Getting zod schema from client or contract

[ryantsangai]

I am working on contract first approach with OpenAPI handler.
It is a mono repo which have API contract , backend and frontend separately.

In frontend, is there anyway I can get the input schema (zod) so that I can use it in react-hook-form?
I've tried to get it from contract and client instance. But seems there are no property is suitable for such case

[dosubot[bot]]

Hi @ryantsangai! I'm Dosu and I’m helping the orpc team.

You can't get the Zod schema from the client instance or from the contract JSON in the frontend—this is by design. Zod schemas are not serializable, so when you export your contract (for example, using minifyContractRouter), the schemas are stripped out and only routing/metadata is kept. The OpenAPI spec JSON includes schemas, but they're in JSON Schema format, not Zod, so you can't use them directly with react-hook-form either reference.

The recommended way in a monorepo is to define your Zod schemas in a shared contract package and import them directly in both backend and frontend. That way, you can use the exact same schema for both API validation and react-hook-form integration reference.

Example:

// shared/contract.ts
import { z } from "zod";
export const CreatePostSchema = z.object({
  title: z.string(),
  content: z.string(),
});

// apps/frontend/CreatePostForm.tsx
import { useForm } from "react-hook-form";
import { zodResolver } from "@hookform/resolvers/zod";
import { CreatePostSchema } from "@workspace/contract";

const form = useForm({
  resolver: zodResolver(CreatePostSchema),
  defaultValues: { title: "", content: "" },
});

If you can't use a shared package, you'd need to duplicate the schema or convert JSON Schema back to Zod (which is non-trivial and lossy). But in a monorepo, sharing the schema module is the best practice reference.

To reply, just mention @dosu.

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[unnoq]

Maybe this can help procedure['~orpc'].inputSchema

[ryantsangai]

I tried, but it show "Invalid input: not a Zod schema"
I tried to console.log, but client is proxy object

You may check with the demo on stackblitz
https://stackblitz.com/edit/vitejs-vite-e3tb6dsp?file=package.json,src%2FApp.tsx,src%2Fclient.ts&terminal=dev

[unnoq]

contract not client

[ryantsangai]

it work!
Thanks a lot