Hey API

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

About

Hey API is an ecosystem for turning API specifications into production-ready code. It's trusted by thousands of companies – from YC startups to Fortune 500 enterprises – and powers products used by millions worldwide.

This is the monorepo containing all open source Hey API packages. For package-specific documentation and quick start guides, see the individual repositories below.

Packages

Package	Description
`openapi-ts`	TypeScript code generator with 20+ plugins for SDKs, Zod schemas, TanStack Query hooks, and more. Manual • npm
`openapi-python`	Python code generator for SDKs and Pydantic models. Manual • npm

Highlights

production-grade code that compiles
runs in any Node.js 22+ environment
accepts any OpenAPI specification
core plugins for SDKs
HTTP clients for Fetch API, Axios, Angular, Next.js, Nuxt, HTTPX, and more
Zod schemas, TanStack Query hooks, Pydantic models, and 20+ plugins to reduce third-party boilerplate
highly customizable via plugins