@formspec/dsl

Chain DSL for defining FormSpec forms with TypeScript inference.

Install

pnpm add @formspec/dsl @formspec/build

Or use the umbrella package:

pnpm add formspec

Quick Start

import { field, formspec, group, is, type InferFormSchema, when } from "@formspec/dsl";
import { buildFormSchemas } from "@formspec/build";

const ProfileForm = formspec(
  group(
    "Profile",
    field.text("displayName", { required: true }),
    field.enum("role", ["admin", "member"] as const, { required: true })
  ),
  when(is("role", "admin"), field.boolean("superUser"))
);

type ProfileData = InferFormSchema<typeof ProfileForm>;

const { jsonSchema, uiSchema } = buildFormSchemas(ProfileForm);

Main Builders

• formspec(...elements)
• field.text(name, config?)
• field.number(name, config?)
• field.boolean(name, config?)
• field.enum(name, options, config?)
• field.dynamicEnum(name, source, config?)
• field.dynamicSchema(name, schemaSource, config?)
• field.array(name, ...elements)
• field.arrayWithConfig(name, config, ...elements)
• field.object(name, ...elements)
• field.objectWithConfig(name, config, ...elements)
• group(label, ...elements)
• when(predicate, ...elements)
• is(fieldName, value)
• validateForm(elements)
• logValidationIssues(result)

Notes

• Use as const for enum option arrays when you want literal inference from variables.
• group() is layout-only; it does not change the data shape.
• when() affects UI behavior, not whether a field exists in the JSON Schema.

License

This package is part of the FormSpec monorepo and is released under the MIT License. See LICENSE for details.