Hey API
An ecosystem of code generators that turn OpenAPI specifications into production-ready TypeScript or Python SDKs, along with validators, mocks, and other client code.
Hey API is a monorepo of open-source packages that generate SDKs from OpenAPI specifications. Its openapi-ts package generates TypeScript code with more than 20 plugins for SDKs, Zod schemas, TanStack Query hooks, and other client code, while openapi-python generates Python SDKs and Pydantic models.
Generated code runs in any Node.js 22 or later environment, accepts any OpenAPI specification, and can target HTTP clients such as Fetch, Axios, Angular, Next.js, Nuxt, or HTTPX. A separate spec-types package provides TypeScript definitions for OpenAPI and JSON Schema specifications with inline documentation.
It is written in TypeScript and released under the MIT license.