Overview

Stratal generates a complete OpenAPI 3.0 specification from the Zod schemas you already use for validation. One schema drives both runtime validation and your API documentation, so the two can never drift apart.

What you get

Every @Route-decorated controller method is automatically included in a generated OpenAPI spec. The OpenAPIModule is registered as core infrastructure during application startup, so there is nothing to set up for basic usage.

Tip

If your controllers already use @Route with Zod schemas, you have OpenAPI documentation. No additional annotations are required.

Out of the box, you get:

• Automatic OpenAPI 3.0 spec generated from your Zod schemas and route decorators.
• Interactive API docs served by Swagger UI at /api/docs.
• JSON spec endpoint at /api/openapi.json for importing into tools like Postman or Insomnia.
• Built-in security scheme definitions for bearer tokens, API keys, and session cookies.
• Common error responses (400, 401, 403, 404, 409, 500) auto-included on every route.
• Unreferenced schema pruning so the spec only contains schemas your routes actually use.

How it works

The flow from code to interactive docs looks like this:

1. You define Zod schemas and attach them to controller methods via the @Route decorator.
2. At startup, Stratal registers each route with @hono/zod-openapi, which builds the full OpenAPI document.
3. When a request hits the JSON spec endpoint, Stratal filters out hidden routes, prunes unused schemas, and returns the final spec.
4. The docs UI reads that spec and renders an interactive API reference.

Note

The generated specification follows OpenAPI 3.0.0. Stratal uses Hono’s OpenAPI integration under the hood, so any tooling that supports OpenAPI 3.0 will work with the generated spec.

Next steps

Head to Setup to learn how to customize the OpenAPI spec metadata, paths, and security schemes.