Micronaut CAPTCHA Integration

Create a user account or log in with an existing one. Then create a new CAPTCHA or select an existing one. If you’re unsure whether TrustCaptcha is right for you, try our CAPTCHA service risk-free for 14 days at no cost.

On the CAPTCHA overview page, you will find all the important information, such as the site key and licence key, and you can also create your API key. Allow your websites to access your CAPTCHA by simply adding them to the access authorised domain list in the CAPTCHA security rules.

Drop the TrustCaptcha widget into the HTML form your Micronaut controller serves. The widget runs the CAPTCHA in the background and adds a hidden tc-verification-token field on submit, which Micronaut then exposes to your @Post method.

<script type="module" src="https://cdn.trustcomponent.com/trustcaptcha/3.0.x/trustcaptcha.esm.min.js"></script>

<form method="post" action="/contact">
    <input type="email" name="email" required>
    <trustcaptcha-component sitekey="<your_site_key>"></trustcaptcha-component>
    <button type="submit">Send</button>
</form>

The CAPTCHA widget will then be displayed inside your form:

Need detailed information about the CAPTCHA widget integration?
For the full widget reference — including themes, languages, custom design and more — please read our documentation.

In your Micronaut controller, take the verification token from the form, look up the result via our Java library, and decide whether to accept the request.

First, install our TrustCaptcha Java library:

dependencies {
    implementation 'com.trustcomponent:trustcaptcha:3.0.0'
}

Then validate the token inside your Micronaut controller and act on the result:

@Controller("/contact")
public class ContactController {

  @Post
  @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
  public HttpResponse<String> submit(@Body Map<String, String> form) {
    String token = form.getOrDefault("tc-verification-token", "");

    VerificationResult result;
    try {
      result = TrustCaptcha.getVerificationResult("<your_api_key>", token);
    } catch (CaptchaFailureException e) {
      return HttpResponse.badRequest("CAPTCHA verification failed.");
    }

    if (!result.isVerificationPassed() || result.getScore() > 0.5) {
      return HttpResponse.badRequest("CAPTCHA verification failed.");
    }

    // CAPTCHA passed — process the request
    return HttpResponse.ok("Thanks!");
  }
}

Need detailed information about the Micronaut CAPTCHA integration?
For full step-by-step instructions — including a Bean Validation refactor for projects with several protected endpoints — please read our documentation.

Other backend framework instead of Micronaut?
If you use a different framework, pick the matching recipe here. If your framework isn’t listed, your software developers can integrate the verification themselves using our documentation or ask our support team for a pre-built integration.

You are now protected by TrustCaptcha - congratulations!