feat: support Zod 4

[colinhacks]

Per some discussions I've been having with @bluebill1049, this PR adds support for Zod 4.

The other PR by @alexcraviotto (#776) is really solid but we decided to go another direction.

• This PR bumps the minimum Zod version to 3.25.0
• With this change, it;s possible to support both Zod 3 and Zod 4 in a single zodResolver (via Zod's subpath versioning scheme)
• I've designed this to continue working with Zod versions pre-3.25.0, but it's on a best-effort basis. For instance, you won't get perfect type signatures on parse params (the second argument to zodResolver). There were zero breaking changes between Zod 3.24 and Zod 3.25 so there's no reason not to upgrade.

Both Zod 3 and Zod 4 schemas can be passed into zodResolver():

import { zodResolver } from "@hookform/resolvers";
import * as z3 from "zod/v3"; // or just "zod"
import * as z4 from "zod/v4";

const oldResolver = zodResolver(z3.object({ name: z.string() }));
const newResolver = zodResolver(z4.object({ name: z.string() }));

[bluebill1049]

LGTM

[jorisre]

Thanks for the black TypeScript magic 🧙‍♂️ Really appreciate you jumping in and helping out with this. Everything looks solid and comes with a good DX too 🙌

[github-actions]

🎉 This PR is included in version 5.1.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[alexcraviotto]

Amazing!

[lucadenardi-sinesy]

Hello, I'm trying to use react-hook-form with zod/v4.
It seems to me that this code should work, yet I'm facing an issue about incompatible types between the one expected by zodResolver and the passed schema.

//"react-hook-form": "^7.57.0",
import { useForm } from "react-hook-form";

//"@hookform/resolvers": "^5.1.0",
import { zodResolver } from "@hookform/resolvers/zod";

//"zod": "^3.25.57",
import { z } from "zod/v4";

const loginSchema = z.object({
	email: z.email("email.invalid"),
	password: z
		.string()
		.nonempty("password.required")
		.min(8, "password.minLength"),
});
export const Component = (): void => {
	useForm({
		resolver: zodResolver(loginSchema),
		mode: "onChange",
		defaultValues: {
			email: "",
			password: "",
		},
	});
};

Does anyone have any idea of why this happens?
Thanks

[MartinCura]

(...)

Does anyone have any idea of why this happens? Thanks

Found the same thing, not sure why. I switched to using the standardSchemaResolver and it seems to work so i worked around it 🤷🏼 Not sure if you found the reason.

[sergiojoker11]

Backwards compatibility got broken with this change. In reality, this has been a 'feat!'
The type Zod3Type introduced by this PR is incompatible with ZodType from zod lib-pre-upgrade.