From aa5a2e39608b54d4195cd39208c3e212fd340a18 Mon Sep 17 00:00:00 2001
From: callumjhays <callumjhays@gmail.com>
Date: Mon, 11 May 2026 15:02:15 +1000
Subject: [PATCH 1/3] fix(zod): generate z.discriminatedUnion for multi-value
 discriminator mappings
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When a discriminator maps multiple values to the same schema (e.g.
mapping: { one: '#/Bar', two: '#/Bar' }), tryBuildDiscriminatedUnion()
returned null because it only read .const from the discriminator property.
The IR stores multiple values as { logicalOperator: 'or', items: [...] },
which the function didn't handle, causing a silent fallback to z.union.

- Detect the logicalOperator: 'or' pattern and collect const values into
  an array
- Emit z.enum([...]) for multi-value members, z.literal(...) for single
- Add discriminator-mapped-many test scenario across all matrix cells
  (zod v3 + v4 × OpenAPI 3.0.x + 3.1.x)
- Fix changeset scope to plugin(zod) per contributing guide
---
 ...fix-zod-discriminated-union-multi-value.md |  5 +++++
 .../mini/discriminator-mapped-many/zod.gen.ts | 21 +++++++++++++++++++
 .../v3/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../v4/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../mini/discriminator-mapped-many/zod.gen.ts | 21 +++++++++++++++++++
 .../v3/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../v4/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../zod/v3/test/3.0.x.test.ts                 |  8 +++++++
 .../zod/v3/test/3.1.x.test.ts                 |  8 +++++++
 .../mini/discriminator-mapped-many/zod.gen.ts | 21 +++++++++++++++++++
 .../v3/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../v4/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../mini/discriminator-mapped-many/zod.gen.ts | 21 +++++++++++++++++++
 .../v3/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../v4/discriminator-mapped-many/zod.gen.ts   | 21 +++++++++++++++++++
 .../zod/v4/test/3.0.x.test.ts                 |  8 +++++++
 .../zod/v4/test/3.1.x.test.ts                 |  8 +++++++
 .../src/plugins/zod/mini/toAst/union.ts       |  4 +++-
 .../plugins/zod/shared/discriminated-union.ts | 11 +++++++++-
 .../src/plugins/zod/v3/toAst/union.ts         |  4 +++-
 .../src/plugins/zod/v4/toAst/union.ts         |  4 +++-
 21 files changed, 308 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/fix-zod-discriminated-union-multi-value.md
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts

diff --git a/.changeset/fix-zod-discriminated-union-multi-value.md b/.changeset/fix-zod-discriminated-union-multi-value.md
new file mode 100644
index 0000000000..ffba685734
--- /dev/null
+++ b/.changeset/fix-zod-discriminated-union-multi-value.md
@@ -0,0 +1,5 @@
+---
+'@hey-api/openapi-ts': patch
+---
+
+**plugin(zod)**: fix: generate z.discriminatedUnion when discriminator maps multiple values to the same schema
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..a7e388b534
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4-mini';
+
+export const zBar = z.object({
+    foo: z.optional(z.enum(['one', 'two']))
+});
+
+export const zBaz = z.object({
+    foo: z.optional(z.enum(['three']))
+});
+
+export const zSpæcial = z.object({
+    foo: z.optional(z.enum(['four']))
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    z.extend(zBar, { foo: z.enum(['one', 'two']) }),
+    z.extend(zBaz, { foo: z.literal('three') }),
+    z.extend(zSpæcial, { foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..5b51ab9abe
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..9994b91a08
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..a7e388b534
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4-mini';
+
+export const zBar = z.object({
+    foo: z.optional(z.enum(['one', 'two']))
+});
+
+export const zBaz = z.object({
+    foo: z.optional(z.enum(['three']))
+});
+
+export const zSpæcial = z.object({
+    foo: z.optional(z.enum(['four']))
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    z.extend(zBar, { foo: z.enum(['one', 'two']) }),
+    z.extend(zBaz, { foo: z.literal('three') }),
+    z.extend(zSpæcial, { foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..5b51ab9abe
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..9994b91a08
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts b/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts
index f498a05473..5510e42bab 100644
--- a/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts
@@ -34,6 +34,14 @@ for (const zodVersion of zodVersions) {
         }),
         description: 'generates circular schemas',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many.yaml',
+          output: 'discriminator-mapped-many',
+        }),
+        description:
+          'generates discriminated union when multiple mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts b/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts
index 5761d3ba64..2ed15ee169 100644
--- a/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts
@@ -152,6 +152,14 @@ for (const zodVersion of zodVersions) {
         }),
         description: 'handles oneOf discriminator (falls back to z.union when needed)',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many.yaml',
+          output: 'discriminator-mapped-many',
+        }),
+        description:
+          'generates discriminated union when multiple mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..a365be0f13
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/mini';
+
+export const zBar = z.object({
+    foo: z.optional(z.enum(['one', 'two']))
+});
+
+export const zBaz = z.object({
+    foo: z.optional(z.enum(['three']))
+});
+
+export const zSpæcial = z.object({
+    foo: z.optional(z.enum(['four']))
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    z.extend(zBar, { foo: z.enum(['one', 'two']) }),
+    z.extend(zBaz, { foo: z.literal('three') }),
+    z.extend(zSpæcial, { foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..1b25c19cad
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod/v3';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..facaac6e38
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..a365be0f13
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/mini';
+
+export const zBar = z.object({
+    foo: z.optional(z.enum(['one', 'two']))
+});
+
+export const zBaz = z.object({
+    foo: z.optional(z.enum(['three']))
+});
+
+export const zSpæcial = z.object({
+    foo: z.optional(z.enum(['four']))
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    z.extend(zBar, { foo: z.enum(['one', 'two']) }),
+    z.extend(zBaz, { foo: z.literal('three') }),
+    z.extend(zSpæcial, { foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..1b25c19cad
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod/v3';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts
new file mode 100644
index 0000000000..facaac6e38
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many/zod.gen.ts
@@ -0,0 +1,21 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod';
+
+export const zBar = z.object({
+    foo: z.enum(['one', 'two']).optional()
+});
+
+export const zBaz = z.object({
+    foo: z.enum(['three']).optional()
+});
+
+export const zSpæcial = z.object({
+    foo: z.enum(['four']).optional()
+});
+
+export const zFoo = z.discriminatedUnion('foo', [
+    zBar.extend({ foo: z.enum(['one', 'two']) }),
+    zBaz.extend({ foo: z.literal('three') }),
+    zSpæcial.extend({ foo: z.literal('four') })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts b/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts
index 18659712b5..136861b51d 100644
--- a/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts
@@ -42,6 +42,14 @@ for (const zodVersion of zodVersions) {
         description:
           'falls back to z.union() when discriminated union members have allOf (intersection)',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many.yaml',
+          output: 'discriminator-mapped-many',
+        }),
+        description:
+          'generates discriminated union when multiple mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts b/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts
index 703c51f7ab..27104ef815 100644
--- a/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts
@@ -185,6 +185,14 @@ for (const zodVersion of zodVersions) {
         }),
         description: 'handles oneOf discriminator (falls back to z.union when needed)',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many.yaml',
+          output: 'discriminator-mapped-many',
+        }),
+        description:
+          'generates discriminated union when multiple mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts b/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts
index 183ce382c8..a2fc98417e 100644
--- a/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts
+++ b/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts
@@ -49,7 +49,9 @@ function baseNode(ctx: UnionResolverContext): Chain {
           member.refExpression,
           $.object().prop(
             discriminatedExpression.discriminatorKey,
-            $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
+            Array.isArray(member.discriminatedValue)
+              ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
+              : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
           ),
         ),
     );
diff --git a/packages/openapi-ts/src/plugins/zod/shared/discriminated-union.ts b/packages/openapi-ts/src/plugins/zod/shared/discriminated-union.ts
index 4e85cc1a13..f98153fe55 100644
--- a/packages/openapi-ts/src/plugins/zod/shared/discriminated-union.ts
+++ b/packages/openapi-ts/src/plugins/zod/shared/discriminated-union.ts
@@ -40,7 +40,16 @@ export function tryBuildDiscriminatedUnion({
     if (schema.logicalOperator !== 'and' || !schema.items || schema.items.length !== 2) return null;
 
     const refPart = schema.items[1]!;
-    const discriminatedValue = schema.items[0]!.properties?.[discriminatorKey]?.const;
+    const discriminatorProp = schema.items[0]!.properties?.[discriminatorKey];
+    let discriminatedValue: unknown;
+    if (discriminatorProp?.const !== undefined) {
+      discriminatedValue = discriminatorProp.const;
+    } else if (
+      discriminatorProp?.logicalOperator === 'or' &&
+      discriminatorProp.items?.every((item) => item.const !== undefined)
+    ) {
+      discriminatedValue = discriminatorProp.items.map((item) => item.const);
+    }
 
     // lazy references can't be used in a discriminated union directly
     if (discriminatedValue === undefined || items[index]!.meta.hasLazy) return null;
diff --git a/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts b/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts
index d588b84f28..2b85eb5815 100644
--- a/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts
+++ b/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts
@@ -48,7 +48,9 @@ function baseNode(ctx: UnionResolverContext): Chain {
         .call(
           $.object().prop(
             discriminatedExpression.discriminatorKey,
-            $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
+            Array.isArray(member.discriminatedValue)
+              ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
+              : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
           ),
         ),
     );
diff --git a/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts b/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts
index 7ec7667344..e1486cea74 100644
--- a/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts
+++ b/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts
@@ -46,7 +46,9 @@ function baseNode(ctx: UnionResolverContext): Chain {
           .call(
             $.object().prop(
               discriminatedExpression.discriminatorKey,
-              $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
+              Array.isArray(member.discriminatedValue)
+                ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
+                : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
             ),
           ),
       );

From cef8ae517dd744de544cb13d8eba6f2b2f9e15a6 Mon Sep 17 00:00:00 2001
From: callumjhays <callumjhays@gmail.com>
Date: Mon, 11 May 2026 16:16:20 +1000
Subject: [PATCH 2/3] test(zod): add failing test for number-typed
 discriminator in mapped-many
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add OpenAPI specs and test scenarios for discriminator mappings where
multiple integer values map to the same schema. The generated snapshots
intentionally contain `z.enum([1, 2])` which is invalid — z.enum only
accepts string tuples — demonstrating the type-safety gap fixed in the
next commit.
---
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod/v3/test/3.0.x.test.ts                 |  8 +++++
 .../zod/v3/test/3.1.x.test.ts                 |  8 +++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod.gen.ts                                | 16 ++++++++++
 .../zod/v4/test/3.0.x.test.ts                 |  8 +++++
 .../zod/v4/test/3.1.x.test.ts                 |  8 +++++
 .../discriminator-mapped-many-number.yaml     | 31 +++++++++++++++++++
 .../discriminator-mapped-many-number.yaml     | 31 +++++++++++++++++++
 18 files changed, 286 insertions(+)
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
 create mode 100644 specs/3.0.x/discriminator-mapped-many-number.yaml
 create mode 100644 specs/3.1.x/discriminator-mapped-many-number.yaml

diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..5535ccfc18
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4-mini';
+
+export const zBar = z.object({
+    code: z.optional(z.union([z.literal(1), z.literal(2)]))
+});
+
+export const zBaz = z.object({
+    code: z.optional(z.literal(3))
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBaz, { code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..6c7182a26f
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..29df77e7c5
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..5535ccfc18
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4-mini';
+
+export const zBar = z.object({
+    code: z.optional(z.union([z.literal(1), z.literal(2)]))
+});
+
+export const zBaz = z.object({
+    code: z.optional(z.literal(3))
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBaz, { code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..6c7182a26f
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..29df77e7c5
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/v4';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts b/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts
index 5510e42bab..d2418c0cb3 100644
--- a/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v3/test/3.0.x.test.ts
@@ -42,6 +42,14 @@ for (const zodVersion of zodVersions) {
         description:
           'generates discriminated union when multiple mapping values point to same schema',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many-number.yaml',
+          output: 'discriminator-mapped-many-number',
+        }),
+        description:
+          'generates discriminated union when multiple number mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts b/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts
index 2ed15ee169..ed01c96e5f 100644
--- a/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v3/test/3.1.x.test.ts
@@ -160,6 +160,14 @@ for (const zodVersion of zodVersions) {
         description:
           'generates discriminated union when multiple mapping values point to same schema',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many-number.yaml',
+          output: 'discriminator-mapped-many-number',
+        }),
+        description:
+          'generates discriminated union when multiple number mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..6cd7c118e6
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/mini';
+
+export const zBar = z.object({
+    code: z.optional(z.union([z.literal(1), z.literal(2)]))
+});
+
+export const zBaz = z.object({
+    code: z.optional(z.literal(3))
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBaz, { code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..b64f5341fd
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod/v3';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..4287ed1b42
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..6cd7c118e6
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod/mini';
+
+export const zBar = z.object({
+    code: z.optional(z.union([z.literal(1), z.literal(2)]))
+});
+
+export const zBaz = z.object({
+    code: z.optional(z.literal(3))
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBaz, { code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..b64f5341fd
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import { z } from 'zod/v3';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
new file mode 100644
index 0000000000..4287ed1b42
--- /dev/null
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -0,0 +1,16 @@
+// This file is auto-generated by @hey-api/openapi-ts
+
+import * as z from 'zod';
+
+export const zBar = z.object({
+    code: z.union([z.literal(1), z.literal(2)]).optional()
+});
+
+export const zBaz = z.object({
+    code: z.literal(3).optional()
+});
+
+export const zFoo = z.discriminatedUnion('code', [
+    zBar.extend({ code: z.enum([1, 2]) }),
+    zBaz.extend({ code: z.literal(3) })
+]);
diff --git a/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts b/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts
index 136861b51d..0d004290f3 100644
--- a/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v4/test/3.0.x.test.ts
@@ -50,6 +50,14 @@ for (const zodVersion of zodVersions) {
         description:
           'generates discriminated union when multiple mapping values point to same schema',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many-number.yaml',
+          output: 'discriminator-mapped-many-number',
+        }),
+        description:
+          'generates discriminated union when multiple number mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts b/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts
index 27104ef815..3232387292 100644
--- a/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts
+++ b/packages/openapi-ts-tests/zod/v4/test/3.1.x.test.ts
@@ -193,6 +193,14 @@ for (const zodVersion of zodVersions) {
         description:
           'generates discriminated union when multiple mapping values point to same schema',
       },
+      {
+        config: createConfig({
+          input: 'discriminator-mapped-many-number.yaml',
+          output: 'discriminator-mapped-many-number',
+        }),
+        description:
+          'generates discriminated union when multiple number mapping values point to same schema',
+      },
       {
         config: createConfig({
           input: 'enum-null.json',
diff --git a/specs/3.0.x/discriminator-mapped-many-number.yaml b/specs/3.0.x/discriminator-mapped-many-number.yaml
new file mode 100644
index 0000000000..6c5fc9e8ba
--- /dev/null
+++ b/specs/3.0.x/discriminator-mapped-many-number.yaml
@@ -0,0 +1,31 @@
+openapi: 3.0.0
+info:
+  title: OpenAPI 3.0.0 discriminator mapped many (number) example
+  version: 1
+components:
+  schemas:
+    Foo:
+      oneOf:
+        - $ref: '#/components/schemas/Bar'
+        - $ref: '#/components/schemas/Baz'
+      discriminator:
+        propertyName: code
+        mapping:
+          '1': '#/components/schemas/Bar'
+          '2': '#/components/schemas/Bar'
+          '3': '#/components/schemas/Baz'
+    Bar:
+      type: object
+      properties:
+        code:
+          type: integer
+          enum:
+            - 1
+            - 2
+    Baz:
+      type: object
+      properties:
+        code:
+          type: integer
+          enum:
+            - 3
diff --git a/specs/3.1.x/discriminator-mapped-many-number.yaml b/specs/3.1.x/discriminator-mapped-many-number.yaml
new file mode 100644
index 0000000000..54fa8ae32e
--- /dev/null
+++ b/specs/3.1.x/discriminator-mapped-many-number.yaml
@@ -0,0 +1,31 @@
+openapi: 3.1.0
+info:
+  title: OpenAPI 3.1.0 discriminator mapped many (number) example
+  version: 1
+components:
+  schemas:
+    Foo:
+      oneOf:
+        - $ref: '#/components/schemas/Bar'
+        - $ref: '#/components/schemas/Baz'
+      discriminator:
+        propertyName: code
+        mapping:
+          '1': '#/components/schemas/Bar'
+          '2': '#/components/schemas/Bar'
+          '3': '#/components/schemas/Baz'
+    Bar:
+      type: object
+      properties:
+        code:
+          type: integer
+          enum:
+            - 1
+            - 2
+    Baz:
+      type: object
+      properties:
+        code:
+          type: integer
+          enum:
+            - 3

From 38101c47afe888174d63840f4444956b1a35d53b Mon Sep 17 00:00:00 2001
From: callumjhays <callumjhays@gmail.com>
Date: Mon, 11 May 2026 16:18:02 +1000
Subject: [PATCH 3/3] fix(zod): use z.union of z.literal for non-string
 multi-value discriminators

z.enum only accepts [string, ...string[]], so emitting z.enum([1, 2]) for
integer discriminator values is a TypeScript type error. When a discriminated
union member maps to multiple non-string values, emit
z.union([z.literal(v1), z.literal(v2)]) instead.

Fixes the array branch in v3, v4, and mini union emitters.
---
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../zod.gen.ts                                |  2 +-
 .../src/plugins/zod/mini/toAst/union.ts       | 12 +++++++++-
 .../src/plugins/zod/v3/toAst/union.ts         | 24 ++++++++++++-------
 .../src/plugins/zod/v4/toAst/union.ts         | 24 ++++++++++++-------
 15 files changed, 55 insertions(+), 29 deletions(-)

diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
index 5535ccfc18..b3327ba5b3 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBar, { code: z.union([z.literal(1), z.literal(2)]) }),
     z.extend(zBaz, { code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
index 6c7182a26f..d8148660c1 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
index 29df77e7c5..0417778aea 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
index 5535ccfc18..b3327ba5b3 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBar, { code: z.union([z.literal(1), z.literal(2)]) }),
     z.extend(zBaz, { code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
index 6c7182a26f..d8148660c1 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
index 29df77e7c5..0417778aea 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
index 6cd7c118e6..5fc0bdc133 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBar, { code: z.union([z.literal(1), z.literal(2)]) }),
     z.extend(zBaz, { code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
index b64f5341fd..da2629c131 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
index 4287ed1b42..b11c5e2390 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
index 6cd7c118e6..5fc0bdc133 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    z.extend(zBar, { code: z.enum([1, 2]) }),
+    z.extend(zBar, { code: z.union([z.literal(1), z.literal(2)]) }),
     z.extend(zBaz, { code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
index b64f5341fd..da2629c131 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
index 4287ed1b42..b11c5e2390 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/discriminator-mapped-many-number/zod.gen.ts
@@ -11,6 +11,6 @@ export const zBaz = z.object({
 });
 
 export const zFoo = z.discriminatedUnion('code', [
-    zBar.extend({ code: z.enum([1, 2]) }),
+    zBar.extend({ code: z.union([z.literal(1), z.literal(2)]) }),
     zBaz.extend({ code: z.literal(3) })
 ]);
diff --git a/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts b/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts
index a2fc98417e..45cc711726 100644
--- a/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts
+++ b/packages/openapi-ts/src/plugins/zod/mini/toAst/union.ts
@@ -50,7 +50,17 @@ function baseNode(ctx: UnionResolverContext): Chain {
           $.object().prop(
             discriminatedExpression.discriminatorKey,
             Array.isArray(member.discriminatedValue)
-              ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
+              ? member.discriminatedValue.every((v) => typeof v === 'string')
+                ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
+                : $(z)
+                    .attr(identifiers.union)
+                    .call(
+                      $.array(
+                        ...member.discriminatedValue.map((v) =>
+                          $(z).attr(identifiers.literal).call($.fromValue(v)),
+                        ),
+                      ),
+                    )
               : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
           ),
         ),
diff --git a/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts b/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts
index 2b85eb5815..0536cbe3f9 100644
--- a/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts
+++ b/packages/openapi-ts/src/plugins/zod/v3/toAst/union.ts
@@ -43,16 +43,24 @@ function baseNode(ctx: UnionResolverContext): Chain {
 
   if (discriminatedExpression) {
     const unionMembers = discriminatedExpression.members.map((member) =>
-      member.refExpression
-        .attr(identifiers.extend)
-        .call(
-          $.object().prop(
-            discriminatedExpression.discriminatorKey,
-            Array.isArray(member.discriminatedValue)
+      member.refExpression.attr(identifiers.extend).call(
+        $.object().prop(
+          discriminatedExpression.discriminatorKey,
+          Array.isArray(member.discriminatedValue)
+            ? member.discriminatedValue.every((v) => typeof v === 'string')
               ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
-              : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
-          ),
+              : $(z)
+                  .attr(identifiers.union)
+                  .call(
+                    $.array(
+                      ...member.discriminatedValue.map((v) =>
+                        $(z).attr(identifiers.literal).call($.fromValue(v)),
+                      ),
+                    ),
+                  )
+            : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
         ),
+      ),
     );
 
     return $(z)
diff --git a/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts b/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts
index e1486cea74..a6e8078c11 100644
--- a/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts
+++ b/packages/openapi-ts/src/plugins/zod/v4/toAst/union.ts
@@ -41,16 +41,24 @@ function baseNode(ctx: UnionResolverContext): Chain {
 
     if (discriminatedExpression) {
       const unionMembers = discriminatedExpression.members.map((member) =>
-        member.refExpression
-          .attr(identifiers.extend)
-          .call(
-            $.object().prop(
-              discriminatedExpression.discriminatorKey,
-              Array.isArray(member.discriminatedValue)
+        member.refExpression.attr(identifiers.extend).call(
+          $.object().prop(
+            discriminatedExpression.discriminatorKey,
+            Array.isArray(member.discriminatedValue)
+              ? member.discriminatedValue.every((v) => typeof v === 'string')
                 ? $(z).attr(identifiers.enum).call($.fromValue(member.discriminatedValue))
-                : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
-            ),
+                : $(z)
+                    .attr(identifiers.union)
+                    .call(
+                      $.array(
+                        ...member.discriminatedValue.map((v) =>
+                          $(z).attr(identifiers.literal).call($.fromValue(v)),
+                        ),
+                      ),
+                    )
+              : $(z).attr(identifiers.literal).call($.fromValue(member.discriminatedValue)),
           ),
+        ),
       );
 
       expression = $(z)