@drzl/generator-next

Generate Next.js server actions from a Drizzle schema: one 'use server' module per table, with the FormData readers that turn what a browser posts into what the schemas accept.

The reason this exists

A schema describes a row and a form posts strings, so between the two sits a conversion per column, and every one of them has a wrong answer that looks right.

The one that decides it, measured on 2026-08-11 against zod 4.4.3, valibot 1.1 and arktype 2: <input type="date"> posts 2026-08-11, <input type="datetime-local"> posts 2026-08-11T14:30, and z.iso.datetime() and v.isoTimestamp() refuse every spelling a form control produces. Only a hand-typed 2026-08-11T14:30:00Z gets through. A form wired straight to a generated schema cannot submit a date at all, and the failure is a validation message on a field the user filled in correctly.

Three smaller ones with the same shape: an empty number box posts \'\' and must become NaN rather than 0, because 0 is reported against whatever bound zero happens to break; an unchecked checkbox is absent from FormData rather than posting false; and a blank optional text box posts \'\', which is a value the column would store rather than the absence the user meant.

Install

npm install -D @drzl/generator-next

// drzl.config.ts
export default {
  schema: './src/db/schema.ts',
  generators: [
    { kind: 'zod', path: 'src/validators/zod' },
    { kind: 'next', path: 'src/app/actions' },
  ],
};

That is the whole config. This generator emits no schemas of its own, so the CLI turns on validation.useShared and derives the import path from the sibling generator's path.

What it emits

Per writable table, a 'use server' module carrying create, update and delete actions shaped for useActionState: (prevState, formData) => Promise<FormState>. update reads only the fields the form actually posted, because an update schema makes every column optional and a field the form left out has to stay absent rather than arriving blank.

A table with no primary key keeps create and loses the two that address a row. A materialized view gets no module at all: a server action is a mutation, and a Next server component reads directly.

Plus form-state.ts, which holds FormState, EMPTY_FORM_STATE, fieldErrorsFor and the readers. It is deliberately not 'use server', because such a file may export only async functions and EMPTY_FORM_STATE is a const.

Every message is keyed by the input's name, so rendering one under its field is an index rather than a mapping you maintain.

Timezones

A value from a date input carries no timezone, so dateField reads it as UTC. Not the server's local zone: that makes the same submission mean two different instants depending on which region the server happens to run in. A value that already carries a zone is passed to the schema unchanged.

Licence

Apache-2.0. Generated output is yours under your own project's licence.