OpenAPI TypeScript

“OpenAPI codegen that just works.”
_{— Guillermo Rauch, CEO of Vercel}

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The OpenAPI to TypeScript code generator used by Vercel, OpenCode, and PayPal.

Generate production-ready SDKs, Zod schemas, TanStack Query hooks, or choose from 20+ other plugins.

Part of the Hey API ecosystem.

• production-ready code that compiles
• runs in any Node.js 20+ environment
• accepts any OpenAPI specification
• core plugins for SDKs, types, and schemas
• HTTP clients for Fetch API, Angular, Axios, Next.js, Nuxt, and more
• 20+ plugins to reduce third-party boilerplate
• highly customizable via plugins
• sync with Hey API Registry for spec management

Want to see your code in products used by millions?

Start with our Contributing guide and release your first feature.

Hey API is sponsor-funded. If your team relies on Hey API in production, consider becoming a sponsor to accelerate the roadmap.

scalar.com

fastapi.tiangolo.com

The fastest way to use @hey-api/openapi-ts is via npx

npx @hey-api/openapi-ts -i hey-api/backend -o src/client

Congratulations on creating your first client! 🎉 You can learn more about the generated files on the Output page.

You can download @hey-api/openapi-ts from npm using your favorite package manager.

npm install @hey-api/openapi-ts -D -E

pnpm add @hey-api/openapi-ts -D -E

yarn add @hey-api/openapi-ts -D -E

bun add @hey-api/openapi-ts -D -E

This package does NOT follow the semantic versioning strategy. Please pin an exact version so you can safely upgrade when you're ready.

Due to the nature of the package, we use the following versioning strategy.

• 1.x.x: significant breaking changes, reserved for v1 release
• x.1.x: breaking changes
• x.x.1: new features, bug fixes, and non-breaking changes

We publish migration notes for every breaking release. You might not be impacted by a breaking release if you don't use the affected plugin(s).

Most people run @hey-api/openapi-ts via CLI. To do that, add a script to your package.json file which will make openapi-ts executable through script.

"scripts": {
  "openapi-ts": "openapi-ts"
}

The above script can be executed by running npm run openapi-ts or equivalent command in other package managers. Next, we will create a configuration file and move our options from Quick Start to it.

You can also generate output programmatically by calling createClient() in a JavaScript/TypeScript file.

import { createClient } from '@hey-api/openapi-ts';
createClient({
  input: 'hey-api/backend', // sign up at app.heyapi.dev
  output: 'src/client',
});

@hey-api/openapi-ts supports loading configuration from any file inside your project root folder supported by jiti loader. Below are the most common file formats.

import { defineConfig } from '@hey-api/openapi-ts';
export default defineConfig({
  input: 'hey-api/backend', // sign up at app.heyapi.dev
  output: 'src/client',
});

/** @type {import('@hey-api/openapi-ts').UserConfig} */
module.exports = {
  input: 'hey-api/backend', // sign up at app.heyapi.dev
  output: 'src/client',
};

/** @type {import('@hey-api/openapi-ts').UserConfig} */
export default {
  input: 'hey-api/backend', // sign up at app.heyapi.dev
  output: 'src/client',
};

Alternatively, you can use openapi-ts.config.js and configure the export statement depending on your project setup.

You must set the input so we can load your OpenAPI specification. It can be a path or URL, object containing a path or URL, or an object representing an OpenAPI specification. Hey API supports all valid OpenAPI versions and file formats.

If you use an HTTPS URL with a self-signed certificate in development, you will need to set NODE_TLS_REJECT_UNAUTHORIZED=0 in your environment.

You must set the output so we know where to generate your files. It can be a path to the destination folder or an object containing the destination folder path and optional settings.

You should treat the output folder as a dependency. Do not directly modify its contents as your changes might be erased when you run @hey-api/openapi-ts again.

We parse your input before making it available to plugins. While configuring the parser is optional, it's the perfect place to modify or validate your input if needed.

Plugins are responsible for generating artifacts from your input. By default, Hey API will generate TypeScript interfaces and SDK from your OpenAPI specification. You can add, remove, or customize any of the plugins. In fact, we highly encourage you to do so!

Clients are responsible for sending the actual HTTP requests. Using clients is not required, but you must add a client to plugins if you're generating SDKs (we default to Fetch).

• @hey-api/client-fetch
• @hey-api/client-angular
• @hey-api/client-axios
• @hey-api/client-ky
• @hey-api/client-next
• @hey-api/client-nuxt
• @hey-api/client-ofetch

The following clients are planned but not in development yet. You can help us prioritize them by voting on GitHub.

• @hey-api/client-effect

Don't see your client? Build your own or let us know your interest by opening an issue.

These plugins help reduce boilerplate associated with third-party dependencies. Hey API natively supports the most popular packages. Please open an issue on GitHub if you'd like us to support your favorite package.

• @angular/common
• @hey-api/schemas
• @hey-api/sdk
• @hey-api/transformers
• @hey-api/typescript
• @pinia/colada
• @tanstack/angular-query-experimental
• @tanstack/react-query
• @tanstack/solid-query
• @tanstack/svelte-query
• @tanstack/vue-query
• fastify
• valibot
• zod

The following plugins are planned but not in development yet. You can help us prioritize them by voting on GitHub.

• Adonis
• Ajv
• Arktype
• Chance
• Elysia
• Express
• Faker
• Falso
• Hono
• Joi
• Koa
• MSW
• Nest
• Nock
• Superstruct
• Supertest
• SWR
• TypeBox
• Yup
• Zustand

Don't see your plugin? Build your own or let us know your interest by opening an issue.

You can learn more on the Migrating page.

Released under the MIT License.