diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..36dd944
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,252 @@
+import type { IRouter, Request, RequestHandler as Middleware, Response, NextFunction } from "express";
+import type { OpenAPIV3 } from "openapi-types";
+import type { SwaggerUIOptions } from "swagger-ui";
+
+type Options = {
+  basePath?: string;
+  htmlui?: "swagger-ui";
+  coerce?: "true" | "false";
+};
+
+interface OpenApiMiddleware extends Middleware {
+  document: OpenAPIV3.Document;
+  options: Options;
+  routePrefix: string;
+  generateDocument: (doc: OpenAPIV3.Document, router?: IRouter, basePath?: string) => OpenAPIV3.Document;
+  /**
+   * Registers a path with the OpenAPI document.
+   * The path `definition` is an {@link https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#operationObject OperationObject}
+   * with all of the information about the requests and responses on that route.
+   *
+   * It returns a middleware function which can be used in an express app.
+   *
+   * @example
+   *
+   * ```ts
+   * app.get('/:foo', oapi.path({
+   *   description: 'Get a foo',
+   *   responses: {
+   *     200: {
+   *       content: {
+   *         'application/json': {
+   *           schema: {
+   *             type: 'object',
+   *             properties: {
+   *               foo: { type: 'string' }
+   *             }
+   *           }
+   *         }
+   *       }
+   *     }
+   *   }
+   * }), (req, res) => {
+   *  res.json({
+   *    foo: req.params.foo
+   *  })
+   * })
+   * ```
+   */
+  path: (schema?: OpenAPIV3.OperationObject) => Middleware;
+  /**
+   * Registers a path with the OpenAPI document, also ensures incoming requests are valid against the schema.
+   * The path `definition` is an {@link https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#operationObject OperationObject}
+   * with all of the information about the requests and responses on that route.
+   *
+   * It returns a middleware function which can be used in an express app and will call `next(err)` if the incoming request is invalid.
+   * The error is created with ({@link https://www.npmjs.com/package/http-errors http-errors}), and then is augmented with information about the schema and validation errors.
+   * Validation uses ({@link https://www.npmjs.com/package/ajv ajv}), and `err.validationErrors` is the format exposed by that package.
+   *
+   * Pass `{ keywords: [] }` as `pathOpts` to support custom validation based on ajv-keywords.
+   *
+   * @example
+   * ```js
+   * app.get('/:foo', oapi.validPath({
+   *   description: 'Get a foo',
+   *   responses: {
+   *     200: {
+   *       content: {
+   *         'application/json': {
+   *           schema: {
+   *             type: 'object',
+   *             properties: {
+   *               foo: { type: 'string' }
+   *             }
+   *           }
+   *         }
+   *       }
+   *     },
+   *     400: {
+   *       content: {
+   *         'application/json': {
+   *           schema: {
+   *             type: 'object',
+   *             properties: {
+   *               error: { type: 'string' }
+   *             }
+   *           }
+   *         }
+   *       }
+   *     }
+   *   }
+   * }), (err, req, res, next) => {
+   *   res.status(err.status).json({
+   *     error: err.message,
+   *     validation: err.validationErrors,
+   *     schema: err.validationSchema
+   *   })
+   * })
+   *
+   * app.get('/zoom', oapi.validPath({
+   *   ...
+   *   requestBody: {
+   *     required: true,
+   *     content: {
+   *       'application/json': {
+   *         schema: {
+   *           type: 'object',
+   *           properties: {
+   *             name: { type: 'string', not: { regexp: '/^[A-Z]/' } }
+   *           }
+   *         }
+   *       }
+   *     }
+   *   },
+   *   ...
+   * }, { keywords: ['regexp'] }), (err, req, res, next) => {
+   *   res.status(err.status).json({
+   *     error: err.message,
+   *     validation: err.validationErrors,
+   *     schema: err.validationSchema
+   *   })
+   * })
+   * ```
+   */
+  validPath: (schema?: OpenAPIV3.OperationObject, pathOpts?: { strict?: boolan; keywords?: string | string[] }) => Middleware;
+  /**
+   * Defines a new {@link https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#components-object Component} on the document.
+   *
+   * @example
+   * ```js
+   * oapi.component('examples', 'FooExample', {
+   *   summary: 'An example of foo',
+   *   value: 'bar'
+   * })
+   * ```
+   *
+   * If `name` is defined but `definition` is not, it will return a {@link https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#referenceObject Reference Object} pointing to the component by that name.
+   *
+   * @example
+   * ```js
+   * oapi.component('examples', 'FooExample')
+   * // { '$ref': '#/components/examples/FooExample' }
+   * ```
+   *
+   * If neither `definition` nor `name` are passed, the function will return the full `components` json.
+   *
+   * @example
+   * ```js
+   * oapi.component('examples')
+   * // { summary: 'An example of foo', value: 'bar' }
+   * ```
+   */
+  component: {
+    <Type extends keyof Component>(type: Type): OpenAPIV3.ComponentsObject[Type];
+    <Type extends keyof Component>(type: Type, name: string): OpenAPIV3.ReferenceObject;
+    <Type extends keyof Component>(type: Type, name: string, definition: Component[Type]): OpenApiMiddleware;
+  };
+  schema: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.SchemaObject): OpenApiMiddleware;
+  };
+  response: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.ResponseObject): OpenApiMiddleware;
+  };
+  parameters: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.ParameterObject): OpenApiMiddleware;
+  };
+  examples: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.ExampleObject): OpenApiMiddleware;
+  };
+  requestBodies: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.RequestBodyObject): OpenApiMiddleware;
+  };
+  headers: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.HeaderObject): OpenApiMiddleware;
+  };
+  securitySchemes: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.SecuritySchemeObject): OpenApiMiddleware;
+  };
+  links: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.LinkObject): OpenApiMiddleware;
+  };
+  callbacks: {
+    (name: string): OpenAPIV3.ReferenceObject;
+    (name: string, definition: OpenAPIV3.CallbackObject): OpenApiMiddleware;
+  };
+  /**
+   * Serve an interactive UI for exploring the OpenAPI document.
+   *
+   * {@link https://www.npmjs.com/package/swagger-ui SwaggerUI} is one of the most popular tools for viewing OpenAPI documents and are bundled with the middleware.
+   * The UI is not turned on by default but can be with the option mentioned above or by using one of these middleware.
+   * Both interactive UIs also accept an optional object as a function argument which accepts configuration parameters for Swagger and Redoc.
+   * The full list of Swagger and Redoc configuration options can be found {@link https://swagger.io/docs/open-source-tools/swagger-ui/usage/configuration/ here} 
+   * and {@link https://redocly.com/docs/redoc/config/ here} respectively.
+   *
+   * @example
+   * ```js
+   * app.use('/swaggerui', oapi.swaggerui())
+   * ```
+   */
+  swaggerui: (options?: SwaggerUIOptions) => Middleware[];
+}
+
+/** 
+ * Utility type helper to return value types from the given Record type `T`.
+ */
+type ObjectValue<T extends Record<string, unknown>> = T extends { [key: string]: infer V } ? V : never;
+
+/**
+ * Utility type helper to compose a map of `OpenAPIV3.ComponentsObject`.
+ *
+ * This map type is used to determine what type we are allowed to input or
+ * expected to return from the {@link OpenApiMiddleware.component} function.
+ */
+type Component = {
+  [K in keyof OpenAPIV3.ComponentsObject]-?: ObjectValue<OpenAPIV3.ComponentsObject[K]>;
+};
+
+/**
+ * Creates an instance of the documentation middleware.
+ * The function that is returned is a middleware function decorated with helper methods for setting up the api documentation.
+ *
+ * @param route - A route for which the documentation will be served at
+ * @param doc - Base document on top of which the paths will be added
+ * @param options - Options
+ * @param options.coerce - Enable data type {@link https://www.npmjs.com/package/ajv#coercing-data-types coercion}
+ * @param options.htmlui - Turn on serving `swagger-ui` html ui
+ * @param options.basePath - When set, will strip the value of `basePath` from the start of every path
+ *
+ * Coerce 
+ *
+ * By default `coerceTypes` is set to `true` for `ajv`, but a copy of the `req` data is passed to prevent modifying the `req` in an unexpected way.
+ * This is because the `coerceTypes` option in ({@link https://github.com/ajv-validator/ajv/issues/549 `ajv` modifies the input}).
+ * If this is the behavior you want, you can pass `true` for this and a copy will not be made.
+ * This will result in params in the path or query with type `number` will be converted to numbers {@link https://github.com/epoberezkin/ajv/blob/master/COERCION.md based on the rules from `ajv`}.
+ */
+function openapi(): OpenApiMiddleware;
+function openapi(doc: OpenAPIV3.Document, opts?: Options): OpenApiMiddleware;
+function openapi(route: string, doc?: OpenAPIV3.Document, opts?: Options): OpenApiMiddleware;
+
+namespace openapi {
+  const minimumViableDocument: OpenAPIV3.Document;
+  const defaultRoutePrefix: "/openapi";
+}
+
+export = openapi;
diff --git a/package.json b/package.json
index 5b0b0f9..7276840 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,7 @@
   ],
   "license": "ISC",
   "main": "index.js",
+  "types": "index.d.ts",
   "repository": {
     "type": "git",
     "url": "wesleytodd/express-openapi"
@@ -29,11 +30,14 @@
     "supertest": "^6.3.4"
   },
   "dependencies": {
+    "@types/express": "^4.17.21",
+    "@types/swagger-ui": "^3.52.4",
     "ajv": "^8.12.0",
     "ajv-formats": "^2.1.1",
     "ajv-keywords": "^5.1.0",
     "http-errors": "^2.0.0",
     "merge-deep": "^3.0.3",
+    "openapi-types": "^12.1.3",
     "path-to-regexp": "^6.2.1",
     "router": "^1.3.8",
     "serve-static": "^1.15.0",
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..f9b9187
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "$schema": "https://json.schemastore.org/tsconfig",
+  "compilerOptions": {
+    "target": "es2016",
+    "module": "commonjs",
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "skipLibCheck": true
+  }
+}