InfoPeak Captcha for Go

Server-side verification for InfoPeak Captcha - the privacy-first, EU-hosted captcha. No tracking, no cookies, no image puzzles.

Install

go get github.com/infopeak/captcha-go

Requires Go 1.20+. Zero dependencies (standard library only).

Usage

Add the widget to your form (full guide):

<form action="/signup" method="POST">
  <input type="email" name="email" required>
  <div class="infopeak-captcha" data-sitekey="YOUR_SITEKEY"></div>
  <button type="submit">Sign up</button>
</form>
<script src="https://captcha.infopeak.io/infopeak-captcha.js" defer></script>

Verify the token when the form is submitted:

import captcha "github.com/infopeak/captcha-go"

var client = captcha.New("YOUR_SITEKEY", os.Getenv("INFOPEAK_CAPTCHA_SECRET"))

func signup(w http.ResponseWriter, r *http.Request) {
    if !client.Verify(r.FormValue(captcha.Field)) {
        http.Error(w, "Captcha verification failed", http.StatusBadRequest)
        return
    }
    // ... proceed
}

Need quota information too?

result := client.VerifyDetailed(token)
result.Valid     // true when the token was genuine and unused
result.OverLimit // true when the sitekey is over its monthly quota

Verification fails closed: network errors and non-200 responses return Valid: false.

Retrying a rejected submission

Tokens are single-use. If you reject a submission and leave the visitor on the same page - an AJAX form, a wrong password, a validation error - the token already in the form is spent, and the next attempt fails on the captcha instead of on the real problem. Ask the widget for a fresh one:

window.infopeakCaptcha.reset();

// Or one specific widget, by element or CSS selector.
window.infopeakCaptcha.reset('#signup-captcha');

reset() clears the hidden field and solves again immediately, and returns the number of widgets it reset. Plain form posts do not need this - the page reload builds a new widget anyway.

Testing

Public test credentials that work on any domain and never count against a quota (never use in production):

sitekey: ipk_test_sitekey
secret:  ipk_test_secret

Links

• Get a free sitekey - 10,000 verifications/month at no cost
• Developer documentation

License

MIT