Hono Zod OpenAPI Middleware

hono-zod-openapi is a middleware library for the Hono web framework that generates OpenAPI documentation directly from Zod schemas, offering a type-safe approach to API definition. Unlike some alternative solutions, it integrates as a standard Hono middleware, avoiding the need for significant refactoring of existing Hono applications. The current stable version is 1.1.1, released in February 2026. The project maintains an active release cadence, with frequent minor updates and bug fixes. Its key differentiator is the non-intrusive middleware pattern for OpenAPI definition, making it easy to adopt in existing Hono projects, along with providing a `createOpenApiDocument` function to serve the generated documentation.