feat(zod-openapi): Zod openapi zod v3 and v4

.changeset/late-toes-refuse.md

@@ -0,0 +1,5 @@
+---
+'@hono/zod-openapi': minor
+---
+
+Added support for zod v4

packages/zod-openapi/package.json

@@ -41,7 +41,7 @@
   "homepage": "https://github.com/honojs/middleware",
   "peerDependencies": {
     "hono": ">=4.3.6",
-    "zod": ">=3.0.0"
+    "zod": "^3.25.0 || ^4.0.0"
   },
   "devDependencies": {
     "@arethetypeswrong/cli": "^0.17.4",
@@ -51,10 +51,10 @@
     "typescript": "^5.8.2",
     "vitest": "^3.2.4",
     "yaml": "^2.4.3",
-    "zod": "^3.22.1"
+    "zod": "^4.0.5"
   },
   "dependencies": {
-    "@asteasolutions/zod-to-openapi": "^7.3.0",
+    "@asteasolutions/zod-to-openapi": "^8",
     "@hono/zod-validator": "workspace:^",
     "openapi3-ts": "^4.5.0"
   },

packages/zod-openapi/src/index.test-d.ts

@@ -232,15 +232,15 @@ describe('coerce', () => {
       }),
       (c) => {
         const { id } = c.req.valid('param')
-        assertType<number>(id)
+        assertType<unknown>(id)
         return c.json({ id })
       }
     )
 
     type Actual = ExtractSchema<typeof routes>['/api/users/:id']['$get']['input']
     type Expected = {
       param: {
-        id: number
+        id: unknown
       }
     }
     type verify = Expect<Equal<Expected, Actual>>

packages/zod-openapi/src/index.ts

@@ -11,6 +11,7 @@ import {
   OpenApiGeneratorV3,
   OpenApiGeneratorV31,
   extendZodWithOpenApi,
+  getOpenApiMetadata,
 } from '@asteasolutions/zod-to-openapi'
 import { zValidator } from '@hono/zod-validator'
 import { Hono } from 'hono'
@@ -38,8 +39,19 @@ import type { JSONParsed, JSONValue, RemoveBlankRecord, SimplifyDeepArray } from
 import { mergePath } from 'hono/utils/url'
 import type { OpenAPIObject } from 'openapi3-ts/oas30'
 import type { OpenAPIObject as OpenAPIV31bject } from 'openapi3-ts/oas31'
-import type { ZodError, ZodSchema } from 'zod'
-import { ZodType, z } from 'zod'
+import * as z3 from 'zod/v3'
+import * as z4 from 'zod/v4/core'
+import * as z from 'zod/v4'
+
+type ZodType = z3.ZodTypeAny | z4.$ZodType
+type ZodError<T extends ZodType> = T extends z4.$ZodType ? z4.$ZodError : z3.ZodError
+type ZodInput<T> = T extends z3.ZodType ? z3.input<T> : T extends z4.$ZodType ? z4.input<T> : never
+type ZodOutput<T> = T extends z3.ZodType
+  ? z3.output<T>
+  : T extends z4.$ZodType
+    ? z4.output<T>
+    : never
+type ZodInfer<T> = T extends z3.ZodType ? z3.infer<T> : T extends z4.$ZodType ? z4.infer<T> : never
 
 type MaybePromise<T> = Promise<T> | T
 
@@ -110,13 +122,13 @@ type InputTypeBase<
         in: {
           [K in Type]: HasUndefined<ValidationTargets[K]> extends true
             ? {
-                [K2 in keyof z.input<RequestPart<R, Part>>]?: z.input<RequestPart<R, Part>>[K2]
+                [K2 in keyof ZodInput<RequestPart<R, Part>>]?: ZodInput<RequestPart<R, Part>>[K2]
               }
             : {
-                [K2 in keyof z.input<RequestPart<R, Part>>]: z.input<RequestPart<R, Part>>[K2]
+                [K2 in keyof ZodInput<RequestPart<R, Part>>]: ZodInput<RequestPart<R, Part>>[K2]
               }
         }
-        out: { [K in Type]: z.output<RequestPart<R, Part>> }
+        out: { [K in Type]: ZodOutput<RequestPart<R, Part>> }
       }
     : {}
   : {}
@@ -128,16 +140,16 @@ type InputTypeJson<R extends RouteConfig> = R['request'] extends RequestTypes
         ? {}
         : R['request']['body']['content'][keyof R['request']['body']['content']] extends Record<
               'schema',
-              ZodSchema<any>
+              ZodType
             >
           ? {
               in: {
-                json: z.input<
+                json: ZodInput<
                   R['request']['body']['content'][keyof R['request']['body']['content']]['schema']
                 >
               }
               out: {
-                json: z.output<
+                json: ZodOutput<
                   R['request']['body']['content'][keyof R['request']['body']['content']]['schema']
                 >
               }
@@ -154,16 +166,16 @@ type InputTypeForm<R extends RouteConfig> = R['request'] extends RequestTypes
         ? {}
         : R['request']['body']['content'][keyof R['request']['body']['content']] extends Record<
               'schema',
-              ZodSchema<any>
+              ZodType
             >
           ? {
               in: {
-                form: z.input<
+                form: ZodInput<
                   R['request']['body']['content'][keyof R['request']['body']['content']]['schema']
                 >
               }
               out: {
-                form: z.output<
+                form: ZodOutput<
                   R['request']['body']['content'][keyof R['request']['body']['content']]['schema']
                 >
               }
@@ -181,8 +193,8 @@ type InputTypeCookie<R extends RouteConfig> = InputTypeBase<R, 'cookies', 'cooki
 type ExtractContent<T> = T extends {
   [K in keyof T]: infer A
 }
-  ? A extends Record<'schema', ZodSchema>
-    ? z.infer<A['schema']>
+  ? A extends Record<'schema', ZodType>
+    ? ZodInfer<A['schema']>
     : never
   : never
 
@@ -230,7 +242,7 @@ export type Hook<T, E extends Env, P extends string, R> = (
       }
     | {
         success: false
-        error: ZodError
+        error: ZodError<any>
       }
   ),
   c: Context<E, P>
@@ -499,7 +511,7 @@ export class OpenAPIHono<
           continue
         }
         const schema = (bodyContent[mediaType] as ZodMediaTypeObject)['schema']
-        if (!(schema instanceof ZodType)) {
+        if (!(schema instanceof z4.$ZodType || schema instanceof z3.ZodType)) {
           continue
         }
         if (isJSONContentType(mediaType)) {
@@ -659,11 +671,14 @@ export class OpenAPIHono<
         }
 
         case 'schema':
-          return this.openAPIRegistry.register(def.schema._def.openapi._internal.refId, def.schema)
+          return this.openAPIRegistry.register(
+            getOpenApiMetadata(def.schema)._internal?.refId,
+            def.schema
+          )
 
         case 'parameter':
           return this.openAPIRegistry.registerParameter(
-            def.schema._def.openapi._internal.refId,
+            getOpenApiMetadata(def.schema)._internal?.refId,
             def.schema
           )
 

yarn.lock

@@ -99,14 +99,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@asteasolutions/zod-to-openapi@npm:^7.3.0":
-  version: 7.3.0
-  resolution: "@asteasolutions/zod-to-openapi@npm:7.3.0"
+"@asteasolutions/zod-to-openapi@npm:^8":
+  version: 8.0.0
+  resolution: "@asteasolutions/zod-to-openapi@npm:8.0.0"
   dependencies:
     openapi3-ts: "npm:^4.1.2"
   peerDependencies:
-    zod: ^3.20.2
-  checksum: 10c0/f0a68a89929cdeaa3e21d2027489689f982824d676a9332c680e119f60881dd39b571324b24ad4837fda49bf6fe7c3e2af2199268b281bf1aec923d7a7cbfc40
+    zod: ^4.0.0
+  checksum: 10c0/b522d074832fb137dca724c8bd4bb134c7b4d4cad12c247ed3c864f993923b3475fc06580e6e1cbc4fd8641cd361679bbe1dd87c9bb42e142bc056d96d59fbc8
   languageName: node
   linkType: hard
 
@@ -2734,7 +2734,7 @@ __metadata:
   resolution: "@hono/zod-openapi@workspace:packages/zod-openapi"
   dependencies:
     "@arethetypeswrong/cli": "npm:^0.17.4"
-    "@asteasolutions/zod-to-openapi": "npm:^7.3.0"
+    "@asteasolutions/zod-to-openapi": "npm:^8"
     "@hono/zod-validator": "workspace:^"
     hono: "npm:^4.8.4"
     openapi3-ts: "npm:^4.5.0"
@@ -2743,10 +2743,10 @@ __metadata:
     typescript: "npm:^5.8.2"
     vitest: "npm:^3.2.4"
     yaml: "npm:^2.4.3"
-    zod: "npm:^3.22.1"
+    zod: "npm:^4.0.5"
   peerDependencies:
     hono: ">=4.3.6"
-    zod: ">=3.0.0"
+    zod: ^3.25.0 || ^4.0.0
   languageName: unknown
   linkType: soft
 
@@ -16830,7 +16830,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"zod@npm:^3.20.2, zod@npm:^3.22.1, zod@npm:^3.22.3":
+"zod@npm:^3.20.2, zod@npm:^3.22.3":
   version: 3.24.2
   resolution: "zod@npm:3.24.2"
   checksum: 10c0/c638c7220150847f13ad90635b3e7d0321b36cce36f3fc6050ed960689594c949c326dfe2c6fa87c14b126ee5d370ccdebd6efb304f41ef5557a4aaca2824565