# What changed in @hono/zod-openapi

> 4 changes in @hono/zod-openapi 1 from its official release notes, upgrade guides and advisories: 1 breaking. Each one cited. Sources checked 2026-10-24. HTML: https://unstale.sh/npm/@hono/zod-openapi/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## @hono/zod-openapi 1

### Breaking changes

- JSON or form requests whose Content-Type matches none of the route's declared media types now return 415 instead of validating an empty object. (1.6.3) — [release notes](https://github.com/honojs/middleware/releases/tag/%40hono/zod-openapi%401.6.3)

### Performance

- Projected response types are reused between route handlers and returned schemas to reduce TypeScript checker work. (1.6.2) — [release notes](https://github.com/honojs/middleware/releases/tag/%40hono/zod-openapi%401.6.2)

### Fixes and other changes

- The handler now infers the route middleware environment. (1.6.2) — [release notes](https://github.com/honojs/middleware/releases/tag/%40hono/zod-openapi%401.6.2)
- Batched route type inference is flattened so large openapiRoutes tuples do not hit TypeScript's recursive instantiation limit. (1.6.2) — [release notes](https://github.com/honojs/middleware/releases/tag/%40hono/zod-openapi%401.6.2)