diff --git a/package-lock.json b/package-lock.json
index ee32628..9a4a561 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,7 +10,6 @@
       "license": "MIT",
       "dependencies": {
         "@asteasolutions/zod-to-openapi": "^6.4.0",
-        "itty-router": "4.0.26",
         "js-yaml": "^4.1.0",
         "openapi3-ts": "^4.1.2",
         "zod": "^3.21.4"
@@ -31,6 +30,7 @@
         "eslint-config-prettier": "^8.8.0",
         "husky": "^7.0.2",
         "isomorphic-fetch": "^3.0.0",
+        "itty-router": "^5.0.17",
         "jest": "^29.0.0",
         "jest-openapi": "^0.14.2",
         "pinst": "^2.1.6",
@@ -4180,9 +4180,10 @@
       }
     },
     "node_modules/itty-router": {
-      "version": "4.0.26",
-      "resolved": "https://registry.npmjs.org/itty-router/-/itty-router-4.0.26.tgz",
-      "integrity": "sha512-GBcmhxQRvIQ7fuzXPlvfeQcN6O7VGhctzdG9WHIcEcaRYH4FvDpMxuSWRIAxQrIM+nxtfxK0/bR78ATvb4LC5Q=="
+      "version": "5.0.17",
+      "resolved": "https://registry.npmjs.org/itty-router/-/itty-router-5.0.17.tgz",
+      "integrity": "sha512-ZHnPI0OOyTTLuNp2FdciejYaK4Wl3ZV3O0yEm8njOGggh/k/ek3BL7X2I5YsCOfc5vLhIJgj3Z4pUtLs6k9Ucg==",
+      "dev": true
     },
     "node_modules/jest": {
       "version": "29.0.0",
@@ -10702,9 +10703,10 @@
       }
     },
     "itty-router": {
-      "version": "4.0.26",
-      "resolved": "https://registry.npmjs.org/itty-router/-/itty-router-4.0.26.tgz",
-      "integrity": "sha512-GBcmhxQRvIQ7fuzXPlvfeQcN6O7VGhctzdG9WHIcEcaRYH4FvDpMxuSWRIAxQrIM+nxtfxK0/bR78ATvb4LC5Q=="
+      "version": "5.0.17",
+      "resolved": "https://registry.npmjs.org/itty-router/-/itty-router-5.0.17.tgz",
+      "integrity": "sha512-ZHnPI0OOyTTLuNp2FdciejYaK4Wl3ZV3O0yEm8njOGggh/k/ek3BL7X2I5YsCOfc5vLhIJgj3Z4pUtLs6k9Ucg==",
+      "dev": true
     },
     "jest": {
       "version": "29.0.0",
diff --git a/package.json b/package.json
index 7448119..46b1a26 100644
--- a/package.json
+++ b/package.json
@@ -81,6 +81,7 @@
     "eslint-config-prettier": "^8.8.0",
     "husky": "^7.0.2",
     "isomorphic-fetch": "^3.0.0",
+    "itty-router": "^5.0.17",
     "jest": "^29.0.0",
     "jest-openapi": "^0.14.2",
     "pinst": "^2.1.6",
@@ -93,7 +94,6 @@
   },
   "dependencies": {
     "@asteasolutions/zod-to-openapi": "^6.4.0",
-    "itty-router": "4.0.26",
     "js-yaml": "^4.1.0",
     "openapi3-ts": "^4.1.2",
     "zod": "^3.21.4"
diff --git a/src/openapi.ts b/src/openapi.ts
index d3e8fe0..cf3827b 100644
--- a/src/openapi.ts
+++ b/src/openapi.ts
@@ -1,12 +1,5 @@
 import { getReDocUI, getSwaggerUI } from './ui'
-import {
-  IRequest,
-  RouteHandler,
-  Router,
-  RouterType,
-  UniversalRoute,
-} from 'itty-router'
-import { APIType, AuthType, RouterOptions, SchemaVersion } from './types'
+import { RouterOptions } from './types'
 import {
   OpenApiGeneratorV3,
   OpenApiGeneratorV31,
@@ -15,283 +8,271 @@ import {
 import { OpenAPIRegistryMerger } from './zod/registry'
 import { z } from 'zod'
 import { OpenAPIObject } from 'openapi3-ts/oas31'
-import { OpenAPIRoute } from './route'
 import yaml from 'js-yaml'
 
-export type Route = <
-  RequestType = IRequest,
-  Args extends any[] = any[],
-  RT = OpenAPIRouterType,
->(
-  path: string,
-  ...handlers: (RouteHandler<RequestType, Args> | OpenAPIRouterType | any)[] // TODO: fix this any to be instance of OpenAPIRoute
-) => RT
-
-export type OpenAPIRouterType<R = Route, Args extends any[] = any[]> = {
-  original: RouterType<R>
-  schema: OpenAPIObject
+export type OpenAPIRouterType<M> = {
+  original: M
+  options: RouterOptions
+  registry: OpenAPIRegistryMerger
+}
+
+export class OpenAPIHandler {
+  router: any
+  options: RouterOptions
   registry: OpenAPIRegistryMerger
-} & RouterType<R>
-
-// helper function to detect equality in types (used to detect custom Request on router)
-type Equal<X, Y> =
-  (<T>() => T extends X ? 1 : 2) extends <T>() => T extends Y ? 1 : 2
-    ? true
-    : false
-
-export function OpenAPIRouter<
-  RequestType = IRequest,
-  Args extends any[] = any[],
-  RouteType = Equal<RequestType, IRequest> extends true
-    ? Route
-    : UniversalRoute<RequestType, Args>,
->(options?: RouterOptions): OpenAPIRouterType<RouteType, Args> {
-  const registry: OpenAPIRegistryMerger = new OpenAPIRegistryMerger()
-
-  const getGeneratedSchema = (): OpenAPIObject => {
+
+  constructor(router: any, options?: RouterOptions) {
+    this.router = router
+    this.options = options || {}
+    this.registry = new OpenAPIRegistryMerger()
+
+    this.createDocsRoutes()
+  }
+
+  createDocsRoutes() {
+    if (this.options?.docs_url !== null && this.options?.openapi_url !== null) {
+      this.router.get(this.options?.docs_url || '/docs', () => {
+        return new Response(
+          getSwaggerUI(
+            (this.options?.base || '') +
+              (this.options?.openapi_url || '/openapi.json')
+          ),
+          {
+            headers: {
+              'content-type': 'text/html; charset=UTF-8',
+            },
+            status: 200,
+          }
+        )
+      })
+    }
+
+    if (
+      this.options?.redoc_url !== null &&
+      this.options?.openapi_url !== null
+    ) {
+      this.router.get(this.options?.redoc_url || '/redocs', () => {
+        return new Response(
+          getReDocUI(
+            (this.options?.base || '') +
+              (this.options?.openapi_url || '/openapi.json')
+          ),
+          {
+            headers: {
+              'content-type': 'text/html; charset=UTF-8',
+            },
+            status: 200,
+          }
+        )
+      })
+    }
+
+    if (this.options?.openapi_url !== null) {
+      this.router.get(this.options?.openapi_url || '/openapi.json', () => {
+        return new Response(JSON.stringify(this.getGeneratedSchema()), {
+          headers: {
+            'content-type': 'application/json;charset=UTF-8',
+          },
+          status: 200,
+        })
+      })
+
+      this.router.get(
+        (this.options?.openapi_url || '/openapi.json').replace(
+          '.json',
+          '.yaml'
+        ),
+        () => {
+          return new Response(yaml.dump(this.getGeneratedSchema()), {
+            headers: {
+              'content-type': 'text/yaml;charset=UTF-8',
+            },
+            status: 200,
+          })
+        }
+      )
+    }
+  }
+
+  getGeneratedSchema(): OpenAPIObject {
     let openapiGenerator: any = OpenApiGeneratorV31
-    if (options?.openapiVersion === '3') openapiGenerator = OpenApiGeneratorV3
+    if (this.options?.openapiVersion === '3')
+      openapiGenerator = OpenApiGeneratorV3
 
-    const generator = new openapiGenerator(registry.definitions)
+    const generator = new openapiGenerator(this.registry.definitions)
 
     return generator.generateDocument({
-      openapi: options?.openapiVersion === '3' ? '3.0.3' : '3.1.0',
+      openapi: this.options?.openapiVersion === '3' ? '3.0.3' : '3.1.0',
       info: {
-        version: options?.schema?.info?.version || '1.0.0',
-        title: options?.schema?.info?.title || 'OpenAPI',
-        ...options?.schema?.info,
+        version: this.options?.schema?.info?.version || '1.0.0',
+        title: this.options?.schema?.info?.title || 'OpenAPI',
+        ...this.options?.schema?.info,
       },
-      ...options?.schema,
+      ...this.options?.schema,
     })
   }
 
-  const routerToUse = options?.baseRouter || Router
+  registerNestedRouter(params: {
+    method: string
+    path: string
+    nestedRouter: any
+  }) {
+    this.registry.merge(params.nestedRouter.registry)
 
-  const router = routerToUse({ base: options?.base, routes: options?.routes })
+    return [params.nestedRouter.fetch]
+  }
 
-  const routerProxy: OpenAPIRouterType<RouteType, Args> = new Proxy(router, {
-    // @ts-expect-error (we're adding an expected prop "path" to the get)
-    get: (target: any, prop: string, receiver: object, path: string) => {
-      if (prop === 'original') {
-        return router
-      }
-      if (prop === 'schema') {
-        return getGeneratedSchema()
+  parseRoute(path: string): string {
+    return ((this.options.base || '') + path)
+      .replaceAll(/\/+(\/|$)/g, '$1') // strip double & trailing splash
+      .replaceAll(/:(\w+)/g, '{$1}') // convert parameters into openapi compliant
+  }
+
+  registerRoute(params: { method: string; path: string; handlers: any[] }) {
+    const parsedRoute = this.parseRoute(params.path)
+
+    // @ts-ignore
+    let schema: RouteConfig = undefined
+    // @ts-ignore
+    let operationId: string = undefined
+
+    for (const handler of params.handlers) {
+      if (handler.name) {
+        operationId = `${params.method}_${handler.name}`
       }
-      if (prop === 'registry') {
-        return registry
+
+      if (handler.getSchemaZod) {
+        schema = handler.getSchemaZod()
+        break
       }
+    }
 
-      return (
-        route: string,
-        ...handlers: RouteHandler<RequestType, Args>[] &
-          (typeof OpenAPIRoute)[] &
-          OpenAPIRouterType<RouteType, Args>[]
-      ) => {
-        if (prop !== 'handle') {
-          if (handlers.length === 1 && handlers[0].registry) {
-            const nestedRouter = handlers[0]
+    if (operationId === undefined) {
+      operationId = `${params.method}_${parsedRoute.replaceAll('/', '_')}`
+    }
 
-            // Merge inner router definitions into outer router
-            registry.merge(nestedRouter.registry)
-          } else if (prop !== 'all') {
-            const parsedRoute = ((options?.base || '') + route)
-              .replaceAll(/\/+(\/|$)/g, '$1') // strip double & trailing splash
-              .replaceAll(/:(\w+)/g, '{$1}') // convert parameters into openapi compliant
-
-            // @ts-ignore
-            let schema: RouteConfig = undefined
-            // @ts-ignore
-            let operationId: string = undefined
-
-            for (const handler of handlers) {
-              if (handler.name) {
-                operationId = `${prop.toString()}_${handler.name}`
-              }
-
-              if (handler.getSchemaZod) {
-                schema = handler.getSchemaZod()
-                break
-              }
-            }
-
-            if (operationId === undefined) {
-              operationId = `${prop.toString()}_${route.replaceAll('/', '_')}`
-            }
-
-            if (schema === undefined) {
-              // No schema for this route, try to guest the parameters
-
-              // @ts-ignore
-              schema = {
-                operationId: operationId,
-                responses: {
-                  200: {
-                    description: 'Object with user data.',
-                  },
-                },
-              }
-
-              const params = ((options?.base || '') + route).match(/:(\w+)/g)
-              if (params) {
-                schema.request = {
-                  // TODO: make sure this works
-                  params: z.object(
-                    params.reduce(
-                      // matched parameters start with ':' so replace the first occurrence with nothing
-                      (obj, item) =>
-                        Object.assign(obj, {
-                          [item.replace(':', '')]: z.string(),
-                        }),
-                      {}
-                    )
-                  ),
-                }
-              }
-            } else {
-              // Schema was provided in the endpoint
-              if (!schema.operationId) {
-                if (
-                  options?.generateOperationIds === false &&
-                  !schema.operationId
-                ) {
-                  throw new Error(`Route ${route} don't have operationId set!`)
-                }
-
-                schema.operationId = operationId
-              }
-            }
-
-            registry.registerPath({
-              ...schema,
-              // @ts-ignore
-              method: prop.toString(),
-              path: parsedRoute,
-            })
-          }
-        }
+    if (schema === undefined) {
+      // No schema for this route, try to guest the parameters
 
-        // console.log(`${prop.toString()}`)
-        // @ts-ignore
-        // console.log(Reflect.routes)
-        return Reflect.get(
-          target,
-          prop,
-          receiver
-          // path
-        )(
-          route,
-          ...handlers.map((handler: any) => {
-            if (handler.handle) {
-              // Nested router
-              return handler.handle
-            }
-
-            if (handler.isRoute) {
-              // console.log(handler)
-              return (...params: any[]) =>
-                new handler({
-                  // raiseUnknownParameters: openapiConfig.raiseUnknownParameters,  TODO
-                  skipValidation: options?.skipValidation,
-                }).execute(...params)
-            }
-
-            // console.log(handler())
-            return handler
-          })
-        )
+      // @ts-ignore
+      schema = {
+        operationId: operationId,
+        responses: {
+          200: {
+            description: 'Object with user data.',
+          },
+        },
       }
-    },
-  })
 
-  if (options?.docs_url !== null && options?.openapi_url !== null) {
-    router.get(options?.docs_url || '/docs', () => {
-      return new Response(
-        getSwaggerUI(
-          (options?.base || '') + (options?.openapi_url || '/openapi.json')
-        ),
-        {
-          headers: {
-            'content-type': 'text/html; charset=UTF-8',
-          },
-          status: 200,
-        }
+      const parsedParams = ((this.options.base || '') + params.path).match(
+        /:(\w+)/g
       )
-    })
-  }
-
-  if (options?.redoc_url !== null && options?.openapi_url !== null) {
-    router.get(options?.redoc_url || '/redocs', () => {
-      return new Response(
-        getReDocUI(
-          (options?.base || '') + (options?.openapi_url || '/openapi.json')
-        ),
-        {
-          headers: {
-            'content-type': 'text/html; charset=UTF-8',
-          },
-          status: 200,
+      if (parsedParams) {
+        schema.request = {
+          // TODO: make sure this works
+          params: z.object(
+            parsedParams.reduce(
+              // matched parameters start with ':' so replace the first occurrence with nothing
+              (obj, item) =>
+                Object.assign(obj, {
+                  [item.replace(':', '')]: z.string(),
+                }),
+              {}
+            )
+          ),
+        }
+      }
+    } else {
+      // Schema was provided in the endpoint
+      if (!schema.operationId) {
+        if (
+          this.options?.generateOperationIds === false &&
+          !schema.operationId
+        ) {
+          throw new Error(`Route ${params.path} don't have operationId set!`)
         }
-      )
-    })
-  }
 
-  if (options?.openapi_url !== null) {
-    router.get(options?.openapi_url || '/openapi.json', () => {
-      return new Response(JSON.stringify(getGeneratedSchema()), {
-        headers: {
-          'content-type': 'application/json;charset=UTF-8',
-        },
-        status: 200,
-      })
+        schema.operationId = operationId
+      }
+    }
+
+    this.registry.registerPath({
+      ...schema,
+      // @ts-ignore
+      method: params.method,
+      path: parsedRoute,
     })
 
-    router.get(
-      (options?.openapi_url || '/openapi.json').replace('.json', '.yaml'),
-      () => {
-        return new Response(yaml.dump(getGeneratedSchema()), {
-          headers: {
-            'content-type': 'text/yaml;charset=UTF-8',
-          },
-          status: 200,
-        })
+    return params.handlers.map((handler: any) => {
+      if (handler.isRoute) {
+        // console.log(handler)
+        return (...params: any[]) =>
+          new handler({
+            // raiseUnknownParameters: openapiConfig.raiseUnknownParameters,  TODO
+            skipValidation: this.options?.skipValidation,
+          }).execute(...params)
       }
-    )
+
+      // console.log(handler())
+      return handler
+    })
   }
 
-  if (options?.aiPlugin && options?.openapi_url !== null) {
-    router.get('/.well-known/ai-plugin.json', (request: IRequest) => {
-      const schemaApi = {
-        type: APIType.OPENAPI,
-        has_user_authentication: false,
-        url: options?.openapi_url || '/openapi.json',
-        ...options?.aiPlugin?.api,
-      }
+  handleCommonProxy(target: any, prop: string, ...args: any[]) {
+    // This is a hack to allow older versions of wrangler to use this library
+    // https://github.com/cloudflare/workers-sdk/issues/5420
+    if (prop === 'middleware') {
+      return []
+    }
+
+    if (prop === 'original') {
+      return this.router
+    }
+    if (prop === 'schema') {
+      return this.getGeneratedSchema()
+    }
+    if (prop === 'registry') {
+      return this.registry
+    }
+
+    return undefined
+  }
+}
+
+export class IttyRouterOpenAPIHandler extends OpenAPIHandler {}
 
-      // Check if schema path is relative
-      if (!schemaApi.url.startsWith('http')) {
-        // dynamically add the host
-        schemaApi.url = `https://${request.headers.get('host')}${schemaApi.url}`
+export function fromIttyRouter<M>(
+  router: M,
+  options?: RouterOptions
+): M & OpenAPIRouterType<M> & any {
+  const openapiRouter = new IttyRouterOpenAPIHandler(router, options)
+
+  return new Proxy(router, {
+    get: (target: any, prop: string, ...args: any[]) => {
+      const _result = openapiRouter.handleCommonProxy(target, prop, ...args)
+      if (_result !== undefined) {
+        return _result
       }
 
-      return new Response(
-        JSON.stringify({
-          schema_version: SchemaVersion.V1,
-          auth: {
-            type: AuthType.NONE,
-          },
-          ...options?.aiPlugin,
-          api: schemaApi,
-        }),
-        {
-          headers: {
-            'content-type': 'application/json;charset=UTF-8',
-          },
-          status: 200,
+      return (route: string, ...handlers: any[]) => {
+        if (prop !== 'fetch') {
+          if (handlers.length === 1 && handlers[0].registry) {
+            handlers = openapiRouter.registerNestedRouter({
+              method: prop,
+              path: route,
+              nestedRouter: handlers[0],
+            })
+          } else if (prop !== 'all') {
+            handlers = openapiRouter.registerRoute({
+              method: prop,
+              path: route,
+              handlers: handlers,
+            })
+          }
         }
-      )
-    })
-  }
 
-  return routerProxy
+        return Reflect.get(target, prop, ...args)(route, ...handlers)
+      }
+    },
+  })
 }
diff --git a/src/types.ts b/src/types.ts
index 316e766..c7ee951 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,4 +1,4 @@
-import { RouteEntry } from 'itty-router'
+import { IRequest, RouteEntry } from 'itty-router'
 import { z, AnyZodObject, ZodType } from 'zod'
 import {
   ResponseConfig,
@@ -11,20 +11,19 @@ import { OpenAPIObjectConfig } from '@asteasolutions/zod-to-openapi/dist/v3.0/op
 import { HeadersObject as HeadersObject30 } from 'openapi3-ts/dist/model/openapi30'
 // @ts-ignore
 import { HeadersObject as HeadersObject31 } from 'openapi3-ts/dist/model/openapi31'
+import { OpenAPIRoute } from './route'
+import { OpenAPIRouterType } from './openapi'
 
 export interface RouterOptions {
   base?: string
-  routes?: RouteEntry[]
   schema?: Partial<OpenAPIObjectConfigV31 | OpenAPIObjectConfig>
   docs_url?: string
   redoc_url?: string
   openapi_url?: string
-  aiPlugin?: AIPlugin
   raiseUnknownParameters?: boolean
   generateOperationIds?: boolean
   openapiVersion?: '3' | '3.1'
   skipValidation?: boolean
-  baseRouter?: any
 }
 
 export declare type RouteParameter<Z extends z.ZodType = z.ZodType> = {
@@ -117,56 +116,6 @@ export interface RouteValidated {
   errors?: Record<string, any>
 }
 
-export enum SchemaVersion {
-  V1 = 'v1',
-}
-
-export enum AuthType {
-  NONE = 'none',
-  OAUTH = 'oauth',
-  SERVICE_HTTP = 'service_http',
-  USER_HTTP = 'user_http',
-}
-
-export enum APIType {
-  OPENAPI = 'openapi',
-}
-
-export interface AIPlugin {
-  schema_version?: SchemaVersion | string
-  name_for_model: string
-  name_for_human: string
-  description_for_model: string
-  description_for_human: string
-  auth?: Auth
-  api?: API
-  logo_url: string
-  contact_email: string
-  legal_info_url: string
-  is_dev?: boolean
-}
-
-export interface API {
-  type: APIType | string
-  url: string
-  has_user_authentication: boolean
-}
-
-export interface Auth {
-  type: AuthType | string
-  authorization_type?: string
-  authorization_url?: string
-  client_url?: string
-  scope?: string
-  authorization_content_type?: string
-  verification_tokens?: VerificationTokens
-  instructions?: string
-}
-
-export interface VerificationTokens {
-  openai: string
-}
-
 export type LegacyParameter<Z extends z.ZodType> = Z &
   (new (params?: ParameterType) => Z)
 
diff --git a/tests/integration/nested-routers.test.ts b/tests/integration/nested-routers.test.ts
index 0368175..9d73519 100644
--- a/tests/integration/nested-routers.test.ts
+++ b/tests/integration/nested-routers.test.ts
@@ -2,11 +2,15 @@ import 'isomorphic-fetch'
 
 import { OpenAPIRoute } from '../../src/route'
 import { Path } from '../../src/parameters'
-import { OpenAPIRouter } from '../../src/openapi'
+import { fromIttyRouter } from '../../src/openapi'
 import { buildRequest } from '../utils'
 import { jsonResp } from '../../src/utils'
+import { AutoRouter } from 'itty-router'
+
+const innerRouter = fromIttyRouter(AutoRouter({ base: '/api/v1' }), {
+  base: '/api/v1',
+})
 
-const innerRouter = OpenAPIRouter({ base: '/api/v1' })
 class ToDoGet extends OpenAPIRoute {
   static schema = {
     tags: ['ToDo'],
@@ -40,7 +44,7 @@ class ToDoGet extends OpenAPIRoute {
 innerRouter.get('/todo/:id', ToDoGet)
 innerRouter.all('*', () => jsonResp({ message: 'Not Found' }, { status: 404 }))
 
-const router = OpenAPIRouter({
+const router = fromIttyRouter(AutoRouter(), {
   schema: {
     info: {
       title: 'Radar Worker API',
@@ -54,7 +58,7 @@ router.all('*', () => new Response('Not Found.', { status: 404 }))
 
 describe('innerRouter', () => {
   it('simpleSuccessfulCall', async () => {
-    const request = await router.handle(
+    const request = await router.fetch(
       buildRequest({ method: 'GET', path: `/api/v1/todo/1` })
     )
     const resp = await request.json()
@@ -69,7 +73,7 @@ describe('innerRouter', () => {
   })
 
   it('innerCatchAll', async () => {
-    const request = await router.handle(
+    const request = await router.fetch(
       buildRequest({ method: 'GET', path: `/api/v1/asd` })
     )
     const resp = await request.json()
@@ -79,7 +83,7 @@ describe('innerRouter', () => {
   })
 
   it('outerCatchAll', async () => {
-    const request = await router.handle(
+    const request = await router.fetch(
       buildRequest({ method: 'GET', path: `/asd` })
     )
     const resp = await request.text()
diff --git a/tests/integration/openapi-schema.test.ts b/tests/integration/openapi-schema.test.ts
index 7e2442c..7a67f93 100644
--- a/tests/integration/openapi-schema.test.ts
+++ b/tests/integration/openapi-schema.test.ts
@@ -1,10 +1,12 @@
 import 'isomorphic-fetch'
 import { buildRequest, findError } from '../utils'
-import { ToDoList, todoRouter } from '../router'
+import { ToDoGet, ToDoList, todoRouter } from '../router'
+import { fromIttyRouter } from '../../src'
+import { AutoRouter } from 'itty-router'
 
 describe('openapi schema', () => {
   test('custom content type', async () => {
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: '/openapi.json' })
     )
     const resp = await request.json()
@@ -19,4 +21,18 @@ describe('openapi schema', () => {
       },
     })
   })
+
+  it('with base defined', async () => {
+    const router = fromIttyRouter(AutoRouter({ base: '/api' }), {
+      base: '/api',
+    })
+    router.get('/todo', ToDoGet)
+
+    const request = await router.fetch(
+      buildRequest({ method: 'GET', path: '/api/openapi.json' })
+    )
+    const resp = await request.json()
+
+    expect(Object.keys(resp.paths)[0]).toEqual('/api/todo')
+  })
 })
diff --git a/tests/integration/parameters.test.ts b/tests/integration/parameters.test.ts
index d24a6ba..2a02756 100644
--- a/tests/integration/parameters.test.ts
+++ b/tests/integration/parameters.test.ts
@@ -4,7 +4,7 @@ import { ToDoList, todoRouter } from '../router'
 
 describe('queryParametersValidation', () => {
   test('requiredFields', async () => {
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: '/todos' })
     )
     const resp = await request.json()
@@ -23,7 +23,7 @@ describe('queryParametersValidation', () => {
 
   test('checkNumberInvalid', async () => {
     const qs = '?p_number=asd'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -35,7 +35,7 @@ describe('queryParametersValidation', () => {
 
   test('checkNumberValidFloat', async () => {
     const qs = '?p_number=12.3'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -45,7 +45,7 @@ describe('queryParametersValidation', () => {
 
   test('checkNumberValidInteger', async () => {
     const qs = '?p_number=12'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -55,7 +55,7 @@ describe('queryParametersValidation', () => {
 
   test('checkStringValid', async () => {
     const qs = '?p_string=asd21_sa'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -65,7 +65,7 @@ describe('queryParametersValidation', () => {
 
   test('checkStringInvalidEmpty', async () => {
     const qs = '?p_string='
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -77,7 +77,7 @@ describe('queryParametersValidation', () => {
 
   test('checkBooleanInvalid', async () => {
     const qs = '?p_boolean=asd'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -89,7 +89,7 @@ describe('queryParametersValidation', () => {
 
   test('checkBooleanValid', async () => {
     const qs = '?p_boolean=false'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -99,7 +99,7 @@ describe('queryParametersValidation', () => {
 
   test('checkBooleanValidCaseInsensitive', async () => {
     const qs = '?p_boolean=TrUe'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -109,7 +109,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEnumerationSensitiveInvalid', async () => {
     const qs = '?p_enumeration=sfDase'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -121,7 +121,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEnumerationSensitiveInvalidCase', async () => {
     const qs = '?p_enumeration=Csv'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -133,7 +133,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEnumerationSensitiveValid', async () => {
     const qs = '?p_enumeration=csv'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -143,7 +143,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEnumerationInsensitiveInvalid', async () => {
     const qs = '?p_enumeration_insensitive=sfDase'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -155,7 +155,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEnumerationInsensitiveValidCase', async () => {
     const qs = '?p_enumeration_insensitive=Csv'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -165,7 +165,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEnumerationInsensitiveValid', async () => {
     const qs = '?p_enumeration_insensitive=csv'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -175,7 +175,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDatetimeInvalid', async () => {
     const qs = '?p_datetime=2023-13-01'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -187,7 +187,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDatetimeInvalid2', async () => {
     const qs = '?p_datetime=sdfg'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -199,7 +199,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDatetimeInvalid3', async () => {
     const qs = '?p_datetime=2022-09-15T00:00:00+01Z'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -211,7 +211,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDatetimeValid', async () => {
     const qs = '?p_datetime=2022-09-15T00:00:01Z'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -221,7 +221,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDatetimeValid2', async () => {
     const qs = '?p_datetime=2022-09-15T00:00:00Z'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -231,7 +231,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDateInvalid', async () => {
     const qs = '?p_dateonly=2022-13-15'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -241,7 +241,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDateInvalid3', async () => {
     const qs = '?p_dateonly=2022-09-15T00:0f0:00.0Z'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -251,7 +251,7 @@ describe('queryParametersValidation', () => {
 
   test('checkDateValid', async () => {
     const qs = '?p_dateonly=2022-09-15'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -261,7 +261,7 @@ describe('queryParametersValidation', () => {
 
   test('checkRegexInvalid', async () => {
     const qs = '?p_regex=123765'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -271,7 +271,7 @@ describe('queryParametersValidation', () => {
 
   test('checkRegexValid', async () => {
     const qs = '?p_regex=%2B919367788755'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -281,7 +281,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEmailInvalid', async () => {
     const qs = '?p_email=asfdgsdf'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -291,7 +291,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEmailInvalid2', async () => {
     const qs = '?p_email=asfdgsdf@gmail'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -301,7 +301,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEmailInvalid3', async () => {
     const qs = '?p_email=@gmail.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -311,7 +311,7 @@ describe('queryParametersValidation', () => {
 
   test('checkEmailValid', async () => {
     const qs = '?p_email=sdfg@gmail.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -321,7 +321,7 @@ describe('queryParametersValidation', () => {
 
   test('checkUuidInvalid', async () => {
     const qs = '?p_uuid=f31f890-044b-11ee-be56-0242ac120002'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -331,7 +331,7 @@ describe('queryParametersValidation', () => {
 
   test('checkUuidInvalid2', async () => {
     const qs = '?p_uuid=asdf-sdfg-dsfg-sfdg'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -341,7 +341,7 @@ describe('queryParametersValidation', () => {
 
   test('checkUuidValid', async () => {
     const qs = '?p_uuid=f31f8b90-044b-11ee-be56-0242ac120002'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -351,7 +351,7 @@ describe('queryParametersValidation', () => {
 
   test('checkUuidValid2', async () => {
     const qs = '?p_uuid=f5f26194-0b07-45a4-9a85-94d3db01e7a5'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -361,7 +361,7 @@ describe('queryParametersValidation', () => {
 
   test('checkHostnameInvalid', async () => {
     const qs = '?p_hostname=.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -371,7 +371,7 @@ describe('queryParametersValidation', () => {
 
   test('checkHostnameValid', async () => {
     const qs = '?p_hostname=cloudflare.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -381,7 +381,7 @@ describe('queryParametersValidation', () => {
 
   test('checkHostnameValid2', async () => {
     const qs = '?p_hostname=radar.cloudflare.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -391,7 +391,7 @@ describe('queryParametersValidation', () => {
 
   test('checkIpv4Invalid', async () => {
     const qs = '?p_ipv4=asdfrre.wer.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -401,7 +401,7 @@ describe('queryParametersValidation', () => {
 
   test('checkIpv4Invalid2', async () => {
     const qs = '?p_ipv4=2001:0db8:85a3:0000:0000:8a2e:0370:7334'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -411,7 +411,7 @@ describe('queryParametersValidation', () => {
 
   test('checkIpv4Valid', async () => {
     const qs = '?p_ipv4=1.1.1.1'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -421,7 +421,7 @@ describe('queryParametersValidation', () => {
 
   test('checkIpv6Invalid', async () => {
     const qs = '?p_ipv6=asdfrre.wer.com'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -431,7 +431,7 @@ describe('queryParametersValidation', () => {
 
   test('checkIpv6Invalid2', async () => {
     const qs = '?p_ipv6=1.1.1.1'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -441,7 +441,7 @@ describe('queryParametersValidation', () => {
 
   test('checkIpv6Valid', async () => {
     const qs = '?p_ipv6=2001:0db8:85a3:0000:0000:8a2e:0370:7336'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -451,7 +451,7 @@ describe('queryParametersValidation', () => {
 
   test('checkOptionalMissing', async () => {
     const qs = '?'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -461,7 +461,7 @@ describe('queryParametersValidation', () => {
 
   test('checkOptionalInvalid', async () => {
     const qs = '?p_optional=asfdasd'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -473,7 +473,7 @@ describe('queryParametersValidation', () => {
 
   test('checkOptionalValid', async () => {
     const qs = '?p_optional=32'
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({ method: 'GET', path: `/todos${qs}` })
     )
     const resp = await request.json()
@@ -484,7 +484,7 @@ describe('queryParametersValidation', () => {
 
 describe('bodyParametersValidation', () => {
   test('requiredFieldTitle', async () => {
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({
         method: 'POST',
         path: '/todos',
@@ -502,7 +502,7 @@ describe('bodyParametersValidation', () => {
   })
 
   test('requiredFieldTipe', async () => {
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({
         method: 'POST',
         path: '/todos',
@@ -522,7 +522,7 @@ describe('bodyParametersValidation', () => {
   })
 
   test('validRequest', async () => {
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({
         method: 'POST',
         path: '/todos',
@@ -546,7 +546,7 @@ describe('bodyParametersValidation', () => {
   })
 
   test('validRequestWithOptionalParameters', async () => {
-    const request = await todoRouter.handle(
+    const request = await todoRouter.fetch(
       buildRequest({
         method: 'POST',
         path: '/todos',
diff --git a/tests/integration/router-options.test.ts b/tests/integration/router-options.test.ts
index 0190b6a..b31619c 100644
--- a/tests/integration/router-options.test.ts
+++ b/tests/integration/router-options.test.ts
@@ -1,9 +1,9 @@
 import 'isomorphic-fetch'
 
 import { OpenAPIRoute } from '../../src/route'
-import { OpenAPIRouter } from '../../src/openapi'
 import { buildRequest } from '../utils'
-import { OpenAPIRouteSchema } from '../../src'
+import { fromIttyRouter, OpenAPIRouteSchema } from '../../src'
+import { AutoRouter } from 'itty-router'
 
 class EndpointWithoutOperationId extends OpenAPIRoute {
   static schema = {
@@ -35,7 +35,7 @@ class EndpointWithOperationId extends OpenAPIRoute {
 describe('routerOptions', () => {
   it('generate operation ids false', async () => {
     const t = () => {
-      const router = OpenAPIRouter({
+      const router = fromIttyRouter(AutoRouter(), {
         generateOperationIds: false,
       })
       router.get('/todo', EndpointWithoutOperationId)
@@ -45,7 +45,7 @@ describe('routerOptions', () => {
   })
 
   it('generate operation ids true and unset', async () => {
-    const routerTrue = OpenAPIRouter({
+    const routerTrue = fromIttyRouter(AutoRouter(), {
       generateOperationIds: true,
     })
     routerTrue.get('/todo', EndpointWithoutOperationId)
@@ -62,7 +62,7 @@ describe('routerOptions', () => {
       throw new Error('/todo not found in schema')
     }
 
-    const routerUnset = OpenAPIRouter()
+    const routerUnset = fromIttyRouter(AutoRouter())
     routerUnset.get('/todo', EndpointWithoutOperationId)
 
     if (
@@ -79,7 +79,7 @@ describe('routerOptions', () => {
   })
 
   it('generate operation ids true on endpoint with operation id', async () => {
-    const router = OpenAPIRouter({
+    const router = fromIttyRouter(AutoRouter(), {
       generateOperationIds: true,
     })
     router.get('/todo', EndpointWithOperationId)
@@ -98,10 +98,10 @@ describe('routerOptions', () => {
   })
 
   it('with base empty', async () => {
-    const router = OpenAPIRouter()
+    const router = fromIttyRouter(AutoRouter())
     router.get('/todo', EndpointWithOperationId)
 
-    const request = await router.handle(
+    const request = await router.fetch(
       buildRequest({ method: 'GET', path: '/todo' })
     )
     const resp = await request.json()
@@ -110,10 +110,12 @@ describe('routerOptions', () => {
   })
 
   it('with base defined', async () => {
-    const router = OpenAPIRouter({ base: '/api' })
+    const router = fromIttyRouter(AutoRouter({ base: '/api' }), {
+      base: '/api',
+    })
     router.get('/todo', EndpointWithOperationId)
 
-    const request = await router.handle(
+    const request = await router.fetch(
       buildRequest({ method: 'GET', path: '/api/todo' })
     )
     const resp = await request.json()
diff --git a/tests/integration/zod.ts b/tests/integration/zod.ts
index 8fd26a4..292cbfe 100644
--- a/tests/integration/zod.ts
+++ b/tests/integration/zod.ts
@@ -2,11 +2,12 @@ import 'isomorphic-fetch'
 
 import { OpenAPIRoute } from '../../src/route'
 import { Path } from '../../src/parameters'
-import { OpenAPIRouter } from '../../src/openapi'
+import { fromIttyRouter } from '../../src/openapi'
 import { buildRequest } from '../utils'
 import { z } from 'zod'
+import { AutoRouter } from 'itty-router'
 
-const zodRouter = OpenAPIRouter()
+const zodRouter = fromIttyRouter(AutoRouter())
 
 class ToDoGet extends OpenAPIRoute {
   static schema = {
@@ -50,7 +51,7 @@ zodRouter.put('/todo/:id', ToDoGet)
 
 describe('zod validations', () => {
   it('simpleSuccessfulCall', async () => {
-    const request = await zodRouter.handle(
+    const request = await zodRouter.fetch(
       buildRequest({ method: 'PUT', path: `/todo/1` })
     )
 
diff --git a/tests/router.ts b/tests/router.ts
index 81db03c..1ab920e 100644
--- a/tests/router.ts
+++ b/tests/router.ts
@@ -1,4 +1,4 @@
-import { OpenAPIRouter } from '../src/openapi'
+import { fromIttyRouter } from '../src/openapi'
 import { OpenAPIRoute } from '../src/route'
 import {
   Bool,
@@ -6,20 +6,21 @@ import {
   DateTime,
   Email,
   Enumeration,
+  Header,
   Hostname,
   Int,
   Ipv4,
   Ipv6,
   Num,
+  Path,
   Query,
   Regex,
   Str,
   Uuid,
-  Path,
-  Header,
 } from '../src/parameters'
-import { OpenAPIRouteSchema, DataOf } from '../src'
+import { DataOf, OpenAPIRouteSchema } from '../src'
 import { z } from 'zod'
+import { AutoRouter } from 'itty-router'
 
 export class ToDoList extends OpenAPIRoute {
   static schema = {
@@ -243,7 +244,7 @@ export class ToDoCreateTyped extends OpenAPIRoute {
   }
 }
 
-export const todoRouter = OpenAPIRouter({ openapiVersion: '3' })
+export const todoRouter = fromIttyRouter(AutoRouter(), { openapiVersion: '3' })
 todoRouter.get('/todos', ToDoList)
 todoRouter.get('/todos/:id', ToDoGet)
 todoRouter.post('/todos', ToDoCreate)