diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index c4962599a..82edb9272 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -33,6 +33,15 @@ jobs:
         run: yarn
       - name: build
         run: yarn build
+      - name: lint
+        # not all packages pass linting yet - ongoing work
+        run: |
+          yarn workspace @orval/angular lint
+          yarn workspace @orval/axios lint
+          yarn workspace @orval/fetch lint
+          yarn workspace @orval/hono lint
+          yarn workspace @orval/mcp lint
+          yarn workspace @orval/swr lint
       - name: samples up to date
         uses: nickcharlton/diff-check@v1.0.0
         with:
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 6a50a5ed5..e20278b24 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,11 +1,14 @@
 {
   "cSpell.words": [
+    "axios",
     "Emptyish",
+    "hono",
     "listitem",
     "openapi",
     "Orval",
     "Petstore",
-    "tanstack"
+    "tanstack",
+    "zods"
   ],
   "files.associations": {
     "turbo.json": "jsonc"
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 4f24fb04e..d2d5bbbdd 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -37,9 +37,28 @@ export default defineConfig(
       'no-case-declarations': 'warn',
       'no-prototype-builtins': 'warn',
       'unicorn/prevent-abbreviations': 'off',
+      'unicorn/consistent-function-scoping': [
+        'error',
+        { checkArrowFunctions: false },
+      ],
+      '@typescript-eslint/restrict-template-expressions': [
+        'error',
+        // default (not strict) settings
+        // consider tightening these in the future
+        {
+          allow: [{ name: ['Error', 'URL', 'URLSearchParams'], from: 'lib' }],
+          allowAny: true,
+          allowBoolean: true,
+          allowNullish: true,
+          allowNumber: true,
+          allowRegExp: true,
+        },
+      ],
 
       // enable these in the future
+      'unicorn/no-null': 'warn',
       'unicorn/prefer-at': 'off',
+      'unicorn/no-array-reduce': 'warn',
       '@typescript-eslint/no-unused-vars': 'warn',
       '@typescript-eslint/ban-ts-comment': 'warn',
       '@typescript-eslint/no-explicit-any': 'warn',
diff --git a/packages/angular/src/index.ts b/packages/angular/src/index.ts
index 9f151ff91..141973379 100644
--- a/packages/angular/src/index.ts
+++ b/packages/angular/src/index.ts
@@ -118,6 +118,9 @@ export const generateAngularFooter: ClientFooterBuilder = ({
 
   for (const operationName of operationNames) {
     if (returnTypesToWrite.has(operationName)) {
+      // Map.has ensures Map.get will not return undefined, but TS still complains
+      // bug https://github.com/microsoft/TypeScript/issues/13086
+      // eslint-disable-next-line @typescript-eslint/restrict-plus-operands
       footer += returnTypesToWrite.get(operationName) + '\n';
     }
   }
@@ -142,9 +145,9 @@ const generateImplementation = (
   }: GeneratorVerbOptions,
   { route, context }: GeneratorOptions,
 ) => {
-  const isRequestOptions = override?.requestOptions !== false;
-  const isFormData = !override?.formData.disabled;
-  const isFormUrlEncoded = override?.formUrlEncoded !== false;
+  const isRequestOptions = override.requestOptions !== false;
+  const isFormData = !override.formData.disabled;
+  const isFormUrlEncoded = override.formUrlEncoded !== false;
   const isExactOptionalPropertyTypes =
     !!context.output.tsconfig?.compilerOptions?.exactOptionalPropertyTypes;
   const bodyForm = generateFormDataAndUrlEncodedFunction({
@@ -180,7 +183,7 @@ const generateImplementation = (
 
     const requestOptions = isRequestOptions
       ? generateMutatorRequestOptions(
-          override?.requestOptions,
+          override.requestOptions,
           mutator.hasThirdArg,
         )
       : '';
@@ -213,11 +216,11 @@ const generateImplementation = (
     queryParams,
     response,
     verb,
-    requestOptions: override?.requestOptions,
+    requestOptions: override.requestOptions,
     isFormData,
     isFormUrlEncoded,
     paramsSerializer,
-    paramsSerializerOptions: override?.paramsSerializerOptions,
+    paramsSerializerOptions: override.paramsSerializerOptions,
     isAngular: true,
     isExactOptionalPropertyTypes,
     hasSignal: false,
diff --git a/packages/axios/src/index.ts b/packages/axios/src/index.ts
index 36f063cb8..47e9f0103 100644
--- a/packages/axios/src/index.ts
+++ b/packages/axios/src/index.ts
@@ -76,9 +76,9 @@ const generateAxiosImplementation = (
   }: GeneratorVerbOptions,
   { route, context }: GeneratorOptions,
 ) => {
-  const isRequestOptions = override?.requestOptions !== false;
-  const isFormData = !override?.formData.disabled;
-  const isFormUrlEncoded = override?.formUrlEncoded !== false;
+  const isRequestOptions = override.requestOptions !== false;
+  const isFormData = !override.formData.disabled;
+  const isFormUrlEncoded = override.formUrlEncoded !== false;
   const isExactOptionalPropertyTypes =
     !!context.output.tsconfig?.compilerOptions?.exactOptionalPropertyTypes;
 
@@ -110,7 +110,7 @@ const generateAxiosImplementation = (
 
     const requestOptions = isRequestOptions
       ? generateMutatorRequestOptions(
-          override?.requestOptions,
+          override.requestOptions,
           mutator.hasSecondArg,
         )
       : '';
@@ -154,11 +154,11 @@ const generateAxiosImplementation = (
     queryParams,
     response,
     verb,
-    requestOptions: override?.requestOptions,
+    requestOptions: override.requestOptions,
     isFormData,
     isFormUrlEncoded,
     paramsSerializer,
-    paramsSerializerOptions: override?.paramsSerializerOptions,
+    paramsSerializerOptions: override.paramsSerializerOptions,
     isExactOptionalPropertyTypes,
     hasSignal: false,
   });
@@ -222,6 +222,9 @@ export const generateAxiosFooter: ClientFooterBuilder = ({
 
   for (const operationName of operationNames) {
     if (returnTypesToWrite.has(operationName)) {
+      // Map.has ensures Map.get will not return undefined, but TS still complains
+      // bug https://github.com/microsoft/TypeScript/issues/13086
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
       const func = returnTypesToWrite.get(operationName)!;
       footer += func(noFunction ? undefined : title) + '\n';
     }
@@ -240,10 +243,7 @@ export const generateAxios = (
   return { implementation, imports };
 };
 
-export const generateAxiosFunctions: ClientBuilder = async (
-  verbOptions,
-  options,
-) => {
+export const generateAxiosFunctions: ClientBuilder = (verbOptions, options) => {
   const { implementation, imports } = generateAxios(verbOptions, options);
 
   return {
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index 120940288..9d34dd116 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -38,7 +38,7 @@ export interface NormalizedOptions {
 
 export type NormalizedOutputOptions = {
   workspace?: string;
-  target?: string;
+  target: string;
   schemas?: string;
   namingConvention: NamingConvention;
   fileExtension: string;
@@ -71,8 +71,8 @@ export type NormalizedOverrideOutput = {
   title?: (title: string) => string;
   transformer?: OutputTransformer;
   mutator?: NormalizedMutator;
-  operations: Record<string, NormalizedOperationOptions>;
-  tags: Record<string, NormalizedOperationOptions>;
+  operations: Record<string, NormalizedOperationOptions | undefined>;
+  tags: Record<string, NormalizedOperationOptions | undefined>;
   mock?: OverrideMockOptions;
   contentType?: OverrideOutputContentType;
   header: false | ((info: InfoObject) => string[] | string);
@@ -208,7 +208,7 @@ export type EnumGeneration =
 
 export type OutputOptions = {
   workspace?: string;
-  target?: string;
+  target: string;
   schemas?: string;
   namingConvention?: NamingConvention;
   fileExtension?: string;
@@ -546,7 +546,7 @@ export type NormalizedZodOptions = {
     body: boolean | ZodCoerceType[];
     response: boolean | ZodCoerceType[];
   };
-  preprocess: {
+  preprocess?: {
     param?: NormalizedMutator;
     query?: NormalizedMutator;
     header?: NormalizedMutator;
@@ -616,9 +616,9 @@ export type AngularOptions = {
 export type SwrOptions = {
   useInfinite?: boolean;
   useSWRMutationForGet?: boolean;
-  swrOptions?: any;
-  swrMutationOptions?: any;
-  swrInfiniteOptions?: any;
+  swrOptions?: unknown;
+  swrMutationOptions?: unknown;
+  swrInfiniteOptions?: unknown;
 };
 
 export type NormalizedFetchOptions = {
diff --git a/packages/core/src/utils/get-property-safe.ts b/packages/core/src/utils/get-property-safe.ts
new file mode 100644
index 000000000..a03dc66c5
--- /dev/null
+++ b/packages/core/src/utils/get-property-safe.ts
@@ -0,0 +1,22 @@
+/**
+ * Type safe way to get arbitrary property from an object.
+ *
+ * @param obj - The object from which to retrieve the property.
+ * @param propertyName - The name of the property to retrieve.
+ * @returns Object with `hasProperty: true` and `value` of the property if it exists; otherwise `hasProperty: false` and undefined.
+ *
+ * @remarks Until TypeScript adds type-narrowing for Object.hasOwn we have to use this workaround
+ */
+export function getPropertySafe<T extends object, K extends keyof T>(
+  obj: T,
+  propertyName: K | string,
+):
+  | { hasProperty: true; value: T[K] }
+  | { hasProperty: false; value: undefined } {
+  if (Object.hasOwn(obj, propertyName)) {
+    // safe to cast here because of the above check
+    return { hasProperty: true, value: obj[propertyName as K] };
+  }
+
+  return { hasProperty: false, value: undefined };
+}
diff --git a/packages/core/src/utils/index.ts b/packages/core/src/utils/index.ts
index 8c1d25c51..a2afb4b97 100644
--- a/packages/core/src/utils/index.ts
+++ b/packages/core/src/utils/index.ts
@@ -9,6 +9,7 @@ export * from './dynamic-import';
 export * from './extension';
 export * from './file';
 export * from './file-extensions';
+export * from './get-property-safe';
 export * from './is-body-verb';
 export * from './logger';
 export * from './merge-deep';
diff --git a/packages/fetch/src/index.ts b/packages/fetch/src/index.ts
index 1384ae728..d147e0433 100644
--- a/packages/fetch/src/index.ts
+++ b/packages/fetch/src/index.ts
@@ -39,9 +39,9 @@ export const generateRequestFunction = (
   }: GeneratorVerbOptions,
   { route, context, pathRoute }: GeneratorOptions,
 ) => {
-  const isRequestOptions = override?.requestOptions !== false;
-  const isFormData = !override?.formData.disabled;
-  const isFormUrlEncoded = override?.formUrlEncoded !== false;
+  const isRequestOptions = override.requestOptions !== false;
+  const isFormData = !override.formData.disabled;
+  const isFormUrlEncoded = override.formUrlEncoded !== false;
 
   const getUrlFnName = camel(`get-${operationName}-url`);
   const getUrlFnProps = toObjectString(
@@ -58,7 +58,7 @@ export const generateRequestFunction = (
     | PathItemObject
     | undefined;
   const parameters =
-    spec?.[verb]?.parameters || ([] as (ParameterObject | ReferenceObject)[]);
+    spec?.[verb]?.parameters ?? ([] as (ParameterObject | ReferenceObject)[]);
 
   const explodeParameters = parameters.filter((parameter) => {
     const { schema } = resolveRef<ParameterObject>(parameter, context);
@@ -129,9 +129,11 @@ ${
     contentType === 'application/nd-json' ||
     contentType === 'application/x-ndjson';
 
-  const isNdJson = response.contentTypes.some(isContentTypeNdJson);
+  const isNdJson = response.contentTypes.some((contentType) =>
+    isContentTypeNdJson(contentType),
+  );
   const responseTypeName = fetchResponseTypeName(
-    override.fetch?.includeHttpResponseReturnType,
+    override.fetch.includeHttpResponseReturnType,
     isNdJson ? 'Response' : response.definition.success,
     operationName,
   );
@@ -230,8 +232,8 @@ ${override.fetch.forceSuccessResponse && hasSuccess ? '' : `export type ${respon
       ? `Promise<${successName}>`
       : `Promise<${responseTypeName}>`;
 
-  const globalFetchOptions = isObject(override?.requestOptions)
-    ? `${stringify(override?.requestOptions)?.slice(1, -1)?.trim()}`
+  const globalFetchOptions = isObject(override.requestOptions)
+    ? stringify(override.requestOptions)?.slice(1, -1).trim()
     : '';
   const fetchMethodOption = `method: '${verb.toUpperCase()}'`;
   const ignoreContentTypes = ['multipart/form-data'];
diff --git a/packages/hono/src/index.ts b/packages/hono/src/index.ts
index 53c9f71e7..6ceaf4fb2 100644
--- a/packages/hono/src/index.ts
+++ b/packages/hono/src/index.ts
@@ -9,7 +9,6 @@ import {
   generateMutatorImports,
   type GeneratorDependency,
   type GeneratorImport,
-  type GeneratorMutator,
   type GeneratorVerbOptions,
   getFileInfo,
   getOrvalGeneratedTypes,
@@ -176,48 +175,49 @@ const getHonoHandlers = (
   handlerCode: string,
   /** Whether any of the handler code snippets requires importing zValidator. */
   hasZValidator: boolean,
-] =>
-  opts.reduce<[string, boolean]>(
-    ([code, hasZValidator], opts) => {
-      const { handlerName, contextTypeName, verbOption, validator } = opts;
+] => {
+  let code = '';
+  let hasZValidator = false;
 
-      let currentValidator = '';
+  for (const { handlerName, contextTypeName, verbOption, validator } of opts) {
+    let currentValidator = '';
 
-      if (validator) {
-        if (verbOption.headers) {
-          currentValidator += `zValidator('header', ${verbOption.operationName}Header),\n`;
-        }
-        if (verbOption.params.length > 0) {
-          currentValidator += `zValidator('param', ${verbOption.operationName}Params),\n`;
-        }
-        if (verbOption.queryParams) {
-          currentValidator += `zValidator('query', ${verbOption.operationName}QueryParams),\n`;
-        }
-        if (verbOption.body.definition) {
-          currentValidator += `zValidator('json', ${verbOption.operationName}Body),\n`;
-        }
-        if (
-          validator !== 'hono' &&
-          verbOption.response.originalSchema?.['200']?.content?.[
-            'application/json'
-          ]
-        ) {
-          currentValidator += `zValidator('response', ${verbOption.operationName}Response),\n`;
-        }
+    if (validator) {
+      if (verbOption.headers) {
+        currentValidator += `zValidator('header', ${verbOption.operationName}Header),\n`;
+      }
+      if (verbOption.params.length > 0) {
+        currentValidator += `zValidator('param', ${verbOption.operationName}Params),\n`;
       }
+      if (verbOption.queryParams) {
+        currentValidator += `zValidator('query', ${verbOption.operationName}QueryParams),\n`;
+      }
+      if (verbOption.body.definition) {
+        currentValidator += `zValidator('json', ${verbOption.operationName}Body),\n`;
+      }
+      if (
+        validator !== 'hono' &&
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+        verbOption.response.originalSchema?.['200']?.content?.[
+          'application/json'
+        ]
+      ) {
+        currentValidator += `zValidator('response', ${verbOption.operationName}Response),\n`;
+      }
+    }
 
-      code += `
+    code += `
 export const ${handlerName} = factory.createHandlers(
 ${currentValidator}async (c: ${contextTypeName}) => {
 
   },
 );`;
-      hasZValidator ||= currentValidator !== '';
 
-      return [code, hasZValidator];
-    },
-    ['', false],
-  );
+    hasZValidator ||= currentValidator !== '';
+  }
+
+  return [code, hasZValidator];
+};
 
 const getZvalidatorImports = (
   verbOptions: GeneratorVerbOptions[],
@@ -252,6 +252,7 @@ const getZvalidatorImports = (
 
     if (
       !isHonoValidator &&
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
       response.originalSchema?.['200']?.content?.['application/json'] !=
         undefined
     ) {
@@ -267,16 +268,20 @@ const getZvalidatorImports = (
 const getVerbOptionGroupByTag = (
   verbOptions: Record<string, GeneratorVerbOptions>,
 ) => {
-  return Object.values(verbOptions).reduce<
-    Record<string, GeneratorVerbOptions[]>
-  >((acc, value) => {
+  const grouped: Record<string, GeneratorVerbOptions[]> = {};
+
+  for (const value of Object.values(verbOptions)) {
     const tag = value.tags[0];
-    if (!acc[tag]) {
-      acc[tag] = [];
+    // this is not always false
+    // TODO look into types
+    // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+    if (!grouped[tag]) {
+      grouped[tag] = [];
     }
-    acc[tag].push(value);
-    return acc;
-  }, {});
+    grouped[tag].push(value);
+  }
+
+  return grouped;
 };
 
 const generateHandlerFile = async ({
@@ -303,21 +308,19 @@ const generateHandlerFile = async ({
     const rawFile = await fs.readFile(path, 'utf8');
     let content = rawFile;
 
-    content += Object.values(verbs).reduce((acc, verbOption) => {
+    for (const verbOption of Object.values(verbs)) {
       const handlerName = `${verbOption.operationName}Handlers`;
       const contextTypeName = `${pascal(verbOption.operationName)}Context`;
 
       if (!rawFile.includes(handlerName)) {
-        acc += getHonoHandlers({
+        content += getHonoHandlers({
           handlerName,
           contextTypeName,
           verbOption,
           validator,
         })[0];
       }
-
-      return acc;
-    }, '');
+    }
 
     return content;
   }
@@ -469,7 +472,7 @@ const getContext = (verbOption: GeneratorVerbOptions) => {
   }
 
   const queryType = verbOption.queryParams
-    ? `query: ${verbOption.queryParams?.schema.name},`
+    ? `query: ${verbOption.queryParams.schema.name},`
     : '';
   const bodyType = verbOption.body.definition
     ? `json: ${verbOption.body.definition},`
@@ -617,7 +620,7 @@ const generateZodFiles = async (
     const builderContexts = await Promise.all(
       Object.entries(groupByTags).map(async ([tag, verbs]) => {
         const zods = await Promise.all(
-          verbs.map((verbOption) =>
+          verbs.map(async (verbOption) =>
             generateZod(
               verbOption,
               {
@@ -626,7 +629,7 @@ const generateZodFiles = async (
                 override: output.override,
                 context,
                 mock: output.mock,
-                output: output.target!,
+                output: output.target,
               },
               output.client,
             ),
@@ -640,18 +643,14 @@ const generateZodFiles = async (
           };
         }
 
-        const allMutators = zods.reduce<Record<string, GeneratorMutator>>(
-          (acc, z) => {
-            for (const mutator of z.mutators ?? []) {
-              acc[mutator.name] = mutator;
-            }
-            return acc;
-          },
-          {},
-        );
+        const allMutators = new Map(
+          zods.flatMap((z) => z.mutators ?? []).map((m) => [m.name, m]),
+        )
+          .values()
+          .toArray();
 
         const mutatorsImports = generateMutatorImports({
-          mutators: Object.values(allMutators),
+          mutators: allMutators,
         });
 
         let content = `${header}import { z as zod } from 'zod';\n${mutatorsImports}\n`;
@@ -670,13 +669,11 @@ const generateZodFiles = async (
       }),
     );
 
-    return Promise.all(
-      builderContexts.filter((context) => context.content !== ''),
-    );
+    return builderContexts.filter((context) => context.content !== '');
   }
 
   const zods = await Promise.all(
-    Object.values(verbOptions).map((verbOption) =>
+    Object.values(verbOptions).map(async (verbOption) =>
       generateZod(
         verbOption,
         {
@@ -685,25 +682,21 @@ const generateZodFiles = async (
           override: output.override,
           context,
           mock: output.mock,
-          output: output.target!,
+          output: output.target,
         },
         output.client,
       ),
     ),
   );
 
-  const allMutators = zods.reduce<Record<string, GeneratorMutator>>(
-    (acc, z) => {
-      for (const mutator of z.mutators ?? []) {
-        acc[mutator.name] = mutator;
-      }
-      return acc;
-    },
-    {},
-  );
+  const allMutators = new Map(
+    zods.flatMap((z) => z.mutators ?? []).map((m) => [m.name, m]),
+  )
+    .values()
+    .toArray();
 
   const mutatorsImports = generateMutatorImports({
-    mutators: Object.values(allMutators),
+    mutators: allMutators,
   });
 
   let content = `${header}import { z as zod } from 'zod';\n${mutatorsImports}\n`;
@@ -742,7 +735,7 @@ const generateZvalidator = (
   };
 };
 
-const generateCompositeRoutes = async (
+const generateCompositeRoutes = (
   verbOptions: Record<string, GeneratorVerbOptions>,
   output: NormalizedOutputOptions,
   context: ContextSpecs,
@@ -776,7 +769,7 @@ const generateCompositeRoutes = async (
 
         const handlersPath = generateModuleSpecifier(
           compositeRouteInfo.path,
-          upath.join(handlerFileInfo.dirname ?? '', `./${operationName}`),
+          upath.join(handlerFileInfo.dirname, `./${operationName}`),
         );
 
         return `import { ${importHandlerName} } from '${handlersPath}';`;
@@ -797,7 +790,7 @@ const generateCompositeRoutes = async (
 
         const handlersPath = generateModuleSpecifier(
           compositeRouteInfo.path,
-          upath.join(targetInfo.dirname ?? '', tag),
+          upath.join(targetInfo.dirname, tag),
         );
 
         return `import {\n${importHandlerNames}\n} from '${handlersPath}/${tag}.handlers';`;
@@ -841,13 +834,18 @@ export const generateExtraFiles: ClientExtraFilesBuilder = async (
     schemaModule = `${pathWithoutExtension}.schemas`;
   }
 
-  const [handlers, contexts, zods, compositeRoutes] = await Promise.all([
+  const contexts = generateContextFiles(
+    verbOptions,
+    output,
+    context,
+    schemaModule,
+  );
+  const compositeRoutes = output.override.hono.compositeRoute
+    ? generateCompositeRoutes(verbOptions, output, context)
+    : [];
+  const [handlers, zods] = await Promise.all([
     generateHandlerFiles(verbOptions, output, validator.path),
-    generateContextFiles(verbOptions, output, context, schemaModule),
     generateZodFiles(verbOptions, output, context),
-    output.override.hono.compositeRoute
-      ? generateCompositeRoutes(verbOptions, output, context)
-      : [],
   ]);
 
   return [
diff --git a/packages/hono/src/route.ts b/packages/hono/src/route.ts
index bf80e4df9..1c5599761 100644
--- a/packages/hono/src/route.ts
+++ b/packages/hono/src/route.ts
@@ -15,21 +15,18 @@ const getRoutePath = (path: string): string => {
   });
   const next = hasParam(matches[3]) ? getRoutePath(matches[3]) : matches[3];
 
-  return hasParam(path) ? `${prev}\:${param}${next}` : `${prev}${param}${next}`;
+  return hasParam(path) ? `${prev}:${param}${next}` : `${prev}${param}${next}`;
 };
 
 export const getRoute = (route: string) => {
   const splittedRoute = route.split('/');
 
-  return splittedRoute.reduce((acc, path, i) => {
-    if (!path && !i) {
-      return acc;
-    }
+  let acc = '';
+  for (const [i, path] of splittedRoute.entries()) {
+    if (!path && i === 0) continue;
 
-    if (!path.includes('{')) {
-      return `${acc}/${path}`;
-    }
+    acc += path.includes('{') ? `/${getRoutePath(path)}` : `/${path}`;
+  }
 
-    return `${acc}/${getRoutePath(path)}`;
-  }, '');
+  return acc;
 };
diff --git a/packages/mcp/src/index.ts b/packages/mcp/src/index.ts
index 8ff0b71ce..27d8cb403 100644
--- a/packages/mcp/src/index.ts
+++ b/packages/mcp/src/index.ts
@@ -6,7 +6,6 @@ import {
   type ClientHeaderBuilder,
   type ContextSpecs,
   generateMutatorImports,
-  type GeneratorMutator,
   type GeneratorVerbOptions,
   getFileInfo,
   getFullRoute,
@@ -32,11 +31,7 @@ const getHeader = (
   return Array.isArray(header) ? jsDoc({ description: header }) : header;
 };
 
-export const getMcpHeader: ClientHeaderBuilder = ({
-  verbOptions,
-  output,
-  clientImplementation,
-}) => {
+export const getMcpHeader: ClientHeaderBuilder = ({ verbOptions, output }) => {
   const targetInfo = getFileInfo(output.target);
   const schemaInfo = getFileInfo(output.schemas);
 
@@ -44,8 +39,8 @@ export const getMcpHeader: ClientHeaderBuilder = ({
     ? upath.relativeSafe(targetInfo.dirname, schemaInfo.dirname)
     : './' + targetInfo.filename + '.schemas';
 
-  const importSchemaNames = Object.values(verbOptions)
-    .flatMap((verbOption) => {
+  const importSchemaNames = new Set(
+    Object.values(verbOptions).flatMap((verbOption) => {
       const imports = [];
       const pascalOperationName = pascal(verbOption.operationName);
 
@@ -58,13 +53,10 @@ export const getMcpHeader: ClientHeaderBuilder = ({
       }
 
       return imports;
-    })
-    .reduce<string[]>((acc, name) => {
-      if (!acc.find((i) => i === name)) {
-        acc.push(name);
-      }
-      return acc;
-    }, []);
+    }),
+  )
+    .values()
+    .toArray();
 
   const importSchemasImplementation = `import {\n  ${importSchemaNames.join(
     ',\n  ',
@@ -72,15 +64,13 @@ export const getMcpHeader: ClientHeaderBuilder = ({
 `;
 
   const relativeFetchClientPath = './http-client';
-  const importFetchClientNames = Object.values(verbOptions)
-    .flatMap((verbOption) => verbOption.operationName)
-    .reduce<string[]>((acc, name) => {
-      if (!acc.find((i) => i === name)) {
-        acc.push(name);
-      }
-
-      return acc;
-    }, []);
+  const importFetchClientNames = new Set(
+    Object.values(verbOptions).flatMap(
+      (verbOption) => verbOption.operationName,
+    ),
+  )
+    .values()
+    .toArray();
 
   const importFetchClientImplementation = `import {\n  ${importFetchClientNames.join(
     ',\n  ',
@@ -95,7 +85,7 @@ export const getMcpHeader: ClientHeaderBuilder = ({
   return content + '\n';
 };
 
-export const generateMcp: ClientBuilder = async (verbOptions, options) => {
+export const generateMcp: ClientBuilder = (verbOptions) => {
   const handlerArgsTypes = [];
   const pathParamsType = verbOptions.params
     .map((param) => {
@@ -167,7 +157,7 @@ export const ${handlerName} = async (${handlerArgsTypes.length > 0 ? `args: ${ha
   };
 };
 
-export const generateServer = async (
+export const generateServer = (
   verbOptions: Record<string, GeneratorVerbOptions>,
   output: NormalizedOutputOptions,
   context: ContextSpecs,
@@ -179,29 +169,29 @@ export const generateServer = async (
 
   const toolImplementations = Object.values(verbOptions)
     .map((verbOption) => {
-      const imputSchemaTypes = [];
+      const inputSchemaTypes = [];
       if (verbOption.params.length > 0)
-        imputSchemaTypes.push(
+        inputSchemaTypes.push(
           `  pathParams: ${verbOption.operationName}Params`,
         );
       if (verbOption.queryParams)
-        imputSchemaTypes.push(
+        inputSchemaTypes.push(
           `  queryParams: ${verbOption.operationName}QueryParams`,
         );
       if (verbOption.body.definition)
-        imputSchemaTypes.push(`  bodyParams: ${verbOption.operationName}Body`);
+        inputSchemaTypes.push(`  bodyParams: ${verbOption.operationName}Body`);
 
-      const imputSchemaImplementation =
-        imputSchemaTypes.length > 0
+      const inputSchemaImplementation =
+        inputSchemaTypes.length > 0
           ? `  {
-  ${imputSchemaTypes.join(',\n  ')}
+  ${inputSchemaTypes.join(',\n  ')}
   },`
           : '';
 
       const toolImplementation = `
 server.tool(
   '${verbOption.operationName}',
-  '${verbOption.summary}',${imputSchemaImplementation ? `\n${imputSchemaImplementation}` : ''}
+  '${verbOption.summary}',${inputSchemaImplementation ? `\n${inputSchemaImplementation}` : ''}
   ${verbOption.operationName}Handler
 );`;
 
@@ -280,7 +270,7 @@ const generateZodFiles = async (
   output: NormalizedOutputOptions,
   context: ContextSpecs,
 ) => {
-  const { extension, dirname, filename } = getFileInfo(output.target);
+  const { extension, dirname } = getFileInfo(output.target);
 
   const header = getHeader(
     output.override.header,
@@ -288,7 +278,7 @@ const generateZodFiles = async (
   );
 
   const zods = await Promise.all(
-    Object.values(verbOptions).map((verbOption) =>
+    Object.values(verbOptions).map(async (verbOption) =>
       generateZod(
         verbOption,
         {
@@ -297,25 +287,21 @@ const generateZodFiles = async (
           override: output.override,
           context,
           mock: output.mock,
-          output: output.target!,
+          output: output.target,
         },
         output.client,
       ),
     ),
   );
 
-  const allMutators = zods.reduce<Record<string, GeneratorMutator>>(
-    (acc, z) => {
-      for (const mutator of z.mutators ?? []) {
-        acc[mutator.name] = mutator;
-      }
-      return acc;
-    },
-    {},
-  );
+  const allMutators = new Map(
+    zods.flatMap((z) => z.mutators ?? []).map((m) => [m.name, m]),
+  )
+    .values()
+    .toArray();
 
   const mutatorsImports = generateMutatorImports({
-    mutators: Object.values(allMutators),
+    mutators: allMutators,
   });
 
   let content = `${header}import { z as zod } from 'zod';\n${mutatorsImports}\n`;
@@ -332,7 +318,7 @@ const generateZodFiles = async (
   ];
 };
 
-const generateHttpClinetFiles = async (
+const generateHttpClientFiles = async (
   verbOptions: Record<string, GeneratorVerbOptions>,
   output: NormalizedOutputOptions,
   context: ContextSpecs,
@@ -345,7 +331,7 @@ const generateHttpClinetFiles = async (
   );
 
   const clients = await Promise.all(
-    Object.values(verbOptions).map((verbOption) => {
+    Object.values(verbOptions).map(async (verbOption) => {
       const fullRoute = getFullRoute(
         verbOption.route,
         context.specs[context.specKey].servers,
@@ -358,7 +344,7 @@ const generateHttpClinetFiles = async (
         override: output.override,
         context,
         mock: output.mock,
-        output: output.target!,
+        output: output.target,
       };
 
       return generateClient(verbOption, options, output.client, output);
@@ -372,16 +358,13 @@ const generateHttpClinetFiles = async (
   const relativeSchemasPath = output.schemas
     ? upath.relativeSafe(dirname, getFileInfo(output.schemas).dirname)
     : './' + filename + '.schemas';
+
   const importNames = clients
     .flatMap((client) => client.imports)
-    .reduce<string[]>((acc, imp) => {
-      if (!acc.find((i) => i === imp.name)) {
-        acc.push(imp.name);
-      }
+    .map((imp) => imp.name);
+  const uniqueImportNames = new Set(importNames).values().toArray();
 
-      return acc;
-    }, []);
-  const importImplementation = `import { ${importNames.join(
+  const importImplementation = `import { ${uniqueImportNames.join(
     ',\n',
   )} } from '${relativeSchemasPath}';`;
 
@@ -419,10 +402,10 @@ export const generateExtraFiles: ClientExtraFilesBuilder = async (
   output,
   context,
 ) => {
-  const [server, zods, httpClients] = await Promise.all([
-    generateServer(verbOptions, output, context),
+  const server = generateServer(verbOptions, output, context);
+  const [zods, httpClients] = await Promise.all([
     generateZodFiles(verbOptions, output, context),
-    generateHttpClinetFiles(verbOptions, output, context),
+    generateHttpClientFiles(verbOptions, output, context),
   ]);
 
   return [...server, ...zods, ...httpClients];
diff --git a/packages/mock/src/delay.ts b/packages/mock/src/delay.ts
index a6e2e08ad..a2b6f44e1 100644
--- a/packages/mock/src/delay.ts
+++ b/packages/mock/src/delay.ts
@@ -4,10 +4,7 @@ export const getDelay = (
   override?: NormalizedOverrideOutput,
   options?: GlobalMockOptions,
 ): GlobalMockOptions['delay'] => {
-  const overrideDelay =
-    override?.mock?.delay === undefined
-      ? options?.delay
-      : override?.mock?.delay;
+  const overrideDelay = override?.mock?.delay ?? options?.delay;
   const delayFunctionLazyExecute =
     override?.mock?.delayFunctionLazyExecute ??
     options?.delayFunctionLazyExecute;
diff --git a/packages/mock/src/faker/compatibleV9.test.ts b/packages/mock/src/faker/compatible-v9.test.ts
similarity index 95%
rename from packages/mock/src/faker/compatibleV9.test.ts
rename to packages/mock/src/faker/compatible-v9.test.ts
index 525336c53..808f0029d 100644
--- a/packages/mock/src/faker/compatibleV9.test.ts
+++ b/packages/mock/src/faker/compatible-v9.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest';
 
-import { isFakerVersionV9 } from './compatibleV9';
+import { isFakerVersionV9 } from './compatible-v9';
 
 describe('isFakerVersionV9', () => {
   it('should return false when faker is not in package.json', () => {
diff --git a/packages/mock/src/faker/compatibleV9.ts b/packages/mock/src/faker/compatible-v9.ts
similarity index 100%
rename from packages/mock/src/faker/compatibleV9.ts
rename to packages/mock/src/faker/compatible-v9.ts
diff --git a/packages/mock/src/faker/getters/combine.ts b/packages/mock/src/faker/getters/combine.ts
index 6067050fc..8041b5281 100644
--- a/packages/mock/src/faker/getters/combine.ts
+++ b/packages/mock/src/faker/getters/combine.ts
@@ -73,7 +73,7 @@ export const combineSchemasMock = ({
       if (
         '$ref' in val &&
         existingReferencedProperties.includes(
-          pascal(val.$ref.split('/').pop()!),
+          pascal(val.$ref.split('/').pop() ?? ''),
         )
       ) {
         if (arr.length === 1) {
@@ -96,7 +96,7 @@ export const combineSchemasMock = ({
         schema: {
           ...val,
           name: item.name,
-          path: item.path ? item.path : '#',
+          path: item.path ?? '#',
         },
         combine: {
           separator,
@@ -139,7 +139,9 @@ export const combineSchemasMock = ({
   let finalValue =
     value === 'undefined'
       ? value
-      : `${separator === 'allOf' && !containsOnlyPrimitiveValues ? '{' : ''}${value}${separator === 'allOf' ? (containsOnlyPrimitiveValues ? '' : '}') : '])'}`;
+      : // containsOnlyPrimitiveValues isn't just true, it's being set to false inside the above reduce and the type system doesn't detect it
+        // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+        `${separator === 'allOf' && !containsOnlyPrimitiveValues ? '{' : ''}${value}${separator === 'allOf' ? (containsOnlyPrimitiveValues ? '' : '}') : '])'}`;
   if (itemResolvedValue) {
     finalValue = finalValue.startsWith('...')
       ? `...{${finalValue}, ${itemResolvedValue.value}}`
diff --git a/packages/mock/src/faker/getters/object.ts b/packages/mock/src/faker/getters/object.ts
index a7a8c32e7..c246e575c 100644
--- a/packages/mock/src/faker/getters/object.ts
+++ b/packages/mock/src/faker/getters/object.ts
@@ -99,9 +99,7 @@ export const getMockObject = ({
 
   if (item.properties) {
     let value =
-      !combine ||
-      combine?.separator === 'oneOf' ||
-      combine?.separator === 'anyOf'
+      !combine || combine.separator === 'oneOf' || combine.separator === 'anyOf'
         ? '{'
         : '';
     const imports: GeneratorImport[] = [];
@@ -120,7 +118,7 @@ export const getMockObject = ({
         }
 
         const isRequired =
-          mockOptions?.required ||
+          mockOptions?.required ??
           (Array.isArray(item.required) ? item.required : []).includes(key);
 
         // Check to see if the property is a reference to an existing property
@@ -128,7 +126,7 @@ export const getMockObject = ({
         if (
           '$ref' in prop &&
           existingReferencedProperties.includes(
-            pascal(prop.$ref.split('/').pop()!),
+            pascal(prop.$ref.split('/').pop() ?? ''),
           )
         ) {
           return;
@@ -167,9 +165,7 @@ export const getMockObject = ({
 
     value += properyScalars.join(', ');
     value +=
-      !combine ||
-      combine?.separator === 'oneOf' ||
-      combine?.separator === 'anyOf'
+      !combine || combine.separator === 'oneOf' || combine.separator === 'anyOf'
         ? '}'
         : '';
 
@@ -188,7 +184,7 @@ export const getMockObject = ({
     if (
       isReference(item.additionalProperties) &&
       existingReferencedProperties.includes(
-        item.additionalProperties.$ref.split('/').pop()!,
+        item.additionalProperties.$ref.split('/').pop() ?? '',
       )
     ) {
       return { value: `{}`, imports: [], name: item.name };
diff --git a/packages/mock/src/faker/getters/route.ts b/packages/mock/src/faker/getters/route.ts
index 6e07272ce..6a89ece7f 100644
--- a/packages/mock/src/faker/getters/route.ts
+++ b/packages/mock/src/faker/getters/route.ts
@@ -19,7 +19,7 @@ const getRoutePath = (path: string): string => {
 };
 
 export const getRouteMSW = (route: string, baseUrl = '*') => {
-  route = route.replaceAll(':', '\\\:');
+  route = route.replaceAll(':', String.raw`\:`);
   const splittedRoute = route.split('/');
 
   return splittedRoute.reduce((acc, path, i) => {
diff --git a/packages/mock/src/faker/getters/scalar.test.ts b/packages/mock/src/faker/getters/scalar.test.ts
index 53c185700..286e848cc 100644
--- a/packages/mock/src/faker/getters/scalar.test.ts
+++ b/packages/mock/src/faker/getters/scalar.test.ts
@@ -119,7 +119,7 @@ describe('getMockScalar (example handling with falsy values)', () => {
     existingReferencedProperties: [],
     splitMockImplementations: [],
     mockOptions: { useExamples: true },
-    context: { output: {} } as ContextSpecs,
+    context: { output: { override: {} } } as ContextSpecs, // TODO this should be: satisfies ContextSpecs
   };
 
   it('should return the example value when it is a false value', () => {
diff --git a/packages/mock/src/faker/getters/scalar.ts b/packages/mock/src/faker/getters/scalar.ts
index 024db4721..b9129a209 100644
--- a/packages/mock/src/faker/getters/scalar.ts
+++ b/packages/mock/src/faker/getters/scalar.ts
@@ -11,7 +11,7 @@ import {
 import type { SchemaObject as SchemaObject31 } from 'openapi3-ts/oas31';
 
 import type { MockDefinition, MockSchemaObject } from '../../types';
-import { isFakerVersionV9 } from '../compatibleV9';
+import { isFakerVersionV9 } from '../compatible-v9';
 import { DEFAULT_FORMAT_MOCK } from '../constants';
 import {
   getNullable,
@@ -65,7 +65,7 @@ export const getMockScalar = ({
   }
 
   const overrideTag = Object.entries(mockOptions?.tags ?? {})
-    .sort((a, b) => {
+    .toSorted((a, b) => {
       return a[0].localeCompare(b[0]);
     })
     .reduce(
@@ -74,7 +74,7 @@ export const getMockScalar = ({
       {} as { properties: Record<string, unknown> },
     );
 
-  const tagProperty = resolveMockOverride(overrideTag?.properties, item);
+  const tagProperty = resolveMockOverride(overrideTag.properties, item);
 
   if (tagProperty) {
     return tagProperty;
@@ -87,7 +87,7 @@ export const getMockScalar = ({
   }
 
   if (
-    (context.output.override?.mock?.useExamples || mockOptions?.useExamples) &&
+    (context.output.override.mock?.useExamples || mockOptions?.useExamples) &&
     item.example !== undefined
   ) {
     return {
@@ -152,8 +152,8 @@ export const getMockScalar = ({
           existingReferencedProperties,
           'number',
         );
-      } else if ('const' in item) {
-        value = '' + (item as SchemaObject31).const;
+      } else if ('const' in item && typeof item.const === 'string') {
+        value = item.const;
       }
 
       return {
@@ -166,8 +166,8 @@ export const getMockScalar = ({
 
     case 'boolean': {
       let value = 'faker.datatype.boolean()';
-      if ('const' in item) {
-        value = '' + (item as SchemaObject31).const;
+      if ('const' in item && typeof item.const === 'string') {
+        value = item.const;
       }
       return {
         value,
@@ -184,7 +184,7 @@ export const getMockScalar = ({
       if (
         '$ref' in item.items &&
         existingReferencedProperties.includes(
-          pascal(item.items.$ref.split('/').pop()!),
+          pascal(item.items.$ref.split('/').pop() ?? ''),
         )
       ) {
         return { value: '[]', imports: [], name: item.name };
@@ -334,8 +334,8 @@ const getEnum = (
   type?: 'string' | 'number',
 ) => {
   if (!item.enum) return '';
-  const joindEnumValues = item.enum
-    .filter((e) => e !== null)
+  const joinedEnumValues = item.enum
+    .filter((e) => e !== null) // TODO fix type, e can absolutely be null
     .map((e) =>
       type === 'string' || (type === undefined && typeof e === 'string')
         ? `'${escape(e)}'`
@@ -343,7 +343,7 @@ const getEnum = (
     )
     .join(',');
 
-  let enumValue = `[${joindEnumValues}]`;
+  let enumValue = `[${joinedEnumValues}]`;
   if (context.output.override.enumGenerationType === EnumGeneration.ENUM) {
     if (item.isRef || existingReferencedProperties.length === 0) {
       enumValue += ` as ${item.name}${item.name.endsWith('[]') ? '' : '[]'}`;
diff --git a/packages/mock/src/faker/resolvers/value.ts b/packages/mock/src/faker/resolvers/value.ts
index 13ba1855d..30ffb88ed 100644
--- a/packages/mock/src/faker/resolvers/value.ts
+++ b/packages/mock/src/faker/resolvers/value.ts
@@ -8,6 +8,7 @@ import {
   pascal,
 } from '@orval/core';
 import type { SchemaObject } from 'openapi3-ts/oas30';
+import { prop } from 'remeda';
 
 import type { MockDefinition, MockSchemaObject } from '../../types';
 import { overrideVarName } from '../getters';
@@ -19,7 +20,7 @@ export const resolveMockOverride = (
   properties: Record<string, unknown> | undefined = {},
   item: SchemaObject & { name: string; path?: string },
 ) => {
-  const path = item.path ? item.path : `#.${item.name}`;
+  const path = item.path ?? `#.${item.name}`;
   const property = Object.entries(properties).find(([key]) => {
     if (isRegex(key)) {
       const regex = new RegExp(key.slice(1, -1));
@@ -86,12 +87,10 @@ export const resolveMockValue = ({
     } = getRefInfo(schema.$ref, context);
 
     const schemaRef = Array.isArray(refPaths)
-      ? (refPaths.reduce(
-          (obj, key) =>
-            obj && typeof obj === 'object'
-              ? (obj as Record<string, any>)[key]
-              : undefined,
+      ? (prop(
           context.specs[specKey],
+          // @ts-expect-error: [ts2556] refPaths are not guaranteed to be valid keys of the spec
+          ...refPaths,
         ) as Partial<SchemaObject>)
       : undefined;
 
@@ -100,7 +99,7 @@ export const resolveMockValue = ({
       name: pascal(originalName),
       path: schema.path,
       isRef: true,
-      required: [...(schemaRef?.required ?? []), ...(schema?.required ?? [])],
+      required: [...(schemaRef?.required ?? []), ...(schema.required ?? [])],
     };
 
     const newSeparator = newSchema.allOf
@@ -138,7 +137,7 @@ export const resolveMockValue = ({
     ) {
       const funcName = `get${pascal(operationId)}Response${pascal(newSchema.name)}Mock`;
       if (
-        !splitMockImplementations?.some((f) =>
+        !splitMockImplementations.some((f) =>
           f.includes(`export const ${funcName}`),
         )
       ) {
@@ -151,7 +150,7 @@ export const resolveMockValue = ({
 
         const args = `${overrideVarName}: ${type} = {}`;
         const func = `export const ${funcName} = (${args}): ${newSchema.name} => ({${scalar.value.startsWith('...') ? '' : '...'}${scalar.value}, ...${overrideVarName}});`;
-        splitMockImplementations?.push(func);
+        splitMockImplementations.push(func);
       }
 
       scalar.value = newSchema.nullable
diff --git a/packages/mock/src/msw/index.ts b/packages/mock/src/msw/index.ts
index 9e71a8d48..5b19917e1 100644
--- a/packages/mock/src/msw/index.ts
+++ b/packages/mock/src/msw/index.ts
@@ -134,9 +134,7 @@ const generateDefinition = (
   const handlerImplementation = `
 export const ${handlerName} = (overrideResponse?: ${returnType} | ((${infoParam}: Parameters<Parameters<typeof http.${verb}>[1]>[0]) => Promise<${returnType}> | ${returnType}), options?: RequestHandlerOptions) => {
   return http.${verb}('${route}', async (${infoParam}) => {${
-    delay === false
-      ? ''
-      : `await delay(${isFunction(delay) ? `(${delay})()` : delay});`
+    typeof delay === 'number' ? `await delay(${delay});` : ''
   }
   ${isReturnHttpResponse ? '' : `if (typeof overrideResponse === 'function') {await overrideResponse(info); }`}
     return new HttpResponse(${
@@ -188,7 +186,7 @@ export const generateMSW = (
 
   const route = getRouteMSW(
     pathRoute,
-    override?.mock?.baseUrl ?? (isFunction(mock) ? undefined : mock?.baseUrl),
+    override.mock?.baseUrl ?? (isFunction(mock) ? undefined : mock?.baseUrl),
   );
 
   const handlerName = `get${pascal(operationId)}MockHandler`;
diff --git a/packages/mock/src/msw/mocks.ts b/packages/mock/src/msw/mocks.ts
index c3c20e7bb..1971cad5f 100644
--- a/packages/mock/src/msw/mocks.ts
+++ b/packages/mock/src/msw/mocks.ts
@@ -22,7 +22,7 @@ const getMockPropertiesWithoutFunc = (properties: any, spec: OpenAPIObject) =>
       ? `(${value})()`
       : stringify(value as string)!;
 
-    acc[key] = implementation?.replaceAll(
+    acc[key] = implementation.replaceAll(
       /import_faker\.defaults|import_faker\.faker|_faker\.faker/g,
       'faker',
     );
@@ -59,7 +59,7 @@ const getMockWithoutFunc = (
         operations: Object.entries(override.operations).reduce<
           Exclude<MockOptions['operations'], undefined>
         >((acc, [key, value]) => {
-          if (value.mock?.properties) {
+          if (value?.mock?.properties) {
             acc[key] = {
               properties: getMockPropertiesWithoutFunc(
                 value.mock.properties,
@@ -77,7 +77,7 @@ const getMockWithoutFunc = (
         tags: Object.entries(override.tags).reduce<
           Exclude<MockOptions['tags'], undefined>
         >((acc, [key, value]) => {
-          if (value.mock?.properties) {
+          if (value?.mock?.properties) {
             acc[key] = {
               properties: getMockPropertiesWithoutFunc(
                 value.mock.properties,
@@ -151,13 +151,13 @@ export const getResponsesMockDefinition = ({
       { value: definition, originalSchema, example, examples, imports, isRef },
     ) => {
       if (
-        context.output.override?.mock?.useExamples ||
+        context.output.override.mock?.useExamples ||
         mockOptions?.useExamples
       ) {
         let exampleValue =
-          example ||
-          originalSchema?.example ||
-          Object.values(examples || {})[0] ||
+          example ??
+          originalSchema?.example ??
+          Object.values(examples ?? {})[0] ??
           originalSchema?.examples?.[0];
         exampleValue = exampleValue?.value ?? exampleValue;
         if (exampleValue) {
@@ -207,9 +207,7 @@ export const getResponsesMockDefinition = ({
 
       acc.imports.push(...scalar.imports);
       acc.definitions.push(
-        transformer
-          ? transformer(scalar.value, returnType)
-          : scalar.value.toString(),
+        transformer ? transformer(scalar.value, returnType) : scalar.value,
       );
 
       return acc;
@@ -275,9 +273,9 @@ export const getMockOptionsDataOverride = (
   override: NormalizedOverrideOutput,
 ) => {
   const responseOverride =
-    override?.operations?.[operationId]?.mock?.data ||
+    override.operations[operationId]?.mock?.data ??
     operationTags
-      .map((operationTag) => override?.tags?.[operationTag]?.mock?.data)
+      .map((operationTag) => override.tags[operationTag]?.mock?.data)
       .find((e) => e !== undefined);
   const implementation = isFunction(responseOverride)
     ? `(${responseOverride})()`
diff --git a/packages/mock/src/types.ts b/packages/mock/src/types.ts
index d35d6cf35..02cabe192 100644
--- a/packages/mock/src/types.ts
+++ b/packages/mock/src/types.ts
@@ -10,8 +10,9 @@ export interface MockDefinition {
   includedProperties?: string[];
 }
 
-export type MockSchemaObject = SchemaObject & {
+export type MockSchemaObject = Omit<SchemaObject, 'enum'> & {
   name: string;
   path?: string;
   isRef?: boolean;
+  enum?: string[];
 };
diff --git a/packages/swr/src/client.ts b/packages/swr/src/client.ts
index 4773b6d72..d14564567 100644
--- a/packages/swr/src/client.ts
+++ b/packages/swr/src/client.ts
@@ -62,9 +62,9 @@ const generateAxiosRequestFunction = (
   }: GeneratorVerbOptions,
   { route, context }: GeneratorOptions,
 ) => {
-  const isRequestOptions = override?.requestOptions !== false;
-  const isFormData = !override?.formData.disabled;
-  const isFormUrlEncoded = override?.formUrlEncoded !== false;
+  const isRequestOptions = override.requestOptions !== false;
+  const isFormData = !override.formData.disabled;
+  const isFormUrlEncoded = override.formUrlEncoded !== false;
   const isExactOptionalPropertyTypes =
     !!context.output.tsconfig?.compilerOptions?.exactOptionalPropertyTypes;
   const isSyntheticDefaultImportsAllowed = isSyntheticDefaultImportsAllow(
@@ -94,7 +94,7 @@ const generateAxiosRequestFunction = (
     });
 
     const propsImplementation =
-      mutator?.bodyTypeName && body.definition
+      mutator.bodyTypeName && body.definition
         ? toObjectString(props, 'implementation').replace(
             new RegExp(`(\\w*):\\s?${body.definition}`),
             `$1: ${mutator.bodyTypeName}<${body.definition}>`,
@@ -103,7 +103,7 @@ const generateAxiosRequestFunction = (
 
     const requestOptions = isRequestOptions
       ? generateMutatorRequestOptions(
-          override?.requestOptions,
+          override.requestOptions,
           mutator.hasSecondArg,
         )
       : '';
@@ -129,11 +129,11 @@ const generateAxiosRequestFunction = (
     queryParams,
     response,
     verb,
-    requestOptions: override?.requestOptions,
+    requestOptions: override.requestOptions,
     isFormData,
     isFormUrlEncoded,
     paramsSerializer,
-    paramsSerializerOptions: override?.paramsSerializerOptions,
+    paramsSerializerOptions: override.paramsSerializerOptions,
     isExactOptionalPropertyTypes,
     hasSignal: false,
   });
@@ -161,7 +161,7 @@ export const getSwrRequestOptions = (
     return httpClient === OutputHttpClient.AXIOS
       ? 'axios?: AxiosRequestConfig'
       : 'fetch?: RequestInit';
-  } else if (mutator?.hasSecondArg) {
+  } else if (mutator.hasSecondArg) {
     return `request?: SecondParameter<typeof ${mutator.name}>`;
   } else {
     return '';
@@ -193,7 +193,7 @@ export const getSwrRequestSecondArg = (
     return httpClient === OutputHttpClient.AXIOS
       ? 'axios: axiosOptions'
       : 'fetch: fetchOptions';
-  } else if (mutator?.hasSecondArg) {
+  } else if (mutator.hasSecondArg) {
     return 'request: requestOptions';
   } else {
     return '';
@@ -208,7 +208,7 @@ export const getHttpRequestSecondArg = (
     return httpClient === OutputHttpClient.AXIOS
       ? `axiosOptions`
       : `fetchOptions`;
-  } else if (mutator?.hasSecondArg) {
+  } else if (mutator.hasSecondArg) {
     return 'requestOptions';
   } else {
     return '';
diff --git a/packages/swr/src/index.ts b/packages/swr/src/index.ts
index b46c8e70e..3c9e6e596 100644
--- a/packages/swr/src/index.ts
+++ b/packages/swr/src/index.ts
@@ -387,7 +387,7 @@ const generateSwrHook = (
   }: GeneratorVerbOptions,
   { route, context }: GeneratorOptions,
 ) => {
-  const isRequestOptions = override?.requestOptions !== false;
+  const isRequestOptions = override.requestOptions !== false;
   const httpClient = context.output.httpClient;
   const doc = jsDoc({ summary, deprecated });
 
@@ -523,7 +523,7 @@ export const ${swrKeyFnName} = (${queryKeyProps}) => [\`${route}\`${
     const swrMutationFetcherType = getSwrMutationFetcherType(
       response,
       httpClient,
-      override.fetch?.includeHttpResponseReturnType,
+      override.fetch.includeHttpResponseReturnType,
       operationName,
       mutator,
     );
@@ -594,13 +594,6 @@ export const ${swrMutationFetcherName} = (${queryKeyProps} ${swrMutationFetcherO
     }] as const;
 `;
 
-    const swrMutationFetcherType = getSwrMutationFetcherType(
-      response,
-      httpClient,
-      override.fetch?.includeHttpResponseReturnType,
-      operationName,
-      mutator,
-    );
     const swrMutationFetcherOptionType = getSwrMutationFetcherOptionType(
       httpClient,
       mutator,
diff --git a/packages/tsdown.base.ts b/packages/tsdown.base.ts
index 5d6b37965..498881d94 100644
--- a/packages/tsdown.base.ts
+++ b/packages/tsdown.base.ts
@@ -1,6 +1,6 @@
-import type { UserConfig } from 'tsdown';
+import type { Options } from 'tsdown';
 
-export const baseOptions: UserConfig = {
+export const baseOptions: Options = {
   entry: ['src/index.ts'],
   target: 'node22.18',
   format: 'esm',
diff --git a/packages/zod/src/compatibleV4.test.ts b/packages/zod/src/compatible-v4.test.ts
similarity index 99%
rename from packages/zod/src/compatibleV4.test.ts
rename to packages/zod/src/compatible-v4.test.ts
index 050a7f887..8cd00754f 100644
--- a/packages/zod/src/compatibleV4.test.ts
+++ b/packages/zod/src/compatible-v4.test.ts
@@ -7,7 +7,7 @@ import {
   getZodDateTimeFormat,
   getZodTimeFormat,
   isZodVersionV4,
-} from './compatibleV4';
+} from './compatible-v4';
 
 describe('isZodVersionV4', () => {
   it('should return false when zod is not in package.json', () => {
diff --git a/packages/zod/src/compatibleV4.ts b/packages/zod/src/compatible-v4.ts
similarity index 100%
rename from packages/zod/src/compatibleV4.ts
rename to packages/zod/src/compatible-v4.ts
diff --git a/packages/zod/src/index.ts b/packages/zod/src/index.ts
index 3396bd505..c94dd3f82 100644
--- a/packages/zod/src/index.ts
+++ b/packages/zod/src/index.ts
@@ -10,6 +10,7 @@ import {
   type GeneratorOptions,
   type GeneratorVerbOptions,
   getNumberWord,
+  getPropertySafe,
   getRefInfo,
   isBoolean,
   isObject,
@@ -20,15 +21,19 @@ import {
   stringify,
   type ZodCoerceType,
 } from '@orval/core';
-import type {
-  ParameterObject,
-  PathItemObject,
-  ReferenceObject,
-  RequestBodyObject,
-  ResponseObject,
-  SchemaObject,
+import {
+  isSchemaObject,
+  type ParameterObject,
+  type PathItemObject,
+  type ReferenceObject,
+  type RequestBodyObject,
+  type ResponseObject,
+  type SchemaObject,
 } from 'openapi3-ts/oas30';
-import type { SchemaObject as SchemaObject31 } from 'openapi3-ts/oas31';
+import {
+  isSchemaObject as isSchemaObject31,
+  type SchemaObject as SchemaObject31,
+} from 'openapi3-ts/oas31';
 import { unique } from 'remeda';
 
 import {
@@ -38,7 +43,7 @@ import {
   getZodDateTimeFormat,
   getZodTimeFormat,
   isZodVersionV4,
-} from './compatibleV4';
+} from './compatible-v4';
 
 const ZOD_DEPENDENCIES: GeneratorDependency[] = [
   {
@@ -195,6 +200,8 @@ export const generateZodValidationSchemaDefinition = (
   const type = resolveZodType(schema);
   const required = rules?.required ?? false;
   const nullable =
+    // changing to ?? here changes behavior - so don't
+    // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
     ('nullable' in schema && schema.nullable) ||
     (Array.isArray(schema.type) && schema.type.includes('null'));
   const min = schema.minimum ?? schema.minLength ?? schema.minItems;
@@ -284,6 +291,8 @@ export const generateZodValidationSchemaDefinition = (
       context.output.override.useDates;
 
     if (isDateType) {
+      // openapi3-ts's SchemaObject defines default as 'any'
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
       defaultValue = `new Date("${escape(schema.default)}")`;
     } else if (isObject(schema.default)) {
       const entries = Object.entries(schema.default)
@@ -299,11 +308,19 @@ export const generateZodValidationSchemaDefinition = (
             return `${key}: [${arrayItems.join(', ')}]`;
           }
 
-          return `${key}: ${value}`;
+          if (
+            value === null ||
+            value === undefined ||
+            typeof value === 'number' ||
+            typeof value === 'boolean'
+          )
+            return `${key}: ${value}`;
         })
         .join(', ');
       defaultValue = `{ ${entries} }`;
     } else {
+      // openapi3-ts's SchemaObject defines default as 'any'
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
       const rawStringified = stringify(schema.default);
       defaultValue =
         rawStringified === undefined
@@ -326,12 +343,12 @@ export const generateZodValidationSchemaDefinition = (
 
   // Handle multi-type schemas (OpenAPI 3.1+ type arrays)
   if (typeof type === 'object' && 'multiType' in type) {
-    const types = (type as { multiType: string[] }).multiType;
+    const types = type.multiType;
     functions.push([
       'oneOf',
       types.map((t) =>
         generateZodValidationSchemaDefinition(
-          { ...schema, type: t as any },
+          { ...schema, type: t },
           context,
           name,
           strict,
@@ -392,7 +409,7 @@ export const generateZodValidationSchemaDefinition = (
 
             if (
               schema.items &&
-              (max || Number.POSITIVE_INFINITY) > schema31.prefixItems.length
+              (max ?? Number.POSITIVE_INFINITY) > schema31.prefixItems.length
             ) {
               // only add zod.rest() if number of tuple elements can exceed provided prefixItems:
               functions.push([
@@ -430,7 +447,7 @@ export const generateZodValidationSchemaDefinition = (
         break;
       }
       case 'string': {
-        if (schema.enum && type === 'string') {
+        if (schema.enum) {
           break;
         }
 
@@ -457,7 +474,7 @@ export const generateZodValidationSchemaDefinition = (
               'uri',
               'hostname',
               'uuid',
-            ].includes(schema.format || '')
+            ].includes(schema.format ?? '')
           ) {
             if ('const' in schema) {
               functions.push(['literal', `"${schema.const}"`]);
@@ -482,24 +499,18 @@ export const generateZodValidationSchemaDefinition = (
         }
 
         if (schema.format === 'time') {
-          const options = context.output.override.zod?.timeOptions;
+          const options = context.output.override.zod.timeOptions;
           const formatAPI = getZodTimeFormat(isZodV4);
 
-          functions.push([
-            formatAPI,
-            options ? JSON.stringify(options) : undefined,
-          ]);
+          functions.push([formatAPI, JSON.stringify(options)]);
           break;
         }
 
         if (schema.format === 'date-time') {
-          const options = context.output.override.zod?.dateTimeOptions;
+          const options = context.output.override.zod.dateTimeOptions;
           const formatAPI = getZodDateTimeFormat(isZodV4);
 
-          functions.push([
-            formatAPI,
-            options ? JSON.stringify(options) : undefined,
-          ]);
+          functions.push([formatAPI, JSON.stringify(options)]);
           break;
         }
 
@@ -520,7 +531,6 @@ export const generateZodValidationSchemaDefinition = (
 
         break;
       }
-      case 'object':
       default: {
         if (schema.properties) {
           const objectType = getObjectFunctionName(isZodV4, strict);
@@ -707,7 +717,7 @@ export const parseZodValidationSchemaDefinition = (
             consts: argConsts,
           }: { functions: [string, any][]; consts: string[] },
         ) => {
-          const value = functions.map(parseProperty).join('');
+          const value = functions.map((prop) => parseProperty(prop)).join('');
           const valueWithZod = `${value.startsWith('.') ? 'zod' : ''}${value}`;
 
           if (argConsts.length > 0) {
@@ -729,7 +739,7 @@ export const parseZodValidationSchemaDefinition = (
     if (fn === 'oneOf' || fn === 'anyOf') {
       // Can't use zod.union() with a single item
       if (args.length === 1) {
-        return args[0].functions.map(parseProperty).join('');
+        return args[0].functions.map((prop) => parseProperty(prop)).join('');
       }
 
       const union = args.map(
@@ -740,10 +750,10 @@ export const parseZodValidationSchemaDefinition = (
           functions: [string, any][];
           consts: string[];
         }) => {
-          const value = functions.map(parseProperty).join('');
+          const value = functions.map((prop) => parseProperty(prop)).join('');
           const valueWithZod = `${value.startsWith('.') ? 'zod' : ''}${value}`;
           // consts are missing here
-          consts += argConsts?.join('\n');
+          consts += argConsts.join('\n');
           return valueWithZod;
         },
       );
@@ -752,7 +762,7 @@ export const parseZodValidationSchemaDefinition = (
     }
 
     if (fn === 'additionalProperties') {
-      const value = args.functions.map(parseProperty).join('');
+      const value = args.functions.map((prop) => parseProperty(prop)).join('');
       const valueWithZod = `${value.startsWith('.') ? 'zod' : ''}${value}`;
       consts += args.consts;
       return `zod.record(zod.string(), ${valueWithZod})`;
@@ -765,7 +775,7 @@ export const parseZodValidationSchemaDefinition = (
 ${Object.entries(args)
   .map(([key, schema]) => {
     const value = (schema as ZodValidationSchemaDefinition).functions
-      .map(parseProperty)
+      .map((prop) => parseProperty(prop))
       .join('');
     consts += (schema as ZodValidationSchemaDefinition).consts.join('\n');
     return `  "${key}": ${value.startsWith('.') ? 'zod' : ''}${value}`;
@@ -774,7 +784,7 @@ ${Object.entries(args)
 })`;
     }
     if (fn === 'array') {
-      const value = args.functions.map(parseProperty).join('');
+      const value = args.functions.map((prop) => parseProperty(prop)).join('');
       if (typeof args.consts === 'string') {
         consts += args.consts;
       } else if (Array.isArray(args.consts)) {
@@ -790,13 +800,13 @@ ${Object.entries(args)
     if (fn === 'tuple') {
       return `zod.tuple([${(args as ZodValidationSchemaDefinition[])
         .map((x) => {
-          const value = x.functions.map(parseProperty).join('');
+          const value = x.functions.map((prop) => parseProperty(prop)).join('');
           return `${value.startsWith('.') ? 'zod' : ''}${value}`;
         })
         .join(',\n')}])`;
     }
     if (fn === 'rest') {
-      return `.rest(zod${(args as ZodValidationSchemaDefinition).functions.map(parseProperty)})`;
+      return `.rest(zod${(args as ZodValidationSchemaDefinition).functions.map((prop) => parseProperty(prop))})`;
     }
     const shouldCoerceType =
       coerceTypes &&
@@ -816,7 +826,7 @@ ${Object.entries(args)
 
   consts += input.consts.join('\n');
 
-  const schema = input.functions.map(parseProperty).join('');
+  const schema = input.functions.map((prop) => parseProperty(prop)).join('');
   const value = preprocess
     ? `.preprocess(${preprocess.name}, ${
         schema.startsWith('.') ? 'zod' : ''
@@ -825,7 +835,7 @@ ${Object.entries(args)
 
   const zod = `${value.startsWith('.') ? 'zod' : ''}${value}`;
   // Some export consts includes `,` as prefix, adding replace to remove those
-  if (consts?.includes(',export')) {
+  if (consts.includes(',export')) {
     consts = consts.replaceAll(',export', '\nexport');
   }
   return { zod, consts };
@@ -853,7 +863,7 @@ const deference = (
   const childContext: ContextSpecs = {
     ...context,
     ...(refName
-      ? { parents: [...(context.parents || []), refName] }
+      ? { parents: [...(context.parents ?? []), refName] }
       : undefined),
   };
 
@@ -930,7 +940,7 @@ const parseBodyAndResponse = ({
   ).schema;
 
   const schema =
-    resolvedRef.content?.['application/json']?.schema ||
+    resolvedRef.content?.['application/json']?.schema ??
     resolvedRef.content?.['multipart/form-data']?.schema;
 
   if (!schema) {
@@ -1071,7 +1081,7 @@ const parseParameters = ({
         schema,
         context,
         camel(`${operationName}-${parameter.in}-${parameter.name}`),
-        mapStrict[parameter.in as 'path' | 'query' | 'header'] ?? false,
+        getPropertySafe(mapStrict, parameter.in).value ?? false,
         isZodV4,
         {
           required: parameter.required,
@@ -1346,9 +1356,9 @@ const generateZodRoute = async (
             parsedBody.isArray
               ? `export const ${operationName}BodyItem = ${inputBody.zod}
 export const ${operationName}Body = zod.array(${operationName}BodyItem)${
-                  parsedBody.rules?.min ? `.min(${parsedBody.rules?.min})` : ''
+                  parsedBody.rules?.min ? `.min(${parsedBody.rules.min})` : ''
                 }${
-                  parsedBody.rules?.max ? `.max(${parsedBody.rules?.max})` : ''
+                  parsedBody.rules?.max ? `.max(${parsedBody.rules.max})` : ''
                 }`
               : `export const ${operationName}Body = ${inputBody.zod}`,
           ]
@@ -1367,11 +1377,11 @@ export const ${operationName}Body = zod.array(${operationName}BodyItem)${
                     }
 export const ${operationResponse} = zod.array(${operationResponse}Item)${
                       parsedResponses[index].rules?.min
-                        ? `.min(${parsedResponses[index].rules?.min})`
+                        ? `.min(${parsedResponses[index].rules.min})`
                         : ''
                     }${
                       parsedResponses[index].rules?.max
-                        ? `.max(${parsedResponses[index].rules?.max})`
+                        ? `.max(${parsedResponses[index].rules.max})`
                         : ''
                     }`
                   : `export const ${operationResponse} = ${inputResponse.zod}`,
diff --git a/packages/zod/src/zod.test.ts b/packages/zod/src/zod.test.ts
index 402584c9c..ad3d71997 100644
--- a/packages/zod/src/zod.test.ts
+++ b/packages/zod/src/zod.test.ts
@@ -2119,7 +2119,7 @@ describe('generatePartOfSchemaGenerateZod', () => {
 });
 
 describe('parsePrefixItemsArrayAsTupleZod', () => {
-  it('generates correctly', async () => {
+  it('generates correctly', () => {
     const arrayWithPrefixItemsSchema: SchemaObject31 = {
       type: 'array',
       prefixItems: [{ type: 'string' }, {}],
@@ -2171,7 +2171,7 @@ describe('parsePrefixItemsArrayAsTupleZod', () => {
 });
 
 describe('parsePrefixItemsArrayAsTupleZod', () => {
-  it('correctly omits rest', async () => {
+  it('correctly omits rest', () => {
     const arrayWithPrefixItemsSchema: SchemaObject31 = {
       type: 'array',
       prefixItems: [{ type: 'string' }, {}],
diff --git a/samples/hono/composite-routes-with-tags-split/package.json b/samples/hono/composite-routes-with-tags-split/package.json
index 8bf4a119f..48b570288 100644
--- a/samples/hono/composite-routes-with-tags-split/package.json
+++ b/samples/hono/composite-routes-with-tags-split/package.json
@@ -2,6 +2,7 @@
   "name": "@hono/composite-routes-with-tags-split",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "dev": "wrangler dev src/app.ts --ip 0.0.0.0",
     "deploy": "wrangler deploy --minify src/index.ts",
diff --git a/samples/hono/hono-with-fetch-client/package.json b/samples/hono/hono-with-fetch-client/package.json
index 25fc2f963..8bc9d6655 100644
--- a/samples/hono/hono-with-fetch-client/package.json
+++ b/samples/hono/hono-with-fetch-client/package.json
@@ -2,6 +2,7 @@
   "name": "hono-with-fetch-client",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "generate-api": "orval"
   },
diff --git a/samples/hono/hono-with-zod/package.json b/samples/hono/hono-with-zod/package.json
index b858bb0f7..558cb6ed0 100644
--- a/samples/hono/hono-with-zod/package.json
+++ b/samples/hono/hono-with-zod/package.json
@@ -1,6 +1,7 @@
 {
   "name": "hono-with-zod",
   "private": true,
+  "type": "module",
   "scripts": {
     "dev": "wrangler dev src/index.ts",
     "deploy": "wrangler deploy --minify src/index.ts",
diff --git a/samples/mcp/petstore/package.json b/samples/mcp/petstore/package.json
index fcdd45f2e..9b7efd66c 100644
--- a/samples/mcp/petstore/package.json
+++ b/samples/mcp/petstore/package.json
@@ -2,6 +2,7 @@
   "name": "mcp-petstore",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "build": "tsc",
     "dev": "ts-node src/server.ts",
diff --git a/samples/next-app-with-fetch/package.json b/samples/next-app-with-fetch/package.json
index dd4a60780..885cd16cd 100644
--- a/samples/next-app-with-fetch/package.json
+++ b/samples/next-app-with-fetch/package.json
@@ -2,6 +2,7 @@
   "name": "next-app-with-fetch",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "dev": "next dev",
     "build": "next build",
diff --git a/samples/react-app-with-swr/basic/package.json b/samples/react-app-with-swr/basic/package.json
index bdb131adb..8c0ac02ca 100644
--- a/samples/react-app-with-swr/basic/package.json
+++ b/samples/react-app-with-swr/basic/package.json
@@ -2,6 +2,7 @@
   "name": "swr-basic",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "dependencies": {
     "@faker-js/faker": "^10.1.0",
     "@types/node": "^22.18.12",
diff --git a/samples/react-app/package.json b/samples/react-app/package.json
index 073308aa3..37caefb58 100644
--- a/samples/react-app/package.json
+++ b/samples/react-app/package.json
@@ -2,6 +2,7 @@
   "name": "react-app",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "start": "react-scripts start",
     "build": "react-scripts build",
diff --git a/samples/react-query/form-data-mutator/package.json b/samples/react-query/form-data-mutator/package.json
index fd7c070fd..38ec0e5ad 100644
--- a/samples/react-query/form-data-mutator/package.json
+++ b/samples/react-query/form-data-mutator/package.json
@@ -2,6 +2,7 @@
   "name": "react-query-form-data-mutator",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "generate-api": "orval",
     "test": "tsc --noEmit endpoints.ts"
diff --git a/samples/react-query/form-data/package.json b/samples/react-query/form-data/package.json
index 2ecea0ce1..b3b8347da 100644
--- a/samples/react-query/form-data/package.json
+++ b/samples/react-query/form-data/package.json
@@ -2,6 +2,7 @@
   "name": "react-query-form-data",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "generate-api": "orval",
     "test": "tsc --noEmit endpoints.ts"
diff --git a/samples/react-query/form-url-encoded-mutator/package.json b/samples/react-query/form-url-encoded-mutator/package.json
index 772758f89..38d3eb3f3 100644
--- a/samples/react-query/form-url-encoded-mutator/package.json
+++ b/samples/react-query/form-url-encoded-mutator/package.json
@@ -2,6 +2,7 @@
   "name": "react-query-form-url-encoded-mutator",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "generate-api": "orval",
     "test": "tsc --noEmit endpoints.ts"
diff --git a/samples/react-query/form-url-encoded/package.json b/samples/react-query/form-url-encoded/package.json
index 45e44d82c..929e856ce 100644
--- a/samples/react-query/form-url-encoded/package.json
+++ b/samples/react-query/form-url-encoded/package.json
@@ -2,6 +2,7 @@
   "name": "react-query-form-url-encoded",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "generate-api": "orval",
     "test": "tsc --noEmit endpoints.ts"
diff --git a/samples/react-query/hook-mutator/package.json b/samples/react-query/hook-mutator/package.json
index f9a1c4e72..4362fce8d 100644
--- a/samples/react-query/hook-mutator/package.json
+++ b/samples/react-query/hook-mutator/package.json
@@ -2,6 +2,7 @@
   "name": "react-query-hook-mutator",
   "version": "8.0.0-rc.1",
   "private": true,
+  "type": "module",
   "scripts": {
     "generate-api": "orval",
     "test": "tsc --noEmit endpoints.ts"