@kamod-ch/otok-validation

Standard Schema validation for Otok — typed inputs, field/form errors, and defineAction integration. Works with Zod, Valibot, and ArkType without forcing a schema library in Otok core.

defineAction with schema

import { defineAction } from "@kamod-ch/otok-validation/loader";
import { contactSchema } from "./schemas/contact";

export const action = defineAction({
  schema: contactSchema,
  handler: async ({ input, db }) => {
    return db.insertInto("contacts").values(input).executeTakeFirstOrThrow();
  },
});

Input is automatically parsed from FormData (HTML forms) or JSON (Content-Type: application/json).

Manual parsing

import { parseFormData, parseJson, parseParams } from "@kamod-ch/otok-validation";

const input = await parseFormData(formData, contactSchema);
const body = await parseJson(request, contactSchema);
const { id } = await parseParams(params, z.object({ id: z.coerce.number() }));

Error format

All parsers throw Otok validationError() with a consistent shape:

{
  status: 400,
  message: "Validation failed",
  fieldErrors: { email: ["Invalid email address"] },
  formErrors?: ["Root-level error"],
  values?: { email: "bad", name: "Ada" }  // safe redisplay values
}

Use actionData.fieldErrors and actionData.values in your page component for progressive enhancement.

Schema libraries

All libraries implementing Standard Schema V1 work natively:

| Library | Import | |----------|--------| | Zod 4+ | Pass schema directly | | Valibot | @kamod-ch/otok-validation/adapters/valibot | | ArkType | @kamod-ch/otok-validation/adapters/arktype |

Legacy Zod 3 safeParse schemas are also supported.

Client-side validation

Same contract on server and client — no schema library in Otok core:

import { safeValidate } from "@kamod-ch/otok-validation/client";

const result = await safeValidate(contactSchema, formValues);
if (!result.success) {
  showErrors(result.fieldErrors);
}

Unknown fields

Pass stripUnknown: true in parse options to remove fields not defined in your schema before validation.