Rust CAPTCHA Integration
Add TrustCaptcha to your Rust backend to stop bot sign-ups, form spam, and API abuse. Validate the verification token in minutes with our step-by-step Rust integration. Puzzle-free UX, EU hosting and GDPR-ready processing included.
Quickstart
How the integration works
1. Create a CAPTCHA
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, secret key and licence key. Allow your websites to access your CAPTCHA by simply adding them to the access authorised domain list in the CAPTCHA security rules.


2. Integrate the CAPTCHA widget into your frontend
Integrate the CAPTCHA widget into your website or app. For precise, detailed instructions, please read the CAPTCHA widget guide in our documentation.
Read the documentation
The CAPTCHA widget will then be displayed on your website or app:

Prebuild frontend integrations
You can use one of our pre-built frontend integrations to integrate the CAPTCHA widget into your website or application. If there is no pre-built integration from us for your preferred frontend technology, your software developers can integrate the CAPTCHA themselves using using our documentation or ask our support-team for a pre-built integration solution.
3. Validate the CAPTCHA result in your backend
The following steps give you an idea of how to retrieve the CAPTCHA verification result from our server in a Rust backend and determine how to proceed based on this result. For precise, detailed instructions, please read the CAPTCHA integration guide for Rust in our documentation.
Read the documentation
First, install our TrustCaptcha Rust dependency:
cargo add trustcaptchaRetrieve the verification result from our server using the verification token and the secret key of your CAPTCHA:
// Retrieving the verification result
let verification_result = match CaptchaManager::get_verification_result(secret_key, "<verification_token_from_your_client>").await {
Ok(result) => result,
Err(e) => {
// Fetch verification result failed - handle error
error!("Failed to fetch verification result: {}", e);
return Ok(HttpResponse::InternalServerError().json(json!({"error": "Captcha verification failed"})));
}
};Based on the verification results and your individual needs, decide how you would like to proceed:
// Act on the verification result
if !verification_result.verification_passed || verification_result.score > 0.5 {
info!("Verification failed or bot score > 0.5 – possible automated request.");
}Need detailed information about the Rust CAPTCHA integration?
For detailed instructions on integrating TrustCaptcha, please refer to our Rust CAPTCHA integration guide. A complete integration example for the Rust CAPTCHA can be found in our CAPTCHA Samples Repository on Github.
Other backend technology instead of Rust?
If you do not want to use Rust on your server or have several different backends, you can select a different integration here. If there is no pre-built integration from us for your preferred backend technology, your software developers can integrate the CAPTCHA verification process themselves using our documentation or ask our support-team for a pre-built integration.
4. Congratulations 🎉
You are now protected by TrustCaptcha - congratulations!

FAQs
What do I need to validate a TrustCaptcha CAPTCHA in a Rust backend?
Do I still need a frontend integration if I use Rust on the backend?
How does the verification token reach my Rust backend?
What do “verification passed” and “bot-score” mean?
How should I choose a decision threshold for the bot-score?
How long is a verification token valid, and what happens if the API is not reachable?
TrustCaptcha blocks spam and bots, not customers. No puzzles, GDPR-ready, EU-hosted.


Protect your Rust application with TrustCaptcha in just a few steps!
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