@lucas-pmelo/fast-validators

Fast validators for Brazilian documents (CPF, CNPJ), email, plates (classic + Mercosul) and BR phone numbers, implemented in Zig, compiled to WebAssembly, with a thin TypeScript wrapper and Zod adapters.

Why

Validation logic is small but runs on every API request. Pushing it into a tiny .wasm blob keeps it allocation-free and out of the JS GC path.

Install

bun add @lucas-pmelo/fast-validators

Usage

import {
  isValidCPF,
  isValidCNPJ,
  isValidDocument,
  isValidEmail,
  isValidPlate,
  isValidPhone,
} from "@lucas-pmelo/fast-validators";

isValidCPF("111.444.777-35"); // true
isValidCNPJ("11.222.333/0001-81"); // true
isValidDocument("111.444.777-35"); // true (auto-detects CPF or CNPJ)
isValidEmail("[email protected]"); // true
isValidPlate("ABC-1234"); // true (classic)
isValidPlate("ABC1B23"); // true (Mercosul)
isValidPhone("(11) 93333-4444"); // true
isValidPhone("+55 11 93333-4444"); // true (with country code)

Zod adapter

import { z } from "zod";
import { cpf, cnpj, document, email, plate, phone } from "@lucas-pmelo/fast-validators/zod";

const schema = z.object({
  document: document(),
  email: email(),
  plate: plate(),
  phone: phone(),
});

Building from source

Requires Zig 0.16+.

bun run build:wasm       # compile zig -> wasm32-freestanding
bun run build:wasm:test  # run zig unit tests (native)
bun run tsc              # build TS wrapper

How it works

• zig/src/root.zig — pure Zig implementation. Inputs are written into a fixed 256-byte static buffer; each validator returns 0 or 1.
• src/loader.ts — instantiates the wasm module once at import time, exposes writeDigits (digits only), writePlate (alphanumeric, uppercased) and writeAscii (raw ASCII, used for email).
• src/index.ts — public API.
• src/zod.ts — z.string().refine(...) wrappers.