Guide
A common question: can Zod schemas be turned into an OpenAPI document? Yes — with a dedicated library. This page is factual about what those libraries do, how they differ from Docloom, and which one fits your goal. Docloom is not an OpenAPI generator.
| Docloom | Zod-to-OpenAPI libraries | |
|---|---|---|
| Goal | A readable API reference for developers, kept in step with the code. | A machine-readable OpenAPI 3 document. |
| Input | Next.js route handlers plus their Zod schemas, parsed with the TypeScript compiler. | Your Zod schemas, registered with the library's registry/extension API. |
| Output | A hosted markdown reference: endpoints, bodies, responses, query and header inputs. | An OpenAPI 3 document (JSON or YAML). |
| Where Zod sits | Detected on your routes (same file, plus one import hop). | Each schema is registered explicitly with the generator. |
| Consumers | People reading API docs. | SDK generators, gateways, mock servers, Swagger UI and ReDoc. |
| Gaps | Unresolvable fields render as “not documented in source”. | Unregistered schemas simply do not appear in the spec. |
Libraries such as @asteasolutions/zod-to-openapi and zod-openapi take Zod schemas and emit an OpenAPI document. They ask you to register each schema and attach OpenAPI metadata — paths, methods, response codes — to it. That produces a precise, machine-readable spec, which is exactly what you want when you need code generation or gateway support.
Docloom reads your Next.js App Router route handlers with the TypeScript compiler, resolves the Zod schemas they use, and writes a human-readable API reference over those facts. It does not emit OpenAPI, and it is explicit about that difference.
If you need OpenAPI for machine consumers, use a Zod-to-OpenAPI library. If you need a reference that tracks your handlers without hand-maintained schema registrations, Docloom is built for that. Teams that need both routinely run both — an OpenAPI document for tooling, a generated reference for people.
Paste a public GitHub repo and get the same AST-verified API reference the product produces. No account, no persistence, about a minute.
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