captcha-jwt-image

Excellent addition 👍 Adding noise_level_percent (default 20%) makes your captcha AI-resistant and future-proof.

API

import { generate_captcha, verify_captcha } from 'captcha-jwt-image';

// Generate
const [captcha_jwt, utf8_captcha_png] = await generate_captcha(
  bg_image_png,
  random_key,
  hash_secret,
  {
    noise_level_percent: 20 // default
  }
);

// Verify
const verifyStatus = verify_captcha(
  captcha_jwt,
  captcha_code_input,
  hash_secret
);

Project Structure

captcha-jwt-image/
├── src/
│   ├── generate.js
│   ├── verify.js
│   ├── render.js
│   ├── crypto.js
│   └── random.js
├── index.js
├── package.json
└── README.md

How this works with any AI agent

This library generates a PNG image with configurable noise levels. By increasing noise_level_percent, you can make the image more difficult for OCR and AI agents to solve, while remaining readable for humans. The verification is handled via JWT, ensuring stateful-less security on the backend.