@subako-ai/react-hook-form

react-hook-form as a formTool spec for @subako-ai/tools: the registered names describe the form, setValue is the write, and getValues with formState.errors is the read back.

Requires react-hook-form 7.50 or newer and Node 22 or newer for the build. The package is ESM only.

pnpm add @subako-ai/react-hook-form @subako-ai/tools

fromReactHookForm

import { useTool } from "@subako-ai/react";
import { fromReactHookForm } from "@subako-ai/react-hook-form";
import { formTool } from "@subako-ai/tools";

const form = useForm({ defaultValues: { email: "", message: "" } });
useTool(client, "fill_contact_form", formTool({ ...fromReactHookForm(form), description: "The contact form." }));

fromReactHookForm(form, { schema? }) answers with fields or schema, apply and read, which is everything formTool takes.

It writes with setValue(name, value, { shouldValidate: true, shouldDirty: true }) and reads with getValues() and formState.errors, so the model sees what the form's own validation made of the fill.

Nested and array errors use dotted paths, such as meta.subject and signers.0.email. Root errors are included too, for example root.server.

apply waits for the form to catch up. formTool reads the form back as soon as apply resolves, and setValue returns before two things have happened: the validation it asked for, and the update that publishes the result to formState. So apply awaits trigger() and then a turn of the task queue — waiting for only the first is enough when a fill clears an error and not when it raises one. Without both, a fill is read back with the errors of the fill before it, and a model reading that sees a field it has just corrected still reported as wrong. trigger() validates the whole form, so read reports the form as it now stands rather than only the fields that call happened to write. Without a schema the fields are the registered names, every one of them a string, so a form of numbers or checkboxes wants a schema: any Standard Schema value — zod, valibot, arktype — and, when the library cannot describe itself as JSON Schema, a parameters next to it in the formTool call.

Nested values are written by path. setValue takes a dotted path, so a call of { meta: { subject: "…" } } writes meta.subject rather than meta, and the siblings under meta survive. An array is a leaf: it is what useFieldArray holds, and writing one means replacing it. So is anything carrying a prototype of its own, a Date or a File among them. fieldsOf only sees the top-level keys, so without a schema a nested form advertises meta to the model as a string field, not an object — a nested form wants a schema too.

The form is typed structurally — the setValue, trigger, getValues and formState a UseFormReturn carries — so this package imports nothing from react-hook-form at runtime; the peer states the range that shape was written against.