Google reCAPTCHA v3 Cloudflare Worker

Google reCAPTCHA v3 Cloudflare Worker that handles the server-side verification of your reCAPTCHA.

Installation

This requires you to have a Cloudflare Workers account and have the Workers CLI installed. If you haven't already, follow this https://developers.cloudflare.com/workers/get-started/guide

1. Deploy it

2. Set your reCAPTCHA secret key environment variable

$ wrangler secret put RECAPTCHA_SECRET --env recaptcha-worker

3. Write the client-side request code (see Usage)

Usage

Request

From your client-side, make a POST request to your deployed cloudflare worker endpoint with the header field g-recaptcha set to your reCAPTCHA token.

Like so:

$.ajax({
  type: 'POST',
  url: 'https://recaptcha-worker.YOUR-SUBDOMAIN.workers.dev',
  headers: { 'g-recaptcha': YOUR_RECAPTCHA_TOKEN },
  error: function (res, status, error) {
    if (res.status === 400) {
      // Verification failed
    } else {
      // An error occured
      console.log(res.responseText)
    }
  },
  success: function (res) {
    // Verification successful 
    
    // POST the form data to your backend or something
  }
})

Response

If the verification request succeeds, you'll get a 202 HTTP status code response with the body reCAPTCHA passed.

If the verification request fails, you will get 400 HTTP status code response with the body reCAPTCHA failed.

Otherwise, for any other error, you will get 500 HTTP status code response with the body being the error stack.