Conformal

Type-safe form submissions for the modern web.

Conformal helps you work with native FormData. It solves two major pain points:

• ✅ Strongly typed FormData parsing – Turn native FormData into real objects with full TypeScript inference (nested objects and arrays with dot/bracket notation).
• ✅ Canonical submission flow – A single Submission object that preserves raw input, separates field vs. form errors, and standardizes the success/error states.

Works everywhere: In browsers, Node.js, and edge runtimes with React, Vue, Svelte, or vanilla JavaScript.

Table of Contents

• Getting Started
• Live Examples
• API Reference
• License

Getting Started

Install Conformal via npm or the package manager of your choice:

npm install conformal

Here's a quick example showing how Conformal handles form validation with a user registration form:

import { parseFormData } from "conformal";
import * as z from "zod";

// Tip: Use conformal's coerce functions for form input preprocessing
const schema = z.object({
  name: z.string().min(2, "Name must be at least 2 characters"),
  email: z.email("Invalid email address"),
  age: z.coerce.number().min(18, "Must be at least 18 years old"),
  acceptTerms: z.coerce.boolean(),
});

// In your form action or handler
const result = parseFormData(schema, formData);
const submission = result.submission();

if (submission.status === "success") {
  // submission.value is fully typed: { name: string, email: string, age: number, acceptTerms: boolean }
  console.log("User registered:", submission.value);
} else {
  // submission.fieldErrors contains validation errors: { email: ["Invalid email address"] }
  console.log("Validation errors:", submission.fieldErrors);
  // submission.input preserves the raw user input for re-display
  console.log("User input:", submission.input);
}

That's it! Conformal automatically handles FormData parsing, type coercion, and provides a clean submission interface.

Live Examples

• React - Form actions with useActionState: StackBlitz | Source

• SvelteKit - Server-side form actions: StackBlitz | Source

API Reference

Functions

• parseFormData - Parse FormData with schema validation and get Submission object
• decode - Convert FormData to structured objects (no validation)
• serialize - Transform typed values back to form-compatible strings
• getPath - Safely access nested values using dot/bracket notation
• setPath - Immutably set nested values using dot/bracket notation
• coerceX - A set of coercion functions for use with schema libraries

Types

• Submission - Standardized submission result with success/error states
• PathsFromObject - Type utility to extract all possible object paths

Valibot Utilities

⚠️ Experimental: These utilities are still in development and may change.

• Coercion Pipes - Pipes for automatic form input preprocessing

License

Conformal is licensed under the MIT License.