Value    Datum `json:"value"`
+	Isnull   bool  `json:"isnull"`
 }
 
 func (n *ParamExecData) Pos() int {
diff --git a/internal/sql/ast/param_extern_data.go b/internal/sql/ast/param_extern_data.go
index a5d9bfcd49..4da009ff3f 100644
--- a/internal/sql/ast/param_extern_data.go
+++ b/internal/sql/ast/param_extern_data.go
@@ -1,10 +1,12 @@
 package ast
 
 type ParamExternData struct {
-	Value  Datum
-	Isnull bool
-	Pflags uint16
-	Ptype  Oid
+	Tag NodeTag[ParamExternData] `json:"tag"`
+
+	Value  Datum  `json:"value"`
+	Isnull bool   `json:"isnull"`
+	Pflags uint16 `json:"pflags"`
+	Ptype  Oid    `json:"ptype"`
 }
 
 func (n *ParamExternData) Pos() int {
diff --git a/internal/sql/ast/param_list_info_data.go b/internal/sql/ast/param_list_info_data.go
index a3fa0796e2..30e34d0bed 100644
--- a/internal/sql/ast/param_list_info_data.go
+++ b/internal/sql/ast/param_list_info_data.go
@@ -1,10 +1,12 @@
 package ast
 
 type ParamListInfoData struct {
-	ParamFetchArg  any
-	ParserSetupArg any
-	NumParams      int
-	ParamMask      []uint32
+	Tag NodeTag[ParamListInfoData] `json:"tag"`
+
+	ParamFetchArg  any      `json:"param_fetch_arg,omitempty"`
+	ParserSetupArg any      `json:"parser_setup_arg,omitempty"`
+	NumParams      int      `json:"num_params"`
+	ParamMask      []uint32 `json:"param_mask,omitempty"`
 }
 
 func (n *ParamListInfoData) Pos() int {
diff --git a/internal/sql/ast/param_ref.go b/internal/sql/ast/param_ref.go
index 02c98f3dfb..2b7ec5c527 100644
--- a/internal/sql/ast/param_ref.go
+++ b/internal/sql/ast/param_ref.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type ParamRef struct {
-	Number   int
-	Location int
-	Dollar   bool
+	Tag NodeTag[ParamRef] `json:"tag"`
+
+	Number   int  `json:"number"`
+	Location int  `json:"location"`
+	Dollar   bool `json:"dollar"`
 }
 
 func (n *ParamRef) Pos() int {
diff --git a/internal/sql/ast/paren_expr.go b/internal/sql/ast/paren_expr.go
index 831d461f3e..79cb15b42b 100644
--- a/internal/sql/ast/paren_expr.go
+++ b/internal/sql/ast/paren_expr.go
@@ -4,8 +4,10 @@ import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 // ParenExpr represents a parenthesized expression
 type ParenExpr struct {
-	Expr     Node
-	Location int
+	Tag NodeTag[ParenExpr] `json:"tag"`
+
+	Expr     Node `json:"expr,omitempty"`
+	Location int  `json:"location"`
 }
 
 func (n *ParenExpr) Pos() int {
diff --git a/internal/sql/ast/partition_bound_spec.go b/internal/sql/ast/partition_bound_spec.go
index fb4ada70af..6f45517835 100644
--- a/internal/sql/ast/partition_bound_spec.go
+++ b/internal/sql/ast/partition_bound_spec.go
@@ -1,11 +1,13 @@
 package ast
 
 type PartitionBoundSpec struct {
-	Strategy    byte
-	Listdatums  *List
-	Lowerdatums *List
-	Upperdatums *List
-	Location    int
+	Tag NodeTag[PartitionBoundSpec] `json:"tag"`
+
+	Strategy    byte  `json:"strategy"`
+	Listdatums  *List `json:"listdatums,omitempty"`
+	Lowerdatums *List `json:"lowerdatums,omitempty"`
+	Upperdatums *List `json:"upperdatums,omitempty"`
+	Location    int   `json:"location"`
 }
 
 func (n *PartitionBoundSpec) Pos() int {
diff --git a/internal/sql/ast/partition_cmd.go b/internal/sql/ast/partition_cmd.go
index 2deb30e998..931b809172 100644
--- a/internal/sql/ast/partition_cmd.go
+++ b/internal/sql/ast/partition_cmd.go
@@ -1,8 +1,10 @@
 package ast
 
 type PartitionCmd struct {
-	Name  *RangeVar
-	Bound *PartitionBoundSpec
+	Tag NodeTag[PartitionCmd] `json:"tag"`
+
+	Name  *RangeVar           `json:"name,omitempty"`
+	Bound *PartitionBoundSpec `json:"bound,omitempty"`
 }
 
 func (n *PartitionCmd) Pos() int {
diff --git a/internal/sql/ast/partition_elem.go b/internal/sql/ast/partition_elem.go
index b4be165d36..1fe38fccb2 100644
--- a/internal/sql/ast/partition_elem.go
+++ b/internal/sql/ast/partition_elem.go
@@ -1,11 +1,13 @@
 package ast
 
 type PartitionElem struct {
-	Name      *string
-	Expr      Node
-	Collation *List
-	Opclass   *List
-	Location  int
+	Tag NodeTag[PartitionElem] `json:"tag"`
+
+	Name      *string `json:"name,omitempty"`
+	Expr      Node    `json:"expr,omitempty"`
+	Collation *List   `json:"collation,omitempty"`
+	Opclass   *List   `json:"opclass,omitempty"`
+	Location  int     `json:"location"`
 }
 
 func (n *PartitionElem) Pos() int {
diff --git a/internal/sql/ast/partition_range_datum.go b/internal/sql/ast/partition_range_datum.go
index 312437dd32..d827ced496 100644
--- a/internal/sql/ast/partition_range_datum.go
+++ b/internal/sql/ast/partition_range_datum.go
@@ -1,9 +1,11 @@
 package ast
 
 type PartitionRangeDatum struct {
-	Kind     PartitionRangeDatumKind
-	Value    Node
-	Location int
+	Tag NodeTag[PartitionRangeDatum] `json:"tag"`
+
+	Kind     PartitionRangeDatumKind `json:"kind"`
+	Value    Node                    `json:"value,omitempty"`
+	Location int                     `json:"location"`
 }
 
 func (n *PartitionRangeDatum) Pos() int {
diff --git a/internal/sql/ast/partition_spec.go b/internal/sql/ast/partition_spec.go
index 2918119e68..1d0b17400d 100644
--- a/internal/sql/ast/partition_spec.go
+++ b/internal/sql/ast/partition_spec.go
@@ -1,9 +1,11 @@
 package ast
 
 type PartitionSpec struct {
-	Strategy   *string
-	PartParams *List
-	Location   int
+	Tag NodeTag[PartitionSpec] `json:"tag"`
+
+	Strategy   *string `json:"strategy,omitempty"`
+	PartParams *List   `json:"part_params,omitempty"`
+	Location   int     `json:"location"`
 }
 
 func (n *PartitionSpec) Pos() int {
diff --git a/internal/sql/ast/prepare_stmt.go b/internal/sql/ast/prepare_stmt.go
index a088ac29b1..a31633d1c8 100644
--- a/internal/sql/ast/prepare_stmt.go
+++ b/internal/sql/ast/prepare_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type PrepareStmt struct {
-	Name     *string
-	Argtypes *List
-	Query    Node
+	Tag NodeTag[PrepareStmt] `json:"tag"`
+
+	Name     *string `json:"name,omitempty"`
+	Argtypes *List   `json:"argtypes,omitempty"`
+	Query    Node    `json:"query,omitempty"`
 }
 
 func (n *PrepareStmt) Pos() int {
diff --git a/internal/sql/ast/query.go b/internal/sql/ast/query.go
index db25dfeb5d..7ace8aa9d9 100644
--- a/internal/sql/ast/query.go
+++ b/internal/sql/ast/query.go
@@ -1,42 +1,44 @@
 package ast
 
 type Query struct {
-	CommandType      CmdType
-	QuerySource      QuerySource
-	QueryId          uint32
-	CanSetTag        bool
-	UtilityStmt      Node
-	ResultRelation   int
-	HasAggs          bool
-	HasWindowFuncs   bool
-	HasTargetSrfs    bool
-	HasSubLinks      bool
-	HasDistinctOn    bool
-	HasRecursive     bool
-	HasModifyingCte  bool
-	HasForUpdate     bool
-	HasRowSecurity   bool
-	CteList          *List
-	Rtable           *List
-	Jointree         *FromExpr
-	TargetList       *List
-	Override         OverridingKind
-	OnConflict       *OnConflictExpr
-	ReturningList    *List
-	GroupClause      *List
-	GroupingSets     *List
-	HavingQual       Node
-	WindowClause     *List
-	DistinctClause   *List
-	SortClause       *List
-	LimitOffset      Node
-	LimitCount       Node
-	RowMarks         *List
-	SetOperations    Node
-	ConstraintDeps   *List
-	WithCheckOptions *List
-	StmtLocation     int
-	StmtLen          int
+	Tag NodeTag[Query] `json:"tag"`
+
+	CommandType      CmdType         `json:"command_type"`
+	QuerySource      QuerySource     `json:"query_source"`
+	QueryId          uint32          `json:"query_id"`
+	CanSetTag        bool            `json:"can_set_tag"`
+	UtilityStmt      Node            `json:"utility_stmt,omitempty"`
+	ResultRelation   int             `json:"result_relation"`
+	HasAggs          bool            `json:"has_aggs"`
+	HasWindowFuncs   bool            `json:"has_window_funcs"`
+	HasTargetSrfs    bool            `json:"has_target_srfs"`
+	HasSubLinks      bool            `json:"has_sub_links"`
+	HasDistinctOn    bool            `json:"has_distinct_on"`
+	HasRecursive     bool            `json:"has_recursive"`
+	HasModifyingCte  bool            `json:"has_modifying_cte"`
+	HasForUpdate     bool            `json:"has_for_update"`
+	HasRowSecurity   bool            `json:"has_row_security"`
+	CteList          *List           `json:"cte_list,omitempty"`
+	Rtable           *List           `json:"rtable,omitempty"`
+	Jointree         *FromExpr       `json:"jointree,omitempty"`
+	TargetList       *List           `json:"target_list,omitempty"`
+	Override         OverridingKind  `json:"override"`
+	OnConflict       *OnConflictExpr `json:"on_conflict,omitempty"`
+	ReturningList    *List           `json:"returning_list,omitempty"`
+	GroupClause      *List           `json:"group_clause,omitempty"`
+	GroupingSets     *List           `json:"grouping_sets,omitempty"`
+	HavingQual       Node            `json:"having_qual,omitempty"`
+	WindowClause     *List           `json:"window_clause,omitempty"`
+	DistinctClause   *List           `json:"distinct_clause,omitempty"`
+	SortClause       *List           `json:"sort_clause,omitempty"`
+	LimitOffset      Node            `json:"limit_offset,omitempty"`
+	LimitCount       Node            `json:"limit_count,omitempty"`
+	RowMarks         *List           `json:"row_marks,omitempty"`
+	SetOperations    Node            `json:"set_operations,omitempty"`
+	ConstraintDeps   *List           `json:"constraint_deps,omitempty"`
+	WithCheckOptions *List           `json:"with_check_options,omitempty"`
+	StmtLocation     int             `json:"stmt_location"`
+	StmtLen          int             `json:"stmt_len"`
 }
 
 func (n *Query) Pos() int {
diff --git a/internal/sql/ast/range_function.go b/internal/sql/ast/range_function.go
index dca63595d8..3d1b6d0c30 100644
--- a/internal/sql/ast/range_function.go
+++ b/internal/sql/ast/range_function.go
@@ -3,12 +3,14 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type RangeFunction struct {
-	Lateral    bool
-	Ordinality bool
-	IsRowsfrom bool
-	Functions  *List
-	Alias      *Alias
-	Coldeflist *List
+	Tag NodeTag[RangeFunction] `json:"tag"`
+
+	Lateral    bool   `json:"lateral"`
+	Ordinality bool   `json:"ordinality"`
+	IsRowsfrom bool   `json:"is_rowsfrom"`
+	Functions  *List  `json:"functions,omitempty"`
+	Alias      *Alias `json:"alias,omitempty"`
+	Coldeflist *List  `json:"coldeflist,omitempty"`
 }
 
 func (n *RangeFunction) Pos() int {
diff --git a/internal/sql/ast/range_subselect.go b/internal/sql/ast/range_subselect.go
index 51a8825e2b..8f2efe9b1e 100644
--- a/internal/sql/ast/range_subselect.go
+++ b/internal/sql/ast/range_subselect.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type RangeSubselect struct {
-	Lateral  bool
-	Subquery Node
-	Alias    *Alias
+	Tag NodeTag[RangeSubselect] `json:"tag"`
+
+	Lateral  bool   `json:"lateral"`
+	Subquery Node   `json:"subquery,omitempty"`
+	Alias    *Alias `json:"alias,omitempty"`
 }
 
 func (n *RangeSubselect) Pos() int {
diff --git a/internal/sql/ast/range_table_func.go b/internal/sql/ast/range_table_func.go
index e53992edab..7758339c96 100644
--- a/internal/sql/ast/range_table_func.go
+++ b/internal/sql/ast/range_table_func.go
@@ -1,13 +1,15 @@
 package ast
 
 type RangeTableFunc struct {
-	Lateral    bool
-	Docexpr    Node
-	Rowexpr    Node
-	Namespaces *List
-	Columns    *List
-	Alias      *Alias
-	Location   int
+	Tag NodeTag[RangeTableFunc] `json:"tag"`
+
+	Lateral    bool   `json:"lateral"`
+	Docexpr    Node   `json:"docexpr,omitempty"`
+	Rowexpr    Node   `json:"rowexpr,omitempty"`
+	Namespaces *List  `json:"namespaces,omitempty"`
+	Columns    *List  `json:"columns,omitempty"`
+	Alias      *Alias `json:"alias,omitempty"`
+	Location   int    `json:"location"`
 }
 
 func (n *RangeTableFunc) Pos() int {
diff --git a/internal/sql/ast/range_table_func_col.go b/internal/sql/ast/range_table_func_col.go
index 2c06db1c08..d3fc620f3b 100644
--- a/internal/sql/ast/range_table_func_col.go
+++ b/internal/sql/ast/range_table_func_col.go
@@ -1,13 +1,15 @@
 package ast
 
 type RangeTableFuncCol struct {
-	Colname       *string
-	TypeName      *TypeName
-	ForOrdinality bool
-	IsNotNull     bool
-	Colexpr       Node
-	Coldefexpr    Node
-	Location      int
+	Tag NodeTag[RangeTableFuncCol] `json:"tag"`
+
+	Colname       *string   `json:"colname,omitempty"`
+	TypeName      *TypeName `json:"type_name,omitempty"`
+	ForOrdinality bool      `json:"for_ordinality"`
+	IsNotNull     bool      `json:"is_not_null"`
+	Colexpr       Node      `json:"colexpr,omitempty"`
+	Coldefexpr    Node      `json:"coldefexpr,omitempty"`
+	Location      int       `json:"location"`
 }
 
 func (n *RangeTableFuncCol) Pos() int {
diff --git a/internal/sql/ast/range_table_sample.go b/internal/sql/ast/range_table_sample.go
index c5fa2a2880..cf4c41f5b8 100644
--- a/internal/sql/ast/range_table_sample.go
+++ b/internal/sql/ast/range_table_sample.go
@@ -1,11 +1,13 @@
 package ast
 
 type RangeTableSample struct {
-	Relation   Node
-	Method     *List
-	Args       *List
-	Repeatable Node
-	Location   int
+	Tag NodeTag[RangeTableSample] `json:"tag"`
+
+	Relation   Node  `json:"relation,omitempty"`
+	Method     *List `json:"method,omitempty"`
+	Args       *List `json:"args,omitempty"`
+	Repeatable Node  `json:"repeatable,omitempty"`
+	Location   int   `json:"location"`
 }
 
 func (n *RangeTableSample) Pos() int {
diff --git a/internal/sql/ast/range_tbl_entry.go b/internal/sql/ast/range_tbl_entry.go
index be40e619b4..e3dbf2b39f 100644
--- a/internal/sql/ast/range_tbl_entry.go
+++ b/internal/sql/ast/range_tbl_entry.go
@@ -1,37 +1,39 @@
 package ast
 
 type RangeTblEntry struct {
-	Rtekind         RTEKind
-	Relid           Oid
-	Relkind         byte
-	Tablesample     *TableSampleClause
-	Subquery        *Query
-	SecurityBarrier bool
-	Jointype        JoinType
-	Joinaliasvars   *List
-	Functions       *List
-	Funcordinality  bool
-	Tablefunc       *TableFunc
-	ValuesLists     *List
-	Ctename         *string
-	Ctelevelsup     Index
-	SelfReference   bool
-	Coltypes        *List
-	Coltypmods      *List
-	Colcollations   *List
-	Enrname         *string
-	Enrtuples       float64
-	Alias           *Alias
-	Eref            *Alias
-	Lateral         bool
-	Inh             bool
-	InFromCl        bool
-	RequiredPerms   AclMode
-	CheckAsUser     Oid
-	SelectedCols    []uint32
-	InsertedCols    []uint32
-	UpdatedCols     []uint32
-	SecurityQuals   *List
+	Tag NodeTag[RangeTblEntry] `json:"tag"`
+
+	Rtekind         RTEKind            `json:"rtekind"`
+	Relid           Oid                `json:"relid"`
+	Relkind         byte               `json:"relkind"`
+	Tablesample     *TableSampleClause `json:"tablesample,omitempty"`
+	Subquery        *Query             `json:"subquery,omitempty"`
+	SecurityBarrier bool               `json:"security_barrier"`
+	Jointype        JoinType           `json:"jointype"`
+	Joinaliasvars   *List              `json:"joinaliasvars,omitempty"`
+	Functions       *List              `json:"functions,omitempty"`
+	Funcordinality  bool               `json:"funcordinality"`
+	Tablefunc       *TableFunc         `json:"tablefunc,omitempty"`
+	ValuesLists     *List              `json:"values_lists,omitempty"`
+	Ctename         *string            `json:"ctename,omitempty"`
+	Ctelevelsup     Index              `json:"ctelevelsup"`
+	SelfReference   bool               `json:"self_reference"`
+	Coltypes        *List              `json:"coltypes,omitempty"`
+	Coltypmods      *List              `json:"coltypmods,omitempty"`
+	Colcollations   *List              `json:"colcollations,omitempty"`
+	Enrname         *string            `json:"enrname,omitempty"`
+	Enrtuples       float64            `json:"enrtuples"`
+	Alias           *Alias             `json:"alias,omitempty"`
+	Eref            *Alias             `json:"eref,omitempty"`
+	Lateral         bool               `json:"lateral"`
+	Inh             bool               `json:"inh"`
+	InFromCl        bool               `json:"in_from_cl"`
+	RequiredPerms   AclMode            `json:"required_perms"`
+	CheckAsUser     Oid                `json:"check_as_user"`
+	SelectedCols    []uint32           `json:"selected_cols,omitempty"`
+	InsertedCols    []uint32           `json:"inserted_cols,omitempty"`
+	UpdatedCols     []uint32           `json:"updated_cols,omitempty"`
+	SecurityQuals   *List              `json:"security_quals,omitempty"`
 }
 
 func (n *RangeTblEntry) Pos() int {
diff --git a/internal/sql/ast/range_tbl_function.go b/internal/sql/ast/range_tbl_function.go
index ee0e609f74..c4f54e1d55 100644
--- a/internal/sql/ast/range_tbl_function.go
+++ b/internal/sql/ast/range_tbl_function.go
@@ -1,13 +1,15 @@
 package ast
 
 type RangeTblFunction struct {
-	Funcexpr          Node
-	Funccolcount      int
-	Funccolnames      *List
-	Funccoltypes      *List
-	Funccoltypmods    *List
-	Funccolcollations *List
-	Funcparams        []uint32
+	Tag NodeTag[RangeTblFunction] `json:"tag"`
+
+	Funcexpr          Node     `json:"funcexpr,omitempty"`
+	Funccolcount      int      `json:"funccolcount"`
+	Funccolnames      *List    `json:"funccolnames,omitempty"`
+	Funccoltypes      *List    `json:"funccoltypes,omitempty"`
+	Funccoltypmods    *List    `json:"funccoltypmods,omitempty"`
+	Funccolcollations *List    `json:"funccolcollations,omitempty"`
+	Funcparams        []uint32 `json:"funcparams,omitempty"`
 }
 
 func (n *RangeTblFunction) Pos() int {
diff --git a/internal/sql/ast/range_tbl_ref.go b/internal/sql/ast/range_tbl_ref.go
index de537568de..e3e1cc2a22 100644
--- a/internal/sql/ast/range_tbl_ref.go
+++ b/internal/sql/ast/range_tbl_ref.go
@@ -1,7 +1,9 @@
 package ast
 
 type RangeTblRef struct {
-	Rtindex int
+	Tag NodeTag[RangeTblRef] `json:"tag"`
+
+	Rtindex int `json:"rtindex"`
 }
 
 func (n *RangeTblRef) Pos() int {
diff --git a/internal/sql/ast/range_var.go b/internal/sql/ast/range_var.go
index 250b2b3bbf..ce70c97114 100644
--- a/internal/sql/ast/range_var.go
+++ b/internal/sql/ast/range_var.go
@@ -3,13 +3,15 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type RangeVar struct {
-	Catalogname    *string
-	Schemaname     *string
-	Relname        *string
-	Inh            bool
-	Relpersistence byte
-	Alias          *Alias
-	Location       int
+	Tag NodeTag[RangeVar] `json:"tag"`
+
+	Catalogname    *string `json:"catalogname,omitempty"`
+	Schemaname     *string `json:"schemaname,omitempty"`
+	Relname        *string `json:"relname,omitempty"`
+	Inh            bool    `json:"inh"`
+	Relpersistence byte    `json:"relpersistence"`
+	Alias          *Alias  `json:"alias,omitempty"`
+	Location       int     `json:"location"`
 }
 
 func (n *RangeVar) Pos() int {
diff --git a/internal/sql/ast/raw_stmt.go b/internal/sql/ast/raw_stmt.go
index 619b844244..73e50d508e 100644
--- a/internal/sql/ast/raw_stmt.go
+++ b/internal/sql/ast/raw_stmt.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type RawStmt struct {
-	Stmt         Node
-	StmtLocation int
-	StmtLen      int
+	Tag NodeTag[RawStmt] `json:"tag"`
+
+	Stmt         Node `json:"stmt,omitempty"`
+	StmtLocation int  `json:"stmt_location"`
+	StmtLen      int  `json:"stmt_len"`
 }
 
 func (n *RawStmt) Pos() int {
diff --git a/internal/sql/ast/reassign_owned_stmt.go b/internal/sql/ast/reassign_owned_stmt.go
index 9162131f46..d062e7826c 100644
--- a/internal/sql/ast/reassign_owned_stmt.go
+++ b/internal/sql/ast/reassign_owned_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type ReassignOwnedStmt struct {
-	Roles   *List
-	Newrole *RoleSpec
+	Tag NodeTag[ReassignOwnedStmt] `json:"tag"`
+
+	Roles   *List     `json:"roles,omitempty"`
+	Newrole *RoleSpec `json:"newrole,omitempty"`
 }
 
 func (n *ReassignOwnedStmt) Pos() int {
diff --git a/internal/sql/ast/refresh_mat_view_stmt.go b/internal/sql/ast/refresh_mat_view_stmt.go
index f627e7bf21..d8c76e55f7 100644
--- a/internal/sql/ast/refresh_mat_view_stmt.go
+++ b/internal/sql/ast/refresh_mat_view_stmt.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type RefreshMatViewStmt struct {
-	Concurrent bool
-	SkipData   bool
-	Relation   *RangeVar
+	Tag NodeTag[RefreshMatViewStmt] `json:"tag"`
+
+	Concurrent bool      `json:"concurrent"`
+	SkipData   bool      `json:"skip_data"`
+	Relation   *RangeVar `json:"relation,omitempty"`
 }
 
 func (n *RefreshMatViewStmt) Pos() int {
diff --git a/internal/sql/ast/reindex_stmt.go b/internal/sql/ast/reindex_stmt.go
index 9d33d490fe..7261134655 100644
--- a/internal/sql/ast/reindex_stmt.go
+++ b/internal/sql/ast/reindex_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type ReindexStmt struct {
-	Kind     ReindexObjectType
-	Relation *RangeVar
-	Name     *string
-	Options  int
+	Tag NodeTag[ReindexStmt] `json:"tag"`
+
+	Kind     ReindexObjectType `json:"kind"`
+	Relation *RangeVar         `json:"relation,omitempty"`
+	Name     *string           `json:"name,omitempty"`
+	Options  int               `json:"options"`
 }
 
 func (n *ReindexStmt) Pos() int {
diff --git a/internal/sql/ast/relabel_type.go b/internal/sql/ast/relabel_type.go
index e30e93184e..efaf74250c 100644
--- a/internal/sql/ast/relabel_type.go
+++ b/internal/sql/ast/relabel_type.go
@@ -1,13 +1,15 @@
 package ast
 
 type RelabelType struct {
-	Xpr           Node
-	Arg           Node
-	Resulttype    Oid
-	Resulttypmod  int32
-	Resultcollid  Oid
-	Relabelformat CoercionForm
-	Location      int
+	Tag NodeTag[RelabelType] `json:"tag"`
+
+	Xpr           Node         `json:"xpr,omitempty"`
+	Arg           Node         `json:"arg,omitempty"`
+	Resulttype    Oid          `json:"resulttype"`
+	Resulttypmod  int32        `json:"resulttypmod"`
+	Resultcollid  Oid          `json:"resultcollid"`
+	Relabelformat CoercionForm `json:"relabelformat"`
+	Location      int          `json:"location"`
 }
 
 func (n *RelabelType) Pos() int {
diff --git a/internal/sql/ast/rename_column_stmt.go b/internal/sql/ast/rename_column_stmt.go
index 498b89d6ef..e677ce4661 100644
--- a/internal/sql/ast/rename_column_stmt.go
+++ b/internal/sql/ast/rename_column_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type RenameColumnStmt struct {
-	Table     *TableName
-	Col       *ColumnRef
-	NewName   *string
-	MissingOk bool
+	Tag NodeTag[RenameColumnStmt] `json:"tag"`
+
+	Table     *TableName `json:"table,omitempty"`
+	Col       *ColumnRef `json:"col,omitempty"`
+	NewName   *string    `json:"new_name,omitempty"`
+	MissingOk bool       `json:"missing_ok"`
 }
 
 func (n *RenameColumnStmt) Pos() int {
diff --git a/internal/sql/ast/rename_stmt.go b/internal/sql/ast/rename_stmt.go
index cb9c176324..47865132c8 100644
--- a/internal/sql/ast/rename_stmt.go
+++ b/internal/sql/ast/rename_stmt.go
@@ -1,14 +1,16 @@
 package ast
 
 type RenameStmt struct {
-	RenameType   ObjectType
-	RelationType ObjectType
-	Relation     *RangeVar
-	Object       Node
-	Subname      *string
-	Newname      *string
-	Behavior     DropBehavior
-	MissingOk    bool
+	Tag NodeTag[RenameStmt] `json:"tag"`
+
+	RenameType   ObjectType   `json:"rename_type"`
+	RelationType ObjectType   `json:"relation_type"`
+	Relation     *RangeVar    `json:"relation,omitempty"`
+	Object       Node         `json:"object,omitempty"`
+	Subname      *string      `json:"subname,omitempty"`
+	Newname      *string      `json:"newname,omitempty"`
+	Behavior     DropBehavior `json:"behavior"`
+	MissingOk    bool         `json:"missing_ok"`
 }
 
 func (n *RenameStmt) Pos() int {
diff --git a/internal/sql/ast/rename_table_stmt.go b/internal/sql/ast/rename_table_stmt.go
index b879ddb0b7..a8473e0310 100644
--- a/internal/sql/ast/rename_table_stmt.go
+++ b/internal/sql/ast/rename_table_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type RenameTableStmt struct {
-	Table     *TableName
-	NewName   *string
-	MissingOk bool
+	Tag NodeTag[RenameTableStmt] `json:"tag"`
+
+	Table     *TableName `json:"table,omitempty"`
+	NewName   *string    `json:"new_name,omitempty"`
+	MissingOk bool       `json:"missing_ok"`
 }
 
 func (n *RenameTableStmt) Pos() int {
diff --git a/internal/sql/ast/rename_type_stmt.go b/internal/sql/ast/rename_type_stmt.go
index 67472d02f2..fced204dc8 100644
--- a/internal/sql/ast/rename_type_stmt.go
+++ b/internal/sql/ast/rename_type_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type RenameTypeStmt struct {
-	Type    *TypeName
-	NewName *string
+	Tag NodeTag[RenameTypeStmt] `json:"tag"`
+
+	Type    *TypeName `json:"type,omitempty"`
+	NewName *string   `json:"new_name,omitempty"`
 }
 
 func (n *RenameTypeStmt) Pos() int {
diff --git a/internal/sql/ast/replica_identity_stmt.go b/internal/sql/ast/replica_identity_stmt.go
index 2d4291597b..abe08e05e4 100644
--- a/internal/sql/ast/replica_identity_stmt.go
+++ b/internal/sql/ast/replica_identity_stmt.go
@@ -1,8 +1,10 @@
 package ast
 
 type ReplicaIdentityStmt struct {
-	IdentityType byte
-	Name         *string
+	Tag NodeTag[ReplicaIdentityStmt] `json:"tag"`
+
+	IdentityType byte    `json:"identity_type"`
+	Name         *string `json:"name,omitempty"`
 }
 
 func (n *ReplicaIdentityStmt) Pos() int {
diff --git a/internal/sql/ast/res_target.go b/internal/sql/ast/res_target.go
index dc34879942..58a7e1dac5 100644
--- a/internal/sql/ast/res_target.go
+++ b/internal/sql/ast/res_target.go
@@ -3,10 +3,12 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type ResTarget struct {
-	Name        *string
-	Indirection *List
-	Val         Node
-	Location    int
+	Tag NodeTag[ResTarget] `json:"tag"`
+
+	Name        *string `json:"name,omitempty"`
+	Indirection *List   `json:"indirection,omitempty"`
+	Val         Node    `json:"val,omitempty"`
+	Location    int     `json:"location"`
 }
 
 func (n *ResTarget) Pos() int {
diff --git a/internal/sql/ast/role_spec.go b/internal/sql/ast/role_spec.go
index fba4cecf7d..154ddf3ce4 100644
--- a/internal/sql/ast/role_spec.go
+++ b/internal/sql/ast/role_spec.go
@@ -1,9 +1,11 @@
 package ast
 
 type RoleSpec struct {
-	Roletype RoleSpecType
-	Rolename *string
-	Location int
+	Tag NodeTag[RoleSpec] `json:"tag"`
+
+	Roletype RoleSpecType `json:"roletype"`
+	Rolename *string      `json:"rolename,omitempty"`
+	Location int          `json:"location"`
 }
 
 func (n *RoleSpec) Pos() int {
diff --git a/internal/sql/ast/row_compare_expr.go b/internal/sql/ast/row_compare_expr.go
index 884cc3420d..bbab320eda 100644
--- a/internal/sql/ast/row_compare_expr.go
+++ b/internal/sql/ast/row_compare_expr.go
@@ -1,13 +1,15 @@
 package ast
 
 type RowCompareExpr struct {
-	Xpr          Node
-	Rctype       RowCompareType
-	Opnos        *List
-	Opfamilies   *List
-	Inputcollids *List
-	Largs        *List
-	Rargs        *List
+	Tag NodeTag[RowCompareExpr] `json:"tag"`
+
+	Xpr          Node           `json:"xpr,omitempty"`
+	Rctype       RowCompareType `json:"rctype"`
+	Opnos        *List          `json:"opnos,omitempty"`
+	Opfamilies   *List          `json:"opfamilies,omitempty"`
+	Inputcollids *List          `json:"inputcollids,omitempty"`
+	Largs        *List          `json:"largs,omitempty"`
+	Rargs        *List          `json:"rargs,omitempty"`
 }
 
 func (n *RowCompareExpr) Pos() int {
diff --git a/internal/sql/ast/row_expr.go b/internal/sql/ast/row_expr.go
index 0f8578355a..d898086da6 100644
--- a/internal/sql/ast/row_expr.go
+++ b/internal/sql/ast/row_expr.go
@@ -3,12 +3,14 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type RowExpr struct {
-	Xpr       Node
-	Args      *List
-	RowTypeid Oid
-	RowFormat CoercionForm
-	Colnames  *List
-	Location  int
+	Tag NodeTag[RowExpr] `json:"tag"`
+
+	Xpr       Node         `json:"xpr,omitempty"`
+	Args      *List        `json:"args,omitempty"`
+	RowTypeid Oid          `json:"row_typeid"`
+	RowFormat CoercionForm `json:"row_format"`
+	Colnames  *List        `json:"colnames,omitempty"`
+	Location  int          `json:"location"`
 }
 
 func (n *RowExpr) Pos() int {
diff --git a/internal/sql/ast/row_mark_clause.go b/internal/sql/ast/row_mark_clause.go
index 5f2f8fa2f2..121174e6ba 100644
--- a/internal/sql/ast/row_mark_clause.go
+++ b/internal/sql/ast/row_mark_clause.go
@@ -1,10 +1,12 @@
 package ast
 
 type RowMarkClause struct {
-	Rti        Index
-	Strength   LockClauseStrength
-	WaitPolicy LockWaitPolicy
-	PushedDown bool
+	Tag NodeTag[RowMarkClause] `json:"tag"`
+
+	Rti        Index              `json:"rti"`
+	Strength   LockClauseStrength `json:"strength"`
+	WaitPolicy LockWaitPolicy     `json:"wait_policy"`
+	PushedDown bool               `json:"pushed_down"`
 }
 
 func (n *RowMarkClause) Pos() int {
diff --git a/internal/sql/ast/rule_stmt.go b/internal/sql/ast/rule_stmt.go
index 5ed05a8c5f..7821866d58 100644
--- a/internal/sql/ast/rule_stmt.go
+++ b/internal/sql/ast/rule_stmt.go
@@ -1,13 +1,15 @@
 package ast
 
 type RuleStmt struct {
-	Relation    *RangeVar
-	Rulename    *string
-	WhereClause Node
-	Event       CmdType
-	Instead     bool
-	Actions     *List
-	Replace     bool
+	Tag NodeTag[RuleStmt] `json:"tag"`
+
+	Relation    *RangeVar `json:"relation,omitempty"`
+	Rulename    *string   `json:"rulename,omitempty"`
+	WhereClause Node      `json:"where_clause,omitempty"`
+	Event       CmdType   `json:"event"`
+	Instead     bool      `json:"instead"`
+	Actions     *List     `json:"actions,omitempty"`
+	Replace     bool      `json:"replace"`
 }
 
 func (n *RuleStmt) Pos() int {
diff --git a/internal/sql/ast/scalar_array_op_expr.go b/internal/sql/ast/scalar_array_op_expr.go
index b4f36548b3..a427fd0e67 100644
--- a/internal/sql/ast/scalar_array_op_expr.go
+++ b/internal/sql/ast/scalar_array_op_expr.go
@@ -3,12 +3,14 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type ScalarArrayOpExpr struct {
-	Xpr         Node
-	Opno        Oid
-	UseOr       bool
-	Inputcollid Oid
-	Args        *List
-	Location    int
+	Tag NodeTag[ScalarArrayOpExpr] `json:"tag"`
+
+	Xpr         Node  `json:"xpr,omitempty"`
+	Opno        Oid   `json:"opno"`
+	UseOr       bool  `json:"use_or"`
+	Inputcollid Oid   `json:"inputcollid"`
+	Args        *List `json:"args,omitempty"`
+	Location    int   `json:"location"`
 }
 
 func (n *ScalarArrayOpExpr) Pos() int {
diff --git a/internal/sql/ast/sec_label_stmt.go b/internal/sql/ast/sec_label_stmt.go
index 608edb733f..3a00bee0c4 100644
--- a/internal/sql/ast/sec_label_stmt.go
+++ b/internal/sql/ast/sec_label_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type SecLabelStmt struct {
-	Objtype  ObjectType
-	Object   Node
-	Provider *string
-	Label    *string
+	Tag NodeTag[SecLabelStmt] `json:"tag"`
+
+	Objtype  ObjectType `json:"objtype"`
+	Object   Node       `json:"object,omitempty"`
+	Provider *string    `json:"provider,omitempty"`
+	Label    *string    `json:"label,omitempty"`
 }
 
 func (n *SecLabelStmt) Pos() int {
diff --git a/internal/sql/ast/select_stmt.go b/internal/sql/ast/select_stmt.go
index 226c110734..ad9e10f9a1 100644
--- a/internal/sql/ast/select_stmt.go
+++ b/internal/sql/ast/select_stmt.go
@@ -5,24 +5,26 @@ import (
 )
 
 type SelectStmt struct {
-	DistinctClause *List
-	IntoClause     *IntoClause
-	TargetList     *List
-	FromClause     *List
-	WhereClause    Node
-	GroupClause    *List
-	HavingClause   Node
-	WindowClause   *List
-	ValuesLists    *List
-	SortClause     *List
-	LimitOffset    Node
-	LimitCount     Node
-	LockingClause  *List
-	WithClause     *WithClause
-	Op             SetOperation
-	All            bool
-	Larg           *SelectStmt
-	Rarg           *SelectStmt
+	Tag NodeTag[SelectStmt] `json:"tag"`
+
+	DistinctClause *List        `json:"distinct_clause,omitempty"`
+	IntoClause     *IntoClause  `json:"into_clause,omitempty"`
+	TargetList     *List        `json:"target_list,omitempty"`
+	FromClause     *List        `json:"from_clause,omitempty"`
+	WhereClause    Node         `json:"where_clause,omitempty"`
+	GroupClause    *List        `json:"group_clause,omitempty"`
+	HavingClause   Node         `json:"having_clause,omitempty"`
+	WindowClause   *List        `json:"window_clause,omitempty"`
+	ValuesLists    *List        `json:"values_lists,omitempty"`
+	SortClause     *List        `json:"sort_clause,omitempty"`
+	LimitOffset    Node         `json:"limit_offset,omitempty"`
+	LimitCount     Node         `json:"limit_count,omitempty"`
+	LockingClause  *List        `json:"locking_clause,omitempty"`
+	WithClause     *WithClause  `json:"with_clause,omitempty"`
+	Op             SetOperation `json:"op"`
+	All            bool         `json:"all"`
+	Larg           *SelectStmt  `json:"larg,omitempty"`
+	Rarg           *SelectStmt  `json:"rarg,omitempty"`
 }
 
 func (n *SelectStmt) Pos() int {
diff --git a/internal/sql/ast/set_operation_stmt.go b/internal/sql/ast/set_operation_stmt.go
index 9ab1950d1b..975460facb 100644
--- a/internal/sql/ast/set_operation_stmt.go
+++ b/internal/sql/ast/set_operation_stmt.go
@@ -1,14 +1,16 @@
 package ast
 
 type SetOperationStmt struct {
-	Op            SetOperation
-	All           bool
-	Larg          Node
-	Rarg          Node
-	ColTypes      *List
-	ColTypmods    *List
-	ColCollations *List
-	GroupClauses  *List
+	Tag NodeTag[SetOperationStmt] `json:"tag"`
+
+	Op            SetOperation `json:"op"`
+	All           bool         `json:"all"`
+	Larg          Node         `json:"larg,omitempty"`
+	Rarg          Node         `json:"rarg,omitempty"`
+	ColTypes      *List        `json:"col_types,omitempty"`
+	ColTypmods    *List        `json:"col_typmods,omitempty"`
+	ColCollations *List        `json:"col_collations,omitempty"`
+	GroupClauses  *List        `json:"group_clauses,omitempty"`
 }
 
 func (n *SetOperationStmt) Pos() int {
diff --git a/internal/sql/ast/set_to_default.go b/internal/sql/ast/set_to_default.go
index c127d3bc77..6ae1d066c4 100644
--- a/internal/sql/ast/set_to_default.go
+++ b/internal/sql/ast/set_to_default.go
@@ -1,11 +1,13 @@
 package ast
 
 type SetToDefault struct {
-	Xpr       Node
-	TypeId    Oid
-	TypeMod   int32
-	Collation Oid
-	Location  int
+	Tag NodeTag[SetToDefault] `json:"tag"`
+
+	Xpr       Node  `json:"xpr,omitempty"`
+	TypeId    Oid   `json:"type_id"`
+	TypeMod   int32 `json:"type_mod"`
+	Collation Oid   `json:"collation"`
+	Location  int   `json:"location"`
 }
 
 func (n *SetToDefault) Pos() int {
diff --git a/internal/sql/ast/sort_by.go b/internal/sql/ast/sort_by.go
index b8634b7d6d..f1e241cc54 100644
--- a/internal/sql/ast/sort_by.go
+++ b/internal/sql/ast/sort_by.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type SortBy struct {
-	Node        Node
-	SortbyDir   SortByDir
-	SortbyNulls SortByNulls
-	UseOp       *List
-	Location    int
+	Tag NodeTag[SortBy] `json:"tag"`
+
+	Node        Node        `json:"node,omitempty"`
+	SortbyDir   SortByDir   `json:"sortby_dir"`
+	SortbyNulls SortByNulls `json:"sortby_nulls"`
+	UseOp       *List       `json:"use_op,omitempty"`
+	Location    int         `json:"location"`
 }
 
 func (n *SortBy) Pos() int {
diff --git a/internal/sql/ast/sort_group_clause.go b/internal/sql/ast/sort_group_clause.go
index 775035d799..e28cc89a8b 100644
--- a/internal/sql/ast/sort_group_clause.go
+++ b/internal/sql/ast/sort_group_clause.go
@@ -1,11 +1,13 @@
 package ast
 
 type SortGroupClause struct {
-	TleSortGroupRef Index
-	Eqop            Oid
-	Sortop          Oid
-	NullsFirst      bool
-	Hashable        bool
+	Tag NodeTag[SortGroupClause] `json:"tag"`
+
+	TleSortGroupRef Index `json:"tle_sort_group_ref"`
+	Eqop            Oid   `json:"eqop"`
+	Sortop          Oid   `json:"sortop"`
+	NullsFirst      bool  `json:"nulls_first"`
+	Hashable        bool  `json:"hashable"`
 }
 
 func (n *SortGroupClause) Pos() int {
diff --git a/internal/sql/ast/sql_value_function.go b/internal/sql/ast/sql_value_function.go
index 31bd008245..4c9fd2b670 100644
--- a/internal/sql/ast/sql_value_function.go
+++ b/internal/sql/ast/sql_value_function.go
@@ -3,11 +3,13 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type SQLValueFunction struct {
-	Xpr      Node
-	Op       SQLValueFunctionOp
-	Type     Oid
-	Typmod   int32
-	Location int
+	Tag NodeTag[SQLValueFunction] `json:"tag"`
+
+	Xpr      Node               `json:"xpr,omitempty"`
+	Op       SQLValueFunctionOp `json:"op"`
+	Type     Oid                `json:"type"`
+	Typmod   int32              `json:"typmod"`
+	Location int                `json:"location"`
 }
 
 func (n *SQLValueFunction) Pos() int {
diff --git a/internal/sql/ast/statement.go b/internal/sql/ast/statement.go
index 4d01d949ca..dff54d6fb8 100644
--- a/internal/sql/ast/statement.go
+++ b/internal/sql/ast/statement.go
@@ -1,7 +1,9 @@
 package ast
 
 type Statement struct {
-	Raw *RawStmt
+	Tag NodeTag[Statement] `json:"tag"`
+
+	Raw *RawStmt `json:"raw,omitempty"`
 }
 
 func (n *Statement) Pos() int {
diff --git a/internal/sql/ast/string.go b/internal/sql/ast/string.go
index d167ef4575..b2ebe3b211 100644
--- a/internal/sql/ast/string.go
+++ b/internal/sql/ast/string.go
@@ -3,7 +3,9 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type String struct {
-	Str string
+	Tag NodeTag[String] `json:"tag"`
+
+	Str string `json:"str"`
 }
 
 func (n *String) Pos() int {
diff --git a/internal/sql/ast/sub_link.go b/internal/sql/ast/sub_link.go
index bfd3ded206..184f36c96f 100644
--- a/internal/sql/ast/sub_link.go
+++ b/internal/sql/ast/sub_link.go
@@ -16,13 +16,15 @@ const (
 )
 
 type SubLink struct {
-	Xpr         Node
-	SubLinkType SubLinkType
-	SubLinkId   int
-	Testexpr    Node
-	OperName    *List
-	Subselect   Node
-	Location    int
+	Tag NodeTag[SubLink] `json:"tag"`
+
+	Xpr         Node        `json:"xpr,omitempty"`
+	SubLinkType SubLinkType `json:"sub_link_type"`
+	SubLinkId   int         `json:"sub_link_id"`
+	Testexpr    Node        `json:"testexpr,omitempty"`
+	OperName    *List       `json:"oper_name,omitempty"`
+	Subselect   Node        `json:"subselect,omitempty"`
+	Location    int         `json:"location"`
 }
 
 func (n *SubLink) Pos() int {
diff --git a/internal/sql/ast/sub_plan.go b/internal/sql/ast/sub_plan.go
index 2443e86c98..50908c7134 100644
--- a/internal/sql/ast/sub_plan.go
+++ b/internal/sql/ast/sub_plan.go
@@ -1,23 +1,25 @@
 package ast
 
 type SubPlan struct {
-	Xpr               Node
-	SubLinkType       SubLinkType
-	Testexpr          Node
-	ParamIds          *List
-	PlanId            int
-	PlanName          *string
-	FirstColType      Oid
-	FirstColTypmod    int32
-	FirstColCollation Oid
-	UseHashTable      bool
-	UnknownEqFalse    bool
-	ParallelSafe      bool
-	SetParam          *List
-	ParParam          *List
-	Args              *List
-	StartupCost       Cost
-	PerCallCost       Cost
+	Tag NodeTag[SubPlan] `json:"tag"`
+
+	Xpr               Node        `json:"xpr,omitempty"`
+	SubLinkType       SubLinkType `json:"sub_link_type"`
+	Testexpr          Node        `json:"testexpr,omitempty"`
+	ParamIds          *List       `json:"param_ids,omitempty"`
+	PlanId            int         `json:"plan_id"`
+	PlanName          *string     `json:"plan_name,omitempty"`
+	FirstColType      Oid         `json:"first_col_type"`
+	FirstColTypmod    int32       `json:"first_col_typmod"`
+	FirstColCollation Oid         `json:"first_col_collation"`
+	UseHashTable      bool        `json:"use_hash_table"`
+	UnknownEqFalse    bool        `json:"unknown_eq_false"`
+	ParallelSafe      bool        `json:"parallel_safe"`
+	SetParam          *List       `json:"set_param,omitempty"`
+	ParParam          *List       `json:"par_param,omitempty"`
+	Args              *List       `json:"args,omitempty"`
+	StartupCost       Cost        `json:"startup_cost"`
+	PerCallCost       Cost        `json:"per_call_cost"`
 }
 
 func (n *SubPlan) Pos() int {
diff --git a/internal/sql/ast/table_func.go b/internal/sql/ast/table_func.go
index 615ff82074..d2a22e365e 100644
--- a/internal/sql/ast/table_func.go
+++ b/internal/sql/ast/table_func.go
@@ -1,19 +1,21 @@
 package ast
 
 type TableFunc struct {
-	NsUris        *List
-	NsNames       *List
-	Docexpr       Node
-	Rowexpr       Node
-	Colnames      *List
-	Coltypes      *List
-	Coltypmods    *List
-	Colcollations *List
-	Colexprs      *List
-	Coldefexprs   *List
-	Notnulls      []uint32
-	Ordinalitycol int
-	Location      int
+	Tag NodeTag[TableFunc] `json:"tag"`
+
+	NsUris        *List    `json:"ns_uris,omitempty"`
+	NsNames       *List    `json:"ns_names,omitempty"`
+	Docexpr       Node     `json:"docexpr,omitempty"`
+	Rowexpr       Node     `json:"rowexpr,omitempty"`
+	Colnames      *List    `json:"colnames,omitempty"`
+	Coltypes      *List    `json:"coltypes,omitempty"`
+	Coltypmods    *List    `json:"coltypmods,omitempty"`
+	Colcollations *List    `json:"colcollations,omitempty"`
+	Colexprs      *List    `json:"colexprs,omitempty"`
+	Coldefexprs   *List    `json:"coldefexprs,omitempty"`
+	Notnulls      []uint32 `json:"notnulls,omitempty"`
+	Ordinalitycol int      `json:"ordinalitycol"`
+	Location      int      `json:"location"`
 }
 
 func (n *TableFunc) Pos() int {
diff --git a/internal/sql/ast/table_like_clause.go b/internal/sql/ast/table_like_clause.go
index 338065f3a2..8a5af1d5e2 100644
--- a/internal/sql/ast/table_like_clause.go
+++ b/internal/sql/ast/table_like_clause.go
@@ -1,8 +1,10 @@
 package ast
 
 type TableLikeClause struct {
-	Relation *RangeVar
-	Options  uint32
+	Tag NodeTag[TableLikeClause] `json:"tag"`
+
+	Relation *RangeVar `json:"relation,omitempty"`
+	Options  uint32    `json:"options"`
 }
 
 func (n *TableLikeClause) Pos() int {
diff --git a/internal/sql/ast/table_name.go b/internal/sql/ast/table_name.go
index 4f494a67e0..1dfe61fd4f 100644
--- a/internal/sql/ast/table_name.go
+++ b/internal/sql/ast/table_name.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type TableName struct {
-	Catalog string
-	Schema  string
-	Name    string
+	Tag NodeTag[TableName] `json:"tag"`
+
+	Catalog string `json:"catalog"`
+	Schema  string `json:"schema"`
+	Name    string `json:"name"`
 }
 
 func (n *TableName) Pos() int {
diff --git a/internal/sql/ast/table_sample_clause.go b/internal/sql/ast/table_sample_clause.go
index b92f731430..c8d05779ea 100644
--- a/internal/sql/ast/table_sample_clause.go
+++ b/internal/sql/ast/table_sample_clause.go
@@ -1,9 +1,11 @@
 package ast
 
 type TableSampleClause struct {
-	Tsmhandler Oid
-	Args       *List
-	Repeatable Node
+	Tag NodeTag[TableSampleClause] `json:"tag"`
+
+	Tsmhandler Oid   `json:"tsmhandler"`
+	Args       *List `json:"args,omitempty"`
+	Repeatable Node  `json:"repeatable,omitempty"`
 }
 
 func (n *TableSampleClause) Pos() int {
diff --git a/internal/sql/ast/target_entry.go b/internal/sql/ast/target_entry.go
index c9f72184e8..eeb5a33d00 100644
--- a/internal/sql/ast/target_entry.go
+++ b/internal/sql/ast/target_entry.go
@@ -1,14 +1,16 @@
 package ast
 
 type TargetEntry struct {
-	Xpr             Node
-	Expr            Node
-	Resno           AttrNumber
-	Resname         *string
-	Ressortgroupref Index
-	Resorigtbl      Oid
-	Resorigcol      AttrNumber
-	Resjunk         bool
+	Tag NodeTag[TargetEntry] `json:"tag"`
+
+	Xpr             Node       `json:"xpr,omitempty"`
+	Expr            Node       `json:"expr,omitempty"`
+	Resno           AttrNumber `json:"resno"`
+	Resname         *string    `json:"resname,omitempty"`
+	Ressortgroupref Index      `json:"ressortgroupref"`
+	Resorigtbl      Oid        `json:"resorigtbl"`
+	Resorigcol      AttrNumber `json:"resorigcol"`
+	Resjunk         bool       `json:"resjunk"`
 }
 
 func (n *TargetEntry) Pos() int {
diff --git a/internal/sql/ast/todo.go b/internal/sql/ast/todo.go
index 88e05e1ccf..c9b9d054f1 100644
--- a/internal/sql/ast/todo.go
+++ b/internal/sql/ast/todo.go
@@ -1,6 +1,7 @@
 package ast
 
 type TODO struct {
+	Tag NodeTag[TODO] `json:"tag"`
 }
 
 func (n *TODO) Pos() int {
diff --git a/internal/sql/ast/transaction_stmt.go b/internal/sql/ast/transaction_stmt.go
index a6bf4bdf83..60dbe32e0d 100644
--- a/internal/sql/ast/transaction_stmt.go
+++ b/internal/sql/ast/transaction_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type TransactionStmt struct {
-	Kind    TransactionStmtKind
-	Options *List
-	Gid     *string
+	Tag NodeTag[TransactionStmt] `json:"tag"`
+
+	Kind    TransactionStmtKind `json:"kind"`
+	Options *List               `json:"options,omitempty"`
+	Gid     *string             `json:"gid,omitempty"`
 }
 
 func (n *TransactionStmt) Pos() int {
diff --git a/internal/sql/ast/trigger_transition.go b/internal/sql/ast/trigger_transition.go
index 376745067a..1d09a9547d 100644
--- a/internal/sql/ast/trigger_transition.go
+++ b/internal/sql/ast/trigger_transition.go
@@ -1,9 +1,11 @@
 package ast
 
 type TriggerTransition struct {
-	Name    *string
-	IsNew   bool
-	IsTable bool
+	Tag NodeTag[TriggerTransition] `json:"tag"`
+
+	Name    *string `json:"name,omitempty"`
+	IsNew   bool    `json:"is_new"`
+	IsTable bool    `json:"is_table"`
 }
 
 func (n *TriggerTransition) Pos() int {
diff --git a/internal/sql/ast/truncate_stmt.go b/internal/sql/ast/truncate_stmt.go
index 6636e9f9e8..9a7a21dee1 100644
--- a/internal/sql/ast/truncate_stmt.go
+++ b/internal/sql/ast/truncate_stmt.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type TruncateStmt struct {
-	Relations   *List
-	RestartSeqs bool
-	Behavior    DropBehavior
+	Tag NodeTag[TruncateStmt] `json:"tag"`
+
+	Relations   *List        `json:"relations,omitempty"`
+	RestartSeqs bool         `json:"restart_seqs"`
+	Behavior    DropBehavior `json:"behavior"`
 }
 
 func (n *TruncateStmt) Pos() int {
diff --git a/internal/sql/ast/type_cast.go b/internal/sql/ast/type_cast.go
index fe5b321abf..56c8fbb55f 100644
--- a/internal/sql/ast/type_cast.go
+++ b/internal/sql/ast/type_cast.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type TypeCast struct {
-	Arg      Node
-	TypeName *TypeName
-	Location int
+	Tag NodeTag[TypeCast] `json:"tag"`
+
+	Arg      Node      `json:"arg,omitempty"`
+	TypeName *TypeName `json:"type_name,omitempty"`
+	Location int       `json:"location"`
 }
 
 func (n *TypeCast) Pos() int {
diff --git a/internal/sql/ast/type_name.go b/internal/sql/ast/type_name.go
index 26ef4d6d2b..9a557707b8 100644
--- a/internal/sql/ast/type_name.go
+++ b/internal/sql/ast/type_name.go
@@ -3,24 +3,26 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type TypeName struct {
-	Catalog string
-	Schema  string
-	Name    string
+	Tag NodeTag[TypeName] `json:"tag"`
+
+	Catalog string `json:"catalog"`
+	Schema  string `json:"schema"`
+	Name    string `json:"name"`
 	// Spelling is the type as the author wrote it, when that differs from
 	// Name: SQLite folds the spaces out of multi-word type names ("VARYING
 	// CHARACTER" resolves as "VARYINGCHARACTER" in the catalog), so the
 	// formatter prints this back instead of the folded form.
-	Spelling string
+	Spelling string `json:"spelling"`
 
 	// From pg.TypeName
-	Names       *List
-	TypeOid     Oid
-	Setof       bool
-	PctType     bool
-	Typmods     *List
-	Typemod     int32
-	ArrayBounds *List
-	Location    int
+	Names       *List `json:"names,omitempty"`
+	TypeOid     Oid   `json:"type_oid"`
+	Setof       bool  `json:"setof"`
+	PctType     bool  `json:"pct_type"`
+	Typmods     *List `json:"typmods,omitempty"`
+	Typemod     int32 `json:"typemod"`
+	ArrayBounds *List `json:"array_bounds,omitempty"`
+	Location    int   `json:"location"`
 }
 
 func (n *TypeName) Pos() int {
diff --git a/internal/sql/ast/unlisten_stmt.go b/internal/sql/ast/unlisten_stmt.go
index ca74e055f8..8c57881ca4 100644
--- a/internal/sql/ast/unlisten_stmt.go
+++ b/internal/sql/ast/unlisten_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type UnlistenStmt struct {
-	Conditionname *string
+	Tag NodeTag[UnlistenStmt] `json:"tag"`
+
+	Conditionname *string `json:"conditionname,omitempty"`
 }
 
 func (n *UnlistenStmt) Pos() int {
diff --git a/internal/sql/ast/update_stmt.go b/internal/sql/ast/update_stmt.go
index 55775a6624..dc154cfd35 100644
--- a/internal/sql/ast/update_stmt.go
+++ b/internal/sql/ast/update_stmt.go
@@ -7,16 +7,18 @@ import (
 )
 
 type UpdateStmt struct {
-	Relations     *List
-	TargetList    *List
-	WhereClause   Node
-	FromClause    *List
-	LimitCount    Node
-	ReturningList *List
-	WithClause    *WithClause
+	Tag NodeTag[UpdateStmt] `json:"tag"`
+
+	Relations     *List       `json:"relations,omitempty"`
+	TargetList    *List       `json:"target_list,omitempty"`
+	WhereClause   Node        `json:"where_clause,omitempty"`
+	FromClause    *List       `json:"from_clause,omitempty"`
+	LimitCount    Node        `json:"limit_count,omitempty"`
+	ReturningList *List       `json:"returning_list,omitempty"`
+	WithClause    *WithClause `json:"with_clause,omitempty"`
 	// PostgreSQL 18 RETURNING WITH (OLD AS ..., NEW AS ...) aliases
-	ReturningOldAlias string
-	ReturningNewAlias string
+	ReturningOldAlias string `json:"returning_old_alias"`
+	ReturningNewAlias string `json:"returning_new_alias"`
 }
 
 func (n *UpdateStmt) Pos() int {
diff --git a/internal/sql/ast/vacuum_stmt.go b/internal/sql/ast/vacuum_stmt.go
index 942fb762b2..c04ebc6662 100644
--- a/internal/sql/ast/vacuum_stmt.go
+++ b/internal/sql/ast/vacuum_stmt.go
@@ -1,9 +1,11 @@
 package ast
 
 type VacuumStmt struct {
-	Options  int
-	Relation *RangeVar
-	VaCols   *List
+	Tag NodeTag[VacuumStmt] `json:"tag"`
+
+	Options  int       `json:"options"`
+	Relation *RangeVar `json:"relation,omitempty"`
+	VaCols   *List     `json:"va_cols,omitempty"`
 }
 
 func (n *VacuumStmt) Pos() int {
diff --git a/internal/sql/ast/var.go b/internal/sql/ast/var.go
index 0d558180cb..97d707f999 100644
--- a/internal/sql/ast/var.go
+++ b/internal/sql/ast/var.go
@@ -1,16 +1,18 @@
 package ast
 
 type Var struct {
-	Xpr         Node
-	Varno       Index
-	Varattno    AttrNumber
-	Vartype     Oid
-	Vartypmod   int32
-	Varcollid   Oid
-	Varlevelsup Index
-	Varnoold    Index
-	Varoattno   AttrNumber
-	Location    int
+	Tag NodeTag[Var] `json:"tag"`
+
+	Xpr         Node       `json:"xpr,omitempty"`
+	Varno       Index      `json:"varno"`
+	Varattno    AttrNumber `json:"varattno"`
+	Vartype     Oid        `json:"vartype"`
+	Vartypmod   int32      `json:"vartypmod"`
+	Varcollid   Oid        `json:"varcollid"`
+	Varlevelsup Index      `json:"varlevelsup"`
+	Varnoold    Index      `json:"varnoold"`
+	Varoattno   AttrNumber `json:"varoattno"`
+	Location    int        `json:"location"`
 }
 
 func (n *Var) Pos() int {
diff --git a/internal/sql/ast/variable_expr.go b/internal/sql/ast/variable_expr.go
index 83223b482b..84026a1103 100644
--- a/internal/sql/ast/variable_expr.go
+++ b/internal/sql/ast/variable_expr.go
@@ -5,8 +5,10 @@ import "github.com/sqlc-dev/sqlc/internal/sql/format"
 // VariableExpr represents a MySQL user variable (e.g., @user_id)
 // This is distinct from sqlc's @param named parameter syntax.
 type VariableExpr struct {
-	Name     string
-	Location int
+	Tag NodeTag[VariableExpr] `json:"tag"`
+
+	Name     string `json:"name"`
+	Location int    `json:"location"`
 }
 
 func (n *VariableExpr) Pos() int {
diff --git a/internal/sql/ast/variable_set_stmt.go b/internal/sql/ast/variable_set_stmt.go
index 9307152293..74cf712b7f 100644
--- a/internal/sql/ast/variable_set_stmt.go
+++ b/internal/sql/ast/variable_set_stmt.go
@@ -1,10 +1,12 @@
 package ast
 
 type VariableSetStmt struct {
-	Kind    VariableSetKind
-	Name    *string
-	Args    *List
-	IsLocal bool
+	Tag NodeTag[VariableSetStmt] `json:"tag"`
+
+	Kind    VariableSetKind `json:"kind"`
+	Name    *string         `json:"name,omitempty"`
+	Args    *List           `json:"args,omitempty"`
+	IsLocal bool            `json:"is_local"`
 }
 
 func (n *VariableSetStmt) Pos() int {
diff --git a/internal/sql/ast/variable_show_stmt.go b/internal/sql/ast/variable_show_stmt.go
index c1dc7e95ef..e697115229 100644
--- a/internal/sql/ast/variable_show_stmt.go
+++ b/internal/sql/ast/variable_show_stmt.go
@@ -1,7 +1,9 @@
 package ast
 
 type VariableShowStmt struct {
-	Name *string
+	Tag NodeTag[VariableShowStmt] `json:"tag"`
+
+	Name *string `json:"name,omitempty"`
 }
 
 func (n *VariableShowStmt) Pos() int {
diff --git a/internal/sql/ast/view_stmt.go b/internal/sql/ast/view_stmt.go
index be93733f72..ec99b66730 100644
--- a/internal/sql/ast/view_stmt.go
+++ b/internal/sql/ast/view_stmt.go
@@ -1,12 +1,14 @@
 package ast
 
 type ViewStmt struct {
-	View            *RangeVar
-	Aliases         *List
-	Query           Node
-	Replace         bool
-	Options         *List
-	WithCheckOption ViewCheckOption
+	Tag NodeTag[ViewStmt] `json:"tag"`
+
+	View            *RangeVar       `json:"view,omitempty"`
+	Aliases         *List           `json:"aliases,omitempty"`
+	Query           Node            `json:"query,omitempty"`
+	Replace         bool            `json:"replace"`
+	Options         *List           `json:"options,omitempty"`
+	WithCheckOption ViewCheckOption `json:"with_check_option"`
 }
 
 func (n *ViewStmt) Pos() int {
diff --git a/internal/sql/ast/window_clause.go b/internal/sql/ast/window_clause.go
index 0a2f082f01..6f5a826c51 100644
--- a/internal/sql/ast/window_clause.go
+++ b/internal/sql/ast/window_clause.go
@@ -1,15 +1,17 @@
 package ast
 
 type WindowClause struct {
-	Name            *string
-	Refname         *string
-	PartitionClause *List
-	OrderClause     *List
-	FrameOptions    int
-	StartOffset     Node
-	EndOffset       Node
-	Winref          Index
-	CopiedOrder     bool
+	Tag NodeTag[WindowClause] `json:"tag"`
+
+	Name            *string `json:"name,omitempty"`
+	Refname         *string `json:"refname,omitempty"`
+	PartitionClause *List   `json:"partition_clause,omitempty"`
+	OrderClause     *List   `json:"order_clause,omitempty"`
+	FrameOptions    int     `json:"frame_options"`
+	StartOffset     Node    `json:"start_offset,omitempty"`
+	EndOffset       Node    `json:"end_offset,omitempty"`
+	Winref          Index   `json:"winref"`
+	CopiedOrder     bool    `json:"copied_order"`
 }
 
 func (n *WindowClause) Pos() int {
diff --git a/internal/sql/ast/window_def.go b/internal/sql/ast/window_def.go
index caba3e643c..7a04800353 100644
--- a/internal/sql/ast/window_def.go
+++ b/internal/sql/ast/window_def.go
@@ -3,14 +3,16 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type WindowDef struct {
-	Name            *string
-	Refname         *string
-	PartitionClause *List
-	OrderClause     *List
-	FrameOptions    int
-	StartOffset     Node
-	EndOffset       Node
-	Location        int
+	Tag NodeTag[WindowDef] `json:"tag"`
+
+	Name            *string `json:"name,omitempty"`
+	Refname         *string `json:"refname,omitempty"`
+	PartitionClause *List   `json:"partition_clause,omitempty"`
+	OrderClause     *List   `json:"order_clause,omitempty"`
+	FrameOptions    int     `json:"frame_options"`
+	StartOffset     Node    `json:"start_offset,omitempty"`
+	EndOffset       Node    `json:"end_offset,omitempty"`
+	Location        int     `json:"location"`
 }
 
 func (n *WindowDef) Pos() int {
diff --git a/internal/sql/ast/window_func.go b/internal/sql/ast/window_func.go
index eb0ba5c968..4202b48f79 100644
--- a/internal/sql/ast/window_func.go
+++ b/internal/sql/ast/window_func.go
@@ -1,17 +1,19 @@
 package ast
 
 type WindowFunc struct {
-	Xpr         Node
-	Winfnoid    Oid
-	Wintype     Oid
-	Wincollid   Oid
-	Inputcollid Oid
-	Args        *List
-	Aggfilter   Node
-	Winref      Index
-	Winstar     bool
-	Winagg      bool
-	Location    int
+	Tag NodeTag[WindowFunc] `json:"tag"`
+
+	Xpr         Node  `json:"xpr,omitempty"`
+	Winfnoid    Oid   `json:"winfnoid"`
+	Wintype     Oid   `json:"wintype"`
+	Wincollid   Oid   `json:"wincollid"`
+	Inputcollid Oid   `json:"inputcollid"`
+	Args        *List `json:"args,omitempty"`
+	Aggfilter   Node  `json:"aggfilter,omitempty"`
+	Winref      Index `json:"winref"`
+	Winstar     bool  `json:"winstar"`
+	Winagg      bool  `json:"winagg"`
+	Location    int   `json:"location"`
 }
 
 func (n *WindowFunc) Pos() int {
diff --git a/internal/sql/ast/with_check_option.go b/internal/sql/ast/with_check_option.go
index b622db4753..416c92d0e7 100644
--- a/internal/sql/ast/with_check_option.go
+++ b/internal/sql/ast/with_check_option.go
@@ -1,11 +1,13 @@
 package ast
 
 type WithCheckOption struct {
-	Kind     WCOKind
-	Relname  *string
-	Polname  *string
-	Qual     Node
-	Cascaded bool
+	Tag NodeTag[WithCheckOption] `json:"tag"`
+
+	Kind     WCOKind `json:"kind"`
+	Relname  *string `json:"relname,omitempty"`
+	Polname  *string `json:"polname,omitempty"`
+	Qual     Node    `json:"qual,omitempty"`
+	Cascaded bool    `json:"cascaded"`
 }
 
 func (n *WithCheckOption) Pos() int {
diff --git a/internal/sql/ast/with_clause.go b/internal/sql/ast/with_clause.go
index a7d4b24903..0124661b59 100644
--- a/internal/sql/ast/with_clause.go
+++ b/internal/sql/ast/with_clause.go
@@ -3,9 +3,11 @@ package ast
 import "github.com/sqlc-dev/sqlc/internal/sql/format"
 
 type WithClause struct {
-	Ctes      *List
-	Recursive bool
-	Location  int
+	Tag NodeTag[WithClause] `json:"tag"`
+
+	Ctes      *List `json:"ctes,omitempty"`
+	Recursive bool  `json:"recursive"`
+	Location  int   `json:"location"`
 }
 
 func (n *WithClause) Pos() int {
diff --git a/internal/sql/ast/xml_expr.go b/internal/sql/ast/xml_expr.go
index cbd82b3653..42497118a9 100644
--- a/internal/sql/ast/xml_expr.go
+++ b/internal/sql/ast/xml_expr.go
@@ -1,16 +1,18 @@
 package ast
 
 type XmlExpr struct {
-	Xpr       Node
-	Op        XmlExprOp
-	Name      *string
-	NamedArgs *List
-	ArgNames  *List
-	Args      *List
-	Xmloption XmlOptionType
-	Type      Oid
-	Typmod    int32
-	Location  int
+	Tag NodeTag[XmlExpr] `json:"tag"`
+
+	Xpr       Node          `json:"xpr,omitempty"`
+	Op        XmlExprOp     `json:"op"`
+	Name      *string       `json:"name,omitempty"`
+	NamedArgs *List         `json:"named_args,omitempty"`
+	ArgNames  *List         `json:"arg_names,omitempty"`
+	Args      *List         `json:"args,omitempty"`
+	Xmloption XmlOptionType `json:"xmloption"`
+	Type      Oid           `json:"type"`
+	Typmod    int32         `json:"typmod"`
+	Location  int           `json:"location"`
 }
 
 func (n *XmlExpr) Pos() int {
diff --git a/internal/sql/ast/xml_serialize.go b/internal/sql/ast/xml_serialize.go
index 32e4cc476d..e514db5480 100644
--- a/internal/sql/ast/xml_serialize.go
+++ b/internal/sql/ast/xml_serialize.go
@@ -1,10 +1,12 @@
 package ast
 
 type XmlSerialize struct {
-	Xmloption XmlOptionType
-	Expr      Node
-	TypeName  *TypeName
-	Location  int
+	Tag NodeTag[XmlSerialize] `json:"tag"`
+
+	Xmloption XmlOptionType `json:"xmloption"`
+	Expr      Node          `json:"expr,omitempty"`
+	TypeName  *TypeName     `json:"type_name,omitempty"`
+	Location  int           `json:"location"`
 }
 
 func (n *XmlSerialize) Pos() int {