logo
bars

FunCaptcha
and CapMonster Cloud

Captcha solving, website integration, and testing.
Inherited a site with a captcha or another protection layer but no access to the source code? In that case you naturally ask: which solution is installed, is it configured correctly, and how can the workflow be tested?

In this article, we have tried to answer all the key questions. The first step in solving the task is to determine which protection system is being used. To do this, you can refer to the list of popular captchas and anti-bot protection systems, where you will find visual examples and key indicators that help you quickly understand what you are dealing with.

If you discover that your site uses FunCaptcha (Arkose Labs CAPTCHA), the next step is to study its properties and operation in more detail. In this article, you can also review the instructions on how to integrate FunCaptcha (Arkose Labs CAPTCHA) so that you fully understand how it functions on your site. This will help you not only understand the current protection, but also properly plan its maintenance.

What is FunCaptcha
What is FunCaptcha
FunCaptcha is an interactive anti-bot protection system developed by Arkose Labs. It verifies whether a user is a real human through game-like and visual challenges that are easy for humans but difficult to automate. FunCaptcha is used to protect registrations, logins, online payments, marketing campaigns, and to prevent fraud, spam, and large-scale automated actions.
Background
Examples of FunCaptcha
Rotating a 3D object
Rotating a 3D object
The user rotates a 3D model or object to place it in the correct position.
Selecting objects by condition
Selecting objects by condition
You need to select images or elements that match a given rule (for example, “select all apples”).
Interactive tasks (drag-and-drop / path following)
Interactive tasks (drag-and-drop / path following)
The user performs actions with elements, such as dragging them along a specific path.
Audio challenges
Audio challenges
The user listens to an audio prompt and selects the correct answer (used less frequently as an alternative to visual challenges).

How to solve FunCaptcha using CapMonster Cloud

When testing forms protected by FunCaptcha, it is often necessary to verify that the captcha works correctly and is properly integrated.
You can manually test the captcha embedded on your website.
  • Open the page with the form and make sure the captcha is displayed.
  • Try submitting the form without solving the captcha — the server should return an error.
  • After successfully solving the captcha, the form should be submitted without errors.
For automatic captcha recognition, you can use specialized services such as CapMonster Cloud — a tool that accepts captcha parameters, processes them on its own servers, and returns a ready-to-use token. This token can be injected into the form to pass the verification without user interaction.

Working with CapMonster Cloud via API typically involves the following steps:

Creating a taskCreating a task
arrow
Sending an API requestSending an API request
arrow
Receiving the resultReceiving the result
arrow
Placing the token on the pagePlacing the token on the page
arrow
How to integrate FunCaptcha into your website
To confidently understand how the captcha works on your website, its verification logic, and how to reconnect or reconfigure it, we recommend reviewing this section. It describes the protection integration process and helps you quickly understand all the details.
  1. Register with Arkose Labs and obtain access to the Arkose Command Center (you can contact them via chat and submit your details in the form, for example here or here).
  2. After gaining access, obtain two keys (Public / Private) in the Settings → Keys section.

    HowTo Connect image 1

  3. If necessary, contact your Customer Success Manager (CSM) to:

    • obtain custom API domains;
    • receive Verify API request and response schemas.

Arkose recommendations

  • Use a Development Key for testing.
  • Use a separate Production Key for each workflow (login, registration, purchase, etc.).
  • Use different keys for different websites.

General workflow

  • The client collects data and displays a challenge if necessary.
  • The client receives a one-time token.
  • The server verifies the token via the Arkose Verify API.

Step 1. Client-side integration

On the browser side (Arkose Bot Manager):

  • analyzes user behavior;
  • displays an Enforcement Challenge if required;
  • returns a one-time session token.

Client API:

  • For testing, you can use:
    client-api.arkoselabs.com
  • For production, it is recommended to specify a custom domain:
    <company>-api.arkoselabs.com

Key requirements

The result of the client-side process is a token that must be sent to the server.

Step 2. Server-side verification

On the server, the token is verified via the Arkose Verify API.

Verify API endpoint

Required request parameters

Example POST request body

The API response contains session information and the verification result.

Key points

How it works:

Background
Possible errors and debugging
Bug Icon
Invalid request parameters
Make sure you correctly specify the Public Key for the client and the Private Key for the server, and that you pass a valid session_token to the Verify API.
Bug Icon
Empty or invalid session_token
The server will receive an empty result or a verification error. Check that the client correctly sends the token after solving the captcha.
Bug Icon
Solution timeout
If the user does not complete the challenge in time, the Arkose server may return an error or reject the verification. Increase the allowed timeout on the server side.
Protection resilience checks
Security and optimization tips
<b>Store the Private Key only on the server</b> and never include it in client-side JavaScript code.
Log full Arkose Verify API responses, including verification status, error codes, and submitted parameters — this helps diagnose issues faster.
Use <b>HTTPS</b> for all requests (client → server → Verify API) to prevent data tampering.
Place links to the <b>Privacy Policy</b> and <b>Arkose Labs Terms of Service</b> on your website, as required by the license.
Conclusion

If you’ve taken over a website that already has a captcha or another protection system installed, but you don’t have access to the code, don’t worry! It’s quite easy to identify which technology is being used. To verify that everything works correctly, you can use the CapMonster Cloud recognition service in an isolated test environment to make sure that the token processing mechanism and the validation logic are functioning properly.

In the case of FunCaptcha, it’s enough to detect the system, observe its behavior, and confirm that the protection is working correctly. In this article, we showed how to identify FunCaptcha and where to find instructions on how to integrate or reconfigure it, so you can confidently maintain the protection and keep its operation under control.

Conclusion
Helpful links
DocIconFunCaptcha documentation (Arkose Labs CAPTCHA)DocIconRequest form for FunCaptcha integrationDocIconCapMonster Cloud documentation (working with FunCaptcha)