Cursor rules for generating React forms from screenshots, PDFs, HTML, or text descriptions with validated FormEngine JSON schema. Renders through RSuite, Material UI, or Mantine.
.cursorrules veya .cursor/rules/react-formengine-ai-form-builder.mdc # FormEngine — AI Form Builder for React
Generate production-ready React forms from a screenshot, PDF, HTML, or
text description. The output is a validated FormEngine JSON schema plus
a runnable App.tsx — portable data, not throwaway JSX.
Default target: FormEngine Core (MIT, free) via `@react-form-builder/core`
+ `@react-form-builder/components-rsuite` (or Material UI / Mantine).
Source repo: https://github.com/lukinov/ai-form-builder
## What you produce — every time
1. `form.json` — a normalized FormEngine schema, validated against the
real list of component types from the target UI library.
2. `App.tsx` — a runnable React file that imports the schema and renders
it through `<FormViewer>`.
3. A short validation report (Screen root, unique keys, layout-only
`css`, no smuggled HTML markup, valid validation rule keys).
4. Install command + a link to the free Online FormBuilder
(https://formbuilder.formengine.io) so the user can tweak visually.
## Hard rules — never violate
### Schema invariants
- Root is `type: "Screen"` (NOT `"Form"`).
- Every component node has `key` (unique within the tree), `type` (must
exist in the chosen library), and usually `props`.
- **Every prop value is wrapped:** `"label": { "value": "Email" }` —
never `"label": "Email"`.
- Validations live under `schema.validations` on the field component
that owns the data — never on the Screen root.
- Use the correct tooltip/error types:
- RSuite: `RsTooltip` / `RsErrorMessage`
- MUI: `MuiTooltip` / `MuiErrorWrapper`
- Mantine: `MtTooltip` / `MtErrorWrapper`
### Layout vs. styling
- `css` and `wrapperCss` are **layout-only** — flex, grid, box-model,
margin, padding, gap, width/height, alignment. **Never** color, font,
background, border, shadow, radius, opacity, transform.
- Visual styling belongs in the UI library's theme provider in
`App.tsx` (`<CustomProvider>` / `<ThemeProvider>` / `<MantineProvider>`).
- The legacy `style` field is **forbidden** — use `css` / `wrapperCss`.
- The shape is `{ "any": { "object": { "<layout-key>": "<value>" } } }`,
never a plain CSS string.
- No companion `.css` file alongside `App.tsx`. No root `className`. No
`<style>` blocks. No `styled-components`.
### Plain-text strings only
Every string inside any prop is plain text. **No HTML markup of any
kind**, anywhere — no `<h1>`, `<p>`, `<strong>`, `<small>`, `<br>`, no
`style="..."`, no `class="..."`, no `<style>` block. Express section
headings and structure with components (`RsCard` with `header` prop,
`RsHeader`, `RsDivider`) — not embedded HTML.
### Validation rule keys — Zod set only
Valid keys: `required`, `nonEmpty`, `min`, `max`, `length`, `email`,
`url`, `uuid`, `ip`, `datetime`, `regex`, `includes`, `startsWith`,
`endsWith`, `lessThan`, `moreThan`, `integer`, `multipleOf`, `truthy`,
`falsy`. There is **no `minLength` / `maxLength`** — use `min` / `max`
with `args.limit`.
## UI library defaults
- **Default to RSuite.** Reference library; widest component set
including `RsWizard` for multi-step forms.
- **Material UI** when the user mentions MUI, Material, or their project
is on MUI.
- **Mantine** when the user mentions Mantine or needs a component that's
Mantine-only (color picker, rich date pickers, segmented control).
State the choice explicitly in the first sentence of the response.
## Common renames — always emit the right name
| Wrong | Right |
|---|---|
| `Form` | `Screen` |
| `RsForm` | `RsCard` or `RsContainer` |
| `RsSelectPicker` | `RsDropdown` |
| `RsRadio` | `RsRadioGroup` |
| `RsTextarea` | `RsTextArea` (capital A) |
| `RsInputNumber` | `RsNumberFormat` |
| `RsUpload` | `RsUploader` |
| `MtDatePickerSingle` | `MtDatePicker` |
| `MtTextField` | `MtTextInput` |
## Side-by-side fields
Use `RsContainer` with `display: flex` and children with
`wrapperCss.any.object.flex: "1"`. RSuite has no FlexboxGrid/Stack
adapter — flex on `RsContainer` is the mechanism.
## Section headings
Use `RsCard` with the `header` prop, or `RsHeader` — never `<h1>` /
`<h2>` embedded in `RsStaticContent` `content` strings.
## Conditional rendering
Use `renderWhen: { "jsCode": "data.X === Y" }` and pair with
`validateWhen` if validations should also be conditional.
## App.tsx — minimal starter
Import only the library's stylesheet. Theme via the library's provider.
No companion CSS. No root className. Layout-level inline styles
(`maxWidth`, `margin`, `padding`) on the wrapping `<div>` are fine.
```tsx
import "rsuite/dist/rsuite.min.css";
import { FormViewer, BiDi } from "@react-form-builder/core";
import { view } from "@react-form-builder/components-rsuite";
import formJson from "./form.json";
const getForm = () => JSON.stringify(formJson);
export default function App() {
return (
<div style={{ maxWidth: 720, margin: "40px auto", padding: 16 }}>
<FormViewer
view={view}
getForm={getForm}
onFormDataChange={(d) => console.log(d)}
biDi={BiDi.LTR}
/>
</div>
);
}
```
## Free vs. commercial — stay on the MIT side
FormEngine **Core** is MIT and free. The Designer and some Premium
components (Signature, DataGrid, Rich Text, QR Code, Google Maps) are
commercial. Don't emit Premium component types unless the user
explicitly asks. Direct people to the free Online FormBuilder
(https://formbuilder.formengine.io) for visual editing.
## Response shape
Lead paragraph (library + field count) → `form.json` → `App.tsx` →
validation checklist → install command → "tweak visually in the Online
FormBuilder" link → 3 next-step doc links into FormEngine Core docs.
## Reference
- FormEngine Core docs: https://formengine.io/documentation/formengine-core/
- Forms JSON reference: https://formengine.io/documentation/formengine-core/forms-json/
- Validation: https://formengine.io/documentation/formengine-core/validation/
- Conditional rendering: https://formengine.io/documentation/formengine-core/conditional-rendering/
- Online FormBuilder: https://formbuilder.formengine.io
- llms-full.txt (full machine-readable docs): https://formengine.io/documentation/llms-full.txt
- Source repo for this rule: https://github.com/lukinov/ai-form-builder Generate production-ready React forms from a screenshot, PDF, HTML, or text description. The output is a validated FormEngine JSON schema plus a runnable App.tsx — portable data, not throwaway JSX.
Default target: FormEngine Core (MIT, free) via @react-form-builder/core
@react-form-builder/components-rsuite (or Material UI / Mantine).Source repo: https://github.com/lukinov/ai-form-builder
form.json — a normalized FormEngine schema, validated against the
real list of component types from the target UI library.App.tsx — a runnable React file that imports the schema and renders
it through <FormViewer>.css, no smuggled HTML markup, valid validation rule keys).type: "Screen" (NOT "Form").key (unique within the tree), type (must
exist in the chosen library), and usually props."label": { "value": "Email" } —
never "label": "Email".schema.validations on the field component
that owns the data — never on the Screen root.RsTooltip / RsErrorMessageMuiTooltip / MuiErrorWrapperMtTooltip / MtErrorWrappercss and wrapperCss are layout-only — flex, grid, box-model,
margin, padding, gap, width/height, alignment. Never color, font,
background, border, shadow, radius, opacity, transform.App.tsx (<CustomProvider> / <ThemeProvider> / <MantineProvider>).style field is forbidden — use css / wrapperCss.{ "any": { "object": { "<layout-key>": "<value>" } } },
never a plain CSS string..css file alongside App.tsx. No root className. No
<style> blocks. No styled-components.Every string inside any prop is plain text. No HTML markup of any
kind, anywhere — no <h1>, <p>, <strong>, <small>, <br>, no
style="...", no class="...", no <style> block. Express section
headings and structure with components (RsCard with header prop,
RsHeader, RsDivider) — not embedded HTML.
Valid keys: required, nonEmpty, min, max, length, email,
url, uuid, ip, datetime, regex, includes, startsWith,
endsWith, lessThan, moreThan, integer, multipleOf, truthy,
falsy. There is no minLength / maxLength — use min / max
with args.limit.
RsWizard for multi-step forms.State the choice explicitly in the first sentence of the response.
| Wrong | Right |
|---|---|
Form | Screen |
RsForm | RsCard or RsContainer |
RsSelectPicker | RsDropdown |
RsRadio | RsRadioGroup |
RsTextarea | RsTextArea (capital A) |
RsInputNumber | RsNumberFormat |
RsUpload | RsUploader |
MtDatePickerSingle | MtDatePicker |
MtTextField | MtTextInput |
Use RsContainer with display: flex and children with
wrapperCss.any.object.flex: "1". RSuite has no FlexboxGrid/Stack
adapter — flex on RsContainer is the mechanism.
Use RsCard with the header prop, or RsHeader — never <h1> /
<h2> embedded in RsStaticContent content strings.
Use renderWhen: { "jsCode": "data.X === Y" } and pair with
validateWhen if validations should also be conditional.
Import only the library’s stylesheet. Theme via the library’s provider.
No companion CSS. No root className. Layout-level inline styles
(maxWidth, margin, padding) on the wrapping <div> are fine.
import "rsuite/dist/rsuite.min.css";
import { FormViewer, BiDi } from "@react-form-builder/core";
import { view } from "@react-form-builder/components-rsuite";
import formJson from "./form.json";
const getForm = () => JSON.stringify(formJson);
export default function App() {
return (
<div style={{ maxWidth: 720, margin: "40px auto", padding: 16 }}>
<FormViewer
view={view}
getForm={getForm}
onFormDataChange={(d) => console.log(d)}
biDi={BiDi.LTR}
/>
</div>
);
}
FormEngine Core is MIT and free. The Designer and some Premium components (Signature, DataGrid, Rich Text, QR Code, Google Maps) are commercial. Don’t emit Premium component types unless the user explicitly asks. Direct people to the free Online FormBuilder (https://formbuilder.formengine.io) for visual editing.
Lead paragraph (library + field count) → form.json → App.tsx →
validation checklist → install command → “tweak visually in the Online
FormBuilder” link → 3 next-step doc links into FormEngine Core docs.
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