diff --git a/lib/config/builder/builder.ts b/lib/config/builder/builder.ts
index 8843660..56e1034 100644
--- a/lib/config/builder/builder.ts
+++ b/lib/config/builder/builder.ts
@@ -1,5 +1,3 @@
-import { typeFromProps } from "../../util";
-
 export class IBuilder<A> {
   protected constructor(readonly a: A) { }
 
diff --git a/lib/config/builder/list.ts b/lib/config/builder/list.ts
index f8a7788..619be93 100644
--- a/lib/config/builder/list.ts
+++ b/lib/config/builder/list.ts
@@ -1,6 +1,5 @@
 import { BuilderExtract, IBuilder } from "./builder";
 import { Config } from "./config";
-import { Variants } from "./variants";
 import {
   InputSpec,
   UniqueBy,
@@ -107,47 +106,6 @@ export class List<A extends ValueSpecList> extends IBuilder<A> {
       ...value,
     });
   }
-  static union<
-    A extends {
-      name: string;
-      description: string | null;
-      warning: string | null;
-      default: Record<string, unknown>[];
-      range: string;
-      spec: {
-        select: {
-          name: string;
-          description: string | null;
-          warning: string | null;
-        }
-        variants: Variants<{
-          [key: string]: { name: string; spec: InputSpec };
-        }>;
-        displayAs: null | string;
-        uniqueBy: UniqueBy;
-        default: string;
-      };
-    }
-  >(a: A) {
-    const { spec: previousSpec, ...rest } = a;
-    const { variants: previousVariants, ...restSpec } = previousSpec;
-    const variants = previousVariants.build() as BuilderExtract<
-      A["spec"]["variants"]
-    >;
-    const spec = {
-      ...restSpec,
-      variants,
-    };
-    const value = {
-      spec,
-      ...rest,
-    };
-    return new List({
-      type: "list" as const,
-      subtype: "union" as const,
-      ...value,
-    });
-  }
 
   public validator() {
     return guardAll(this.a);
diff --git a/lib/config/builder/value.ts b/lib/config/builder/value.ts
index 763c425..cca028b 100644
--- a/lib/config/builder/value.ts
+++ b/lib/config/builder/value.ts
@@ -7,7 +7,6 @@ import {
   ValueSpec,
   ValueSpecList,
   ValueSpecNumber,
-  ValueSpecOf,
   ValueSpecString,
 } from "../config-types";
 import { guardAll } from "../../util";
@@ -146,8 +145,10 @@ export class Value<A extends ValueSpec> extends IBuilder<A> {
       name: string;
       description: string | null;
       warning: string | null;
+      selectKey: string;
       variants: Variants<{ [key: string]: { name: string; spec: InputSpec } }>;
-      default: string;
+      nullable: boolean;
+      default: string | null;
     }
   >(a: A) {
     const { variants: previousVariants, ...rest } = a;
diff --git a/lib/config/config-types.ts b/lib/config/config-types.ts
index b9a18ec..b25fe18 100644
--- a/lib/config/config-types.ts
+++ b/lib/config/config-types.ts
@@ -66,13 +66,13 @@ export interface ValueSpecBoolean extends WithStandalone {
 
 export interface ValueSpecUnion extends WithStandalone {
   type: "union";
-  variants: { [key: string]: { name: string; spec: InputSpec } };
-  default: null | string;
+  selectKey: string;
+  nullable: boolean
+  variants: Record<string, { name: string; spec: InputSpec }>;
 }
 
 export interface ValueSpecFile extends WithStandalone {
   type: "file";
-  placeholder: null | string;
   nullable: boolean;
   extensions: string[];
 }
@@ -89,11 +89,10 @@ export interface WithStandalone {
 }
 
 export interface SelectBase {
-  values: { [value: string]: string };
+  values: Record<string, string>;
 }
 
-/**  no lists of booleans, lists*/
-export type ListValueSpecType = "string" | "number" | "object" | "union";
+export type ListValueSpecType = "string" | "number" | "object";
 
 /** represents a spec for the values of a list */
 export type ListValueSpecOf<T extends ListValueSpecType> = T extends "string"
@@ -102,8 +101,6 @@ export type ListValueSpecOf<T extends ListValueSpecType> = T extends "string"
   ? ListValueSpecNumber
   : T extends "object"
   ? ListValueSpecObject
-  : T extends "union"
-  ? ListValueSpecUnion
   : never;
 
 /** represents a spec for a list */
@@ -163,19 +160,4 @@ export type UniqueBy =
   | { any: readonly UniqueBy[] | UniqueBy[] }
   | { all: readonly UniqueBy[] | UniqueBy[] };
 
-export interface ListValueSpecUnion {
-  select: {
-    name: string
-    description: null | string
-    warning: null | string
-  }
-  variants: { [key: string]: { name: string; spec: InputSpec } };
-  /** a handlebars template for labeling each union list item */
-  displayAs: null | string;
-  /** indicates whether duplicates can be permitted in the list */
-  uniqueBy: UniqueBy;
-  /** the default variant when creating a new union instance in the list*/
-  default: null | string;
-}
-
 export type DefaultString = string | { charset: string; len: number };
diff --git a/scripts/oldSpecToBuilder.ts b/scripts/oldSpecToBuilder.ts
index 31a9423..30e05f6 100644
--- a/scripts/oldSpecToBuilder.ts
+++ b/scripts/oldSpecToBuilder.ts
@@ -228,17 +228,17 @@ export default async function makeFileContent(
           convertInputSpec(value.spec.spec)
         );
         return `List.obj({
-        name: ${JSON.stringify(value.name || null)},
-        range: ${JSON.stringify(value.range || null)},
-        spec: {
-            spec: ${specName},
-            displayAs: ${JSON.stringify(value?.spec?.["display-as"] || null)},
-            uniqueBy: ${JSON.stringify(value?.spec?.["unique-by"] || null)},
-        },
-        default: ${JSON.stringify(value.default || null)},
-        description: ${JSON.stringify(value.description || null)},
-        warning: ${JSON.stringify(value.warning || null)},
-      })`;
+          name: ${JSON.stringify(value.name || null)},
+          range: ${JSON.stringify(value.range || null)},
+          spec: {
+              spec: ${specName},
+              displayAs: ${JSON.stringify(value?.spec?.["display-as"] || null)},
+              uniqueBy: ${JSON.stringify(value?.spec?.["unique-by"] || null)},
+          },
+          default: ${JSON.stringify(value.default || null)},
+          description: ${JSON.stringify(value.description || null)},
+          warning: ${JSON.stringify(value.warning || null)},
+        })`;
       }
       case "union": {
         const variants = newConst(
@@ -248,34 +248,37 @@ export default async function makeFileContent(
             value.spec["variant-names"] || {}
           )
         );
-        return `List.union(
-        {
-            name:${JSON.stringify(value.name || null)},
-            range:${JSON.stringify(value.range || null)},
+
+        return `List.obj({
+          name:${JSON.stringify(value.name || null)},
+          range:${JSON.stringify(value.range || null)},
+          spec: {
             spec: {
-                select: {
-                    "name": ${JSON.stringify(
-                      value?.spec?.tag?.["name"] || null
-                    )},
-                    "description": ${JSON.stringify(
-                      value?.spec?.tag?.["description"] || null
-                    )},
-                    "warning": ${JSON.stringify(
-                      value?.spec?.tag?.["warning"] || null
-                    )},
-                },
-                variants: ${variants},
-                displayAs: ${JSON.stringify(
-                  value?.spec?.["display-as"] || null
+              ${value?.spec?.tag?.id || 'type'}: {
+                type: "union",
+                name: ${JSON.stringify(
+                  value?.spec?.tag?.name || null
                 )},
-                uniqueBy: ${JSON.stringify(value?.spec?.["unique-by"] || null)},
-                default: ${JSON.stringify(value?.spec?.default || null)},
-            },
-            default: ${JSON.stringify(value.default || null)},
-            description: ${JSON.stringify(value.description || null)},
-            warning: ${JSON.stringify(value.warning || null)},
-          }
-      )`;
+                description: ${JSON.stringify(
+                  value?.spec?.tag?.description || null
+                )},
+                warning: ${JSON.stringify(
+                  value?.spec?.tag?.warning || null
+                )},
+                selectKey: ${JSON.stringify(
+                  value?.spec?.tag?.id || null
+                )},
+                variants: ${variants},
+                nullable: false,
+              }
+            }
+            displayAs: ${JSON.stringify(value?.spec?.["display-as"] || null)},
+            uniqueBy: ${JSON.stringify(value?.spec?.["unique-by"] || null)},
+          },
+          default: ${JSON.stringify(value.default || null)},
+          description: ${JSON.stringify(value.description || null)},
+          warning: ${JSON.stringify(value.warning || null)},
+        })`;
       }
     }
     throw new Error(`Unknown subtype "${value.subtype}"`);