diff --git a/examples/simple/spec.ts b/examples/simple/spec.ts
index 2d34494..9478f76 100644
--- a/examples/simple/spec.ts
+++ b/examples/simple/spec.ts
@@ -3,12 +3,17 @@ import { DefineApiEndpoints, FetchT } from "../../src";
 export type PathMap = DefineApiEndpoints<{
   "/users": {
     get: {
-      resBody: {
-        200: { userNames: string[] };
-        400: { errorMessage: string };
-      };
       headers: { "Content-Type": "application/json" };
-      resHeaders: { "Content-Type": "application/json" };
+      responses: {
+        200: {
+          body: { userNames: string[] };
+          headers: { "Content-Type": "application/json" };
+        };
+        400: {
+          body: { errorMessage: string };
+          headers: { "Content-Type": "application/json" };
+        };
+      };
     };
   };
 }>;
diff --git a/examples/spec/valibot.ts b/examples/spec/valibot.ts
index 7a45f33..2cd6069 100644
--- a/examples/spec/valibot.ts
+++ b/examples/spec/valibot.ts
@@ -10,29 +10,34 @@ export const pathMap = {
       query: v.object({
         page: v.string(),
       }),
-      resBody: {
-        200: v.object({ userNames: v.array(v.string()) }),
-        400: v.object({ errorMessage: v.string() }),
+      responses: {
+        200: { body: v.object({ userNames: v.array(v.string()) }) },
+        400: { body: v.object({ errorMessage: v.string() }) },
       },
     },
     post: {
       headers: JsonHeader,
-      resHeaders: JsonHeader,
-      resBody: {
-        200: v.object({ userId: v.string() }),
-        400: v.object({ errorMessage: v.string() }),
-      },
       body: v.object({
         userName: v.string(),
       }),
+      responses: {
+        200: {
+          headers: JsonHeader,
+          body: v.object({ userId: v.string() }),
+        },
+        400: {
+          headers: JsonHeader,
+          body: v.object({ errorMessage: v.string() }),
+        },
+      },
     },
   },
   "/users/:userId": {
     get: {
       params: v.object({ userId: v.string() }),
-      resBody: {
-        200: v.object({ userName: v.string() }),
-        400: v.object({ errorMessage: v.string() }),
+      responses: {
+        200: { body: v.object({ userName: v.string() }) },
+        400: { body: v.object({ errorMessage: v.string() }) },
       },
     },
   },
diff --git a/examples/spec/zod.ts b/examples/spec/zod.ts
index 26f17ed..00a41fa 100644
--- a/examples/spec/zod.ts
+++ b/examples/spec/zod.ts
@@ -11,17 +11,22 @@ export const pathMap = {
       query: z.object({
         page: z.string(),
       }),
-      resBody: {
-        200: z.object({ userNames: z.string().array() }),
-        400: z.object({ errorMessage: z.string() }),
+      responses: {
+        200: { body: z.object({ userNames: z.string().array() }) },
+        400: { body: z.object({ errorMessage: z.string() }) },
       },
     },
     post: {
       headers: JsonHeader,
-      resHeaders: JsonHeader,
-      resBody: {
-        200: z.object({ userId: z.string() }),
-        400: z.object({ errorMessage: z.string() }),
+      responses: {
+        200: {
+          headers: JsonHeader,
+          body: z.object({ userId: z.string() }),
+        },
+        400: {
+          headers: JsonHeader,
+          body: z.object({ errorMessage: z.string() }),
+        },
       },
       body: z.object({
         userName: z.string(),
@@ -31,9 +36,9 @@ export const pathMap = {
   "/users/:userId": {
     get: {
       params: z.object({ userId: z.string() }),
-      resBody: {
-        200: z.object({ userName: z.string() }),
-        400: z.object({ errorMessage: z.string() }),
+      responses: {
+        200: { body: z.object({ userName: z.string() }) },
+        400: { body: z.object({ errorMessage: z.string() }) },
       },
     },
   },
diff --git a/src/common/spec.ts b/src/common/spec.ts
index 53d1a49..c35f5ba 100644
--- a/src/common/spec.ts
+++ b/src/common/spec.ts
@@ -42,16 +42,14 @@ export interface BaseApiSpec<
   Query,
   Body,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  ResBody,
   RequestHeaders,
-  ResponseHeaders,
+  Responses extends AnyApiResponses,
 > {
   query?: Query;
   params?: Params;
   body?: Body;
-  resBody: ResBody;
+  responses: Responses;
   headers?: RequestHeaders;
-  resHeaders?: ResponseHeaders;
 }
 export type ApiSpec<
   ParamKeys extends string = string,
@@ -62,16 +60,11 @@ export type ApiSpec<
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   Query extends Record<string, string> = Record<string, any>,
   Body extends object = object,
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  ResBody extends Partial<Record<StatusCode, any>> = Partial<
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    Record<StatusCode, any>
-  >,
   RequestHeaders extends Record<string, string> = Record<string, string>,
-  ResponseHeaders extends Record<string, string> = Record<string, string>,
-> = BaseApiSpec<Params, Query, Body, ResBody, RequestHeaders, ResponseHeaders>;
+  Responses extends AnyApiResponses = AnyApiResponses,
+> = BaseApiSpec<Params, Query, Body, RequestHeaders, Responses>;
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export type AnyApiSpec = BaseApiSpec<any, any, any, any, any, any>;
+export type AnyApiSpec = BaseApiSpec<any, any, any, any, any>;
 
 type JsonHeader = {
   "Content-Type": "application/json";
@@ -82,7 +75,10 @@ type WithJsonHeader<H extends Record<string, string> | undefined> =
 
 type AsJsonApiSpec<AS extends ApiSpec> = Omit<AS, "headers" | "resHeaders"> & {
   headers: WithJsonHeader<AS["headers"]>;
-  resHeaders: WithJsonHeader<AS["resHeaders"]>;
+  // FIXME: いい感じにマージが必要
+  // response: {
+  //   headers: WithJsonHeader<AS["response"]["headers"]>;
+  // };
 };
 
 export type ApiP<
@@ -115,19 +111,24 @@ export type ApiHasP<
   : never;
 
 export type ApiRes<
-  AResponses extends ApiResponses,
+  AResponses extends AnyApiResponses,
   SC extends keyof AResponses & StatusCode,
-  Res = object,
-> = AResponses[SC] extends Res ? AResponses[SC] : never;
-export type ApiResponses<Res = object> = Partial<Record<StatusCode, Res>>;
-export type ApiClientResponses<AResponses extends ApiResponses> = {
+> = AResponses[SC] extends AnyResponse ? AResponses[SC]["body"] : undefined;
+export type AnyApiResponses = DefineApiResponses<AnyResponse>;
+export type DefineApiResponses<Response extends AnyResponse> = Partial<
+  Record<StatusCode, Response>
+>;
+export type DefineResponse<Body, Headers> = { body: Body; headers?: Headers };
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type AnyResponse = DefineResponse<any, any>;
+export type ApiClientResponses<AResponses extends AnyApiResponses> = {
   [SC in keyof AResponses & StatusCode]: ClientResponse<
     ApiRes<AResponses, SC>,
     SC,
     "json"
   >;
 };
-export type MergeApiResponses<AR extends ApiResponses> =
+export type MergeApiResponseBodies<AR extends AnyApiResponses> =
   ApiClientResponses<AR>[keyof ApiClientResponses<AR>];
 
 /**
diff --git a/src/express/index.ts b/src/express/index.ts
index 3562af5..8bc4fab 100644
--- a/src/express/index.ts
+++ b/src/express/index.ts
@@ -1,5 +1,12 @@
 import { IRouter, RequestHandler } from "express";
-import { Method, ApiResponses, ApiRes, ApiSpec, ApiEndpoints } from "../index";
+import {
+  Method,
+  AnyApiResponses,
+  ApiRes,
+  ApiSpec,
+  AnyApiSpec,
+  AnyApiEndpoints,
+} from "../index";
 import {
   NextFunction,
   ParamsDictionary,
@@ -27,12 +34,12 @@ export type Handler<
 > = (
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   req: Request<ParamsDictionary, any, any, ParsedQs, Locals>,
-  res: ExpressResponse<NonNullable<Spec>["resBody"], 200, Locals>,
+  res: ExpressResponse<NonNullable<Spec>["responses"], 200, Locals>,
   next: NextFunction,
 ) => void;
 
 export type ToHandler<
-  Spec extends ApiSpec | undefined,
+  Spec extends AnyApiSpec | undefined,
   Validators extends AnyValidators | undefined,
 > = Handler<
   Spec,
@@ -41,7 +48,7 @@ export type ToHandler<
   >
 >;
 
-export type ToHandlers<E extends ApiEndpoints, V extends ValidatorsMap> = {
+export type ToHandlers<E extends AnyApiEndpoints, V extends ValidatorsMap> = {
   [Path in keyof E & string]: {
     [M in Method]: ToHandler<E[Path][M], V[Path][M]>;
   };
@@ -51,7 +58,7 @@ export type ToHandlers<E extends ApiEndpoints, V extends ValidatorsMap> = {
  * Express Response, but with more strict type information.
  */
 export type ExpressResponse<
-  Responses extends ApiResponses,
+  Responses extends AnyApiResponses,
   SC extends keyof Responses & StatusCode,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   LocalsObj extends Record<string, any> = Record<string, any>,
@@ -69,7 +76,7 @@ export type ValidateLocals<Vs extends AnyValidators | Record<string, never>> = {
  * Express Router, but with more strict type information.
  */
 export type RouterT<
-  E extends ApiEndpoints,
+  E extends AnyApiEndpoints,
   V extends ValidatorsMap,
   SC extends StatusCode = StatusCode,
 > = Omit<IRouter, Method> & {
diff --git a/src/express/valibot.test.ts b/src/express/valibot.test.ts
index b63acec..c4a2f65 100644
--- a/src/express/valibot.test.ts
+++ b/src/express/valibot.test.ts
@@ -42,14 +42,18 @@ describe("valibot", () => {
           params: v.object({
             name: v.string(),
           }),
-          resBody: {
-            200: v.object({
-              id: v.string(),
-              name: v.string(),
-            }),
-            400: v.object({
-              message: v.string(),
-            }),
+          responses: {
+            200: {
+              body: v.object({
+                id: v.string(),
+                name: v.string(),
+              }),
+            },
+            400: {
+              body: v.object({
+                message: v.string(),
+              }),
+            },
           },
         },
       },
@@ -293,11 +297,14 @@ describe("valibot", () => {
     const pathMap = {
       "/users": {
         get: {
-          resBody: { 200: v.array(User) },
+          responses: { 200: { body: v.array(User) } },
         },
         post: {
           body: UserName,
-          resBody: { 200: User, ...BadRequest },
+          responses: {
+            200: { body: User, ...BadRequest },
+            400: { body: Err },
+          },
         },
       },
       "/users/:id": {
@@ -309,7 +316,10 @@ describe("valibot", () => {
           query: v.object({
             detail: v.union([v.literal("true"), v.literal("false")]),
           }),
-          resBody: { 200: User, ...BadRequest },
+          responses: {
+            200: { body: User, ...BadRequest },
+            400: { body: Err },
+          },
         },
       },
     } satisfies ValibotApiEndpoints;
@@ -417,22 +427,26 @@ describe("valibot", () => {
           get: {
             params: v.object({ active: v.string() }),
             query: v.object({ name: v.string() }),
-            resBody: {
-              200: v.array(
-                v.object({
-                  id: v.string(),
-                  name: v.string(),
-                  active: v.string(),
-                }),
-              ),
-              400: v.object({ message: v.string() }),
+            responses: {
+              200: {
+                body: v.array(
+                  v.object({
+                    id: v.string(),
+                    name: v.string(),
+                    active: v.string(),
+                  }),
+                ),
+              },
+              400: { body: v.object({ message: v.string() }) },
             },
           },
           post: {
             body: v.object({ name: v.string() }),
-            resBody: {
-              200: v.array(v.object({ id: v.string(), name: v.string() })),
-              400: v.object({ message: v.string() }),
+            responses: {
+              200: {
+                body: v.array(v.object({ id: v.string(), name: v.string() })),
+              },
+              400: { body: v.object({ message: v.string() }) },
             },
           },
         },
diff --git a/src/express/zod.test.ts b/src/express/zod.test.ts
index 16943f7..ea07c27 100644
--- a/src/express/zod.test.ts
+++ b/src/express/zod.test.ts
@@ -35,14 +35,18 @@ describe("validatorMiddleware", () => {
         params: z.object({
           name: z.string(),
         }),
-        resBody: {
-          200: z.object({
-            id: z.string(),
-            name: z.string(),
-          }),
-          400: z.object({
-            message: z.string(),
-          }),
+        responses: {
+          200: {
+            body: z.object({
+              id: z.string(),
+              name: z.string(),
+            }),
+          },
+          400: {
+            body: z.object({
+              message: z.string(),
+            }),
+          },
         },
       },
     },
@@ -237,15 +241,15 @@ describe("typed", () => {
   const UserName = z.object({ name: z.string() });
   const User = UserName.merge(UserId);
   const Err = z.object({ message: z.string() });
-  const BadRequest = { 400: Err };
+  const BadRequest = { 400: { body: Err } };
   const pathMap = {
     "/users": {
       get: {
-        resBody: { 200: z.array(User) },
+        responses: { 200: { body: z.array(User) } },
       },
       post: {
         body: UserName,
-        resBody: { 200: User, ...BadRequest },
+        responses: { 200: { body: User }, ...BadRequest },
       },
     },
     "/users/:id": {
@@ -257,7 +261,10 @@ describe("typed", () => {
         query: z.object({
           detail: z.union([z.literal("true"), z.literal("false")]),
         }),
-        resBody: { 200: User, ...BadRequest },
+        responses: {
+          200: { body: User },
+          ...BadRequest,
+        },
       },
     },
   } satisfies ZodApiEndpoints;
@@ -365,22 +372,26 @@ describe("Handler", () => {
         get: {
           params: z.object({ active: z.string() }),
           query: z.object({ name: z.string() }),
-          resBody: {
-            200: z.array(
-              z.object({
-                id: z.string(),
-                name: z.string(),
-                active: z.string(),
-              }),
-            ),
-            400: z.object({ message: z.string() }),
+          responses: {
+            200: {
+              body: z.array(
+                z.object({
+                  id: z.string(),
+                  name: z.string(),
+                  active: z.string(),
+                }),
+              ),
+            },
+            400: { body: z.object({ message: z.string() }) },
           },
         },
         post: {
           body: z.object({ name: z.string() }),
-          resBody: {
-            200: z.array(z.object({ id: z.string(), name: z.string() })),
-            400: z.object({ message: z.string() }),
+          responses: {
+            200: {
+              body: z.array(z.object({ id: z.string(), name: z.string() })),
+            },
+            400: { body: z.object({ message: z.string() }) },
           },
         },
       },
diff --git a/src/fastify/zod.ts b/src/fastify/zod.ts
index e326e45..5c5b6ef 100644
--- a/src/fastify/zod.ts
+++ b/src/fastify/zod.ts
@@ -1,12 +1,27 @@
 import { ZodApiEndpoint, ZodApiEndpoints, ZodApiSpec } from "../zod";
-import { Method } from "../common";
+import { AnyApiResponses, Method, StatusCode } from "../common";
+
+const toFastifyResponse = <Responses extends AnyApiResponses>(
+  responses: Responses,
+): ToFastifyResponse<Responses> => {
+  const ret = { ...responses };
+  Object.keys(responses).forEach((key) => {
+    const sc = key as keyof Responses as StatusCode;
+    ret[sc] = responses[sc]!.body;
+  });
+  return ret as ToFastifyResponse<Responses>;
+};
+
+type ToFastifyResponse<Responses extends AnyApiResponses> = {
+  [SC in keyof Responses & StatusCode]: NonNullable<Responses[SC]>["body"];
+};
 
 type FastifySchema<Spec extends ZodApiSpec> = {
   querystring: Spec["query"];
   params: Spec["params"];
   body: Spec["body"];
   headers: Spec["headers"];
-  response: Spec["resBody"];
+  response: ToFastifyResponse<Spec["responses"]>;
 };
 export const toSchema = <Spec extends ZodApiSpec>(
   spec: Spec,
@@ -16,7 +31,7 @@ export const toSchema = <Spec extends ZodApiSpec>(
     params: spec.params,
     body: spec.body,
     headers: spec.headers,
-    response: spec.resBody,
+    response: toFastifyResponse(spec.responses),
   };
 };
 
diff --git a/src/fetch/index.t-test.ts b/src/fetch/index.t-test.ts
index d05c046..890d899 100644
--- a/src/fetch/index.t-test.ts
+++ b/src/fetch/index.t-test.ts
@@ -7,9 +7,7 @@ const JSONT = JSON as JSONT;
   type Spec = DefineApiEndpoints<{
     "/users": {
       get: {
-        resBody: {
-          200: { prop: string };
-        };
+        responses: { 200: { body: { prop: string } } };
       };
     };
   }>;
@@ -27,17 +25,15 @@ const JSONT = JSON as JSONT;
   type Spec = DefineApiEndpoints<{
     "/users": {
       get: {
-        resBody: {
-          200: { prop: string };
-        };
+        responses: { 200: { body: { prop: string } } };
       };
       post: {
         body: {
           userName: string;
         };
-        resBody: {
-          200: { postProp: string };
-          400: { error: string };
+        responses: {
+          200: { body: { postProp: string } };
+          400: { body: { error: string } };
         };
       };
     };
@@ -125,9 +121,7 @@ const JSONT = JSON as JSONT;
     "/users": {
       get: {
         headers: { Cookie: `a=${string}` };
-        resBody: {
-          200: { prop: string };
-        };
+        responses: { 200: { body: { prop: string } } };
       };
     };
   }>;
@@ -154,9 +148,7 @@ const JSONT = JSON as JSONT;
     "/packages/list": {
       get: {
         headers: { Cookie: `a=${string}` };
-        resBody: {
-          200: { prop: string };
-        };
+        responses: { 200: { body: { prop: string } } };
         query: {
           state: boolean;
         };
@@ -190,17 +182,13 @@ const JSONT = JSON as JSONT;
   type Spec = DefineApiEndpoints<{
     "/vectorize/indexes/:indexName": {
       post: {
-        resBody: {
-          200: { prop2: string };
-        };
+        responses: { 200: { body: { prop2: string } } };
       };
     };
     "/vectorize/indexes/:indexName/get-by-ids": {
       post: {
         body: { ids: string[] };
-        resBody: {
-          200: { prop: string };
-        };
+        responses: { 200: { body: { prop: string } } };
       };
     };
   }>;
diff --git a/src/fetch/index.ts b/src/fetch/index.ts
index 31fe745..bcc3294 100644
--- a/src/fetch/index.ts
+++ b/src/fetch/index.ts
@@ -2,11 +2,11 @@ import {
   ApiEndpoints,
   ApiHasP,
   ApiP,
-  ApiResponses,
+  AnyApiResponses,
   CaseInsensitiveMethod,
   FilterNever,
   MatchedPatterns,
-  MergeApiResponses,
+  MergeApiResponseBodies,
   Method,
   NormalizePath,
   ParseURL,
@@ -53,12 +53,21 @@ type FetchT<UrlPrefix extends UrlPrefixPattern, E extends ApiEndpoints> = <
     M,
     "query"
   >,
-  ResBody extends ApiP<E, CandidatePaths, M, "resBody"> = ApiP<
+  ResBody extends ApiP<
     E,
     CandidatePaths,
     M,
-    "resBody"
-  >,
+    "responses"
+  > extends AnyApiResponses
+    ? MergeApiResponseBodies<ApiP<E, CandidatePaths, M, "responses">>
+    : Record<StatusCode, never> = ApiP<
+    E,
+    CandidatePaths,
+    M,
+    "responses"
+  > extends AnyApiResponses
+    ? MergeApiResponseBodies<ApiP<E, CandidatePaths, M, "responses">>
+    : Record<StatusCode, never>,
 >(
   input: Input,
   init: ApiHasP<E, CandidatePaths, M> extends true
@@ -74,10 +83,6 @@ type FetchT<UrlPrefix extends UrlPrefixPattern, E extends ApiEndpoints> = <
             ApiP<E, CandidatePaths, M, "headers">
           >
         | undefined,
-) => Promise<
-  MergeApiResponses<
-    ResBody extends ApiResponses ? ResBody : Record<StatusCode, never>
-  >
->;
+) => Promise<ResBody>;
 
 export default FetchT;
diff --git a/src/valibot/index.ts b/src/valibot/index.ts
index cdab830..d5c4df6 100644
--- a/src/valibot/index.ts
+++ b/src/valibot/index.ts
@@ -1,5 +1,12 @@
 import * as v from "valibot";
-import { BaseApiSpec, Method, StatusCode } from "../common";
+import {
+  AnyApiResponses,
+  BaseApiSpec,
+  DefineApiResponses,
+  DefineResponse,
+  Method,
+  StatusCode,
+} from "../common";
 import {
   getApiSpec,
   Validator,
@@ -42,12 +49,9 @@ export type ValibotApiSpec<
   Params extends AnyV = AnyV,
   Query extends AnyV = AnyV,
   Body extends AnyV = AnyV,
-  ResBody extends Partial<Record<StatusCode, AnyV>> = Partial<
-    Record<StatusCode, AnyV>
-  >,
   RequestHeaders extends AnyV = AnyV,
-  ResponseHeaders extends AnyV = AnyV,
-> = BaseApiSpec<Params, Query, Body, ResBody, RequestHeaders, ResponseHeaders>;
+  Responses extends AnyApiResponses = AnyApiResponses,
+> = BaseApiSpec<Params, Query, Body, RequestHeaders, Responses>;
 export type ToApiEndpoints<E extends ValibotApiEndpoints> = {
   [Path in keyof E & string]: ToApiEndpoint<E, Path>;
 };
@@ -55,26 +59,28 @@ export type ToApiEndpoint<
   E extends ValibotApiEndpoints,
   Path extends keyof E,
 > = {
-  [M in keyof E[Path] & Method]: E[Path][M] extends undefined
-    ? undefined
-    : ToApiSpec<NonNullable<E[Path][M]>>;
+  [M in keyof E[Path] & Method]: ToApiSpec<NonNullable<E[Path][M]>>;
 };
 export type ToApiSpec<ZAS extends ValibotApiSpec> = {
   query: InferOrUndefined<ZAS["query"]>;
   params: InferOrUndefined<ZAS["params"]>;
   body: InferOrUndefined<ZAS["body"]>;
-  resBody: ToApiResponses<ZAS["resBody"]>;
   headers: InferOrUndefined<ZAS["headers"]>;
-  resHeaders: InferOrUndefined<ZAS["resHeaders"]>;
+  responses: ToApiResponses<ZAS["responses"]>;
+};
+export type ToApiResponses<AR extends ValibotAnyApiResponses> = {
+  [SC in keyof AR & StatusCode]: {
+    body: InferOrUndefined<NonNullable<AR[SC]>["body"]>;
+    headers: InferOrUndefined<NonNullable<AR[SC]>["headers"]>;
+  };
 };
+type ValibotAnyApiResponse = DefineResponse<AnyV, AnyV>;
+export type ValibotAnyApiResponses = DefineApiResponses<ValibotAnyApiResponse>;
 export type ValibotApiResponses = Partial<Record<StatusCode, AnyV>>;
 export type ValibotApiResSchema<
   AResponses extends ValibotApiResponses,
   SC extends keyof AResponses & StatusCode,
 > = AResponses[SC] extends AnyV ? AResponses[SC] : never;
-export type ToApiResponses<AR extends ValibotApiResponses> = {
-  [SC in keyof AR & StatusCode]: v.InferOutput<ValibotApiResSchema<AR, SC>>;
-};
 
 /**
  * Create a new validator for the given endpoints.
diff --git a/src/zod/index.ts b/src/zod/index.ts
index 44f2f1f..c70b27e 100644
--- a/src/zod/index.ts
+++ b/src/zod/index.ts
@@ -1,5 +1,11 @@
 import { SafeParseReturnType, z, ZodError, ZodType } from "zod";
-import { BaseApiSpec, Method, StatusCode } from "../common";
+import {
+  BaseApiSpec,
+  DefineApiResponses,
+  DefineResponse,
+  Method,
+  StatusCode,
+} from "../common";
 import {
   getApiSpec,
   Validator,
@@ -47,35 +53,31 @@ export type ZodApiSpec<
   >,
   Query extends z.ZodTypeAny = z.ZodTypeAny,
   Body extends z.ZodTypeAny = z.ZodTypeAny,
-  ResBody extends ZodApiResponses = Partial<Record<StatusCode, z.ZodTypeAny>>,
   RequestHeaders extends z.ZodTypeAny = z.ZodTypeAny,
-  ResponseHeaders extends z.ZodTypeAny = z.ZodTypeAny,
-> = BaseApiSpec<Params, Query, Body, ResBody, RequestHeaders, ResponseHeaders>;
-export type ZodApiResponses = Partial<Record<StatusCode, z.ZodTypeAny>>;
-export type ZodApiResSchema<
-  AResponses extends ZodApiResponses,
-  SC extends keyof AResponses & StatusCode,
-> = AResponses[SC] extends z.ZodTypeAny ? AResponses[SC] : never;
+  Responses extends ZodAnyApiResponses = ZodAnyApiResponses,
+> = BaseApiSpec<Params, Query, Body, RequestHeaders, Responses>;
+type ZodAnyApiResponse = DefineResponse<z.ZodTypeAny, z.ZodTypeAny>;
+export type ZodAnyApiResponses = DefineApiResponses<ZodAnyApiResponse>;
 
 // -- converter --
 export type ToApiEndpoints<E extends ZodApiEndpoints> = {
   [Path in keyof E & string]: ToApiEndpoint<E, Path>;
 };
 export type ToApiEndpoint<E extends ZodApiEndpoints, Path extends keyof E> = {
-  [M in keyof E[Path] & Method]: E[Path][M] extends undefined
-    ? undefined
-    : ToApiSpec<NonNullable<E[Path][M]>>;
+  [M in keyof E[Path] & Method]: ToApiSpec<NonNullable<E[Path][M]>>;
 };
 export type ToApiSpec<ZAS extends ZodApiSpec> = {
   query: InferOrUndefined<ZAS["query"]>;
   params: InferOrUndefined<ZAS["params"]>;
   body: InferOrUndefined<ZAS["body"]>;
-  resBody: ToApiResponses<ZAS["resBody"]>;
   headers: InferOrUndefined<ZAS["headers"]>;
-  resHeaders: InferOrUndefined<ZAS["resHeaders"]>;
+  responses: ToApiResponses<ZAS["responses"]>;
 };
-export type ToApiResponses<AR extends ZodApiResponses> = {
-  [SC in keyof AR & StatusCode]: z.infer<ZodApiResSchema<AR, SC>>;
+export type ToApiResponses<AR extends ZodAnyApiResponses> = {
+  [SC in keyof AR & StatusCode]: {
+    body: InferOrUndefined<NonNullable<AR[SC]>["body"]>;
+    headers: InferOrUndefined<NonNullable<AR[SC]>["headers"]>;
+  };
 };
 
 /**