Introduction

This guide is for developers who need to automatically solve reCAPTCHA Enterprise V2 on Auth0-protected login pages. You will learn how to correctly pass session-dependent parameters, avoid the ERROR_CAPTCHA_UNSOLVABLE error, and get working tokens through the API.

What you should know: basic understanding of HTTP requests, REST APIs, and asynchronous programming in Python.

Getting started

About reCAPTCHA Enterprise V2

reCAPTCHA Enterprise is Google's advanced version of reCAPTCHA, built for business-critical use cases. Compared to the standard v2, the Enterprise version:

• Requires the enterprise=1 parameter in your solver API request
• May use extra parameters like action, data-s, apiDomain
• Often appears on high-security pages, including Auth0-based login flows

Auth0 session specifics

Auth0 login pages generate unique URLs with a state parameter, for example:

https://login.oneassembly.com/u/login?state=hKFo2SB1MTFkY2IyWnN6cEtwMVZ5WkloWlFCTXJvNlc0VXp1VKFur3VuaXZlcnNhbC1sb2dpbqN0aWTZIEdWTDZIeElIU0RGZHV6SG9NMWpVdk1wMmM3Q1R0bjNSo2NpZNkgSnNOTlAwM3pxTDZVQUJjZHlncXFhczZySlpTdmduNzY

This parameter ties the session to a specific browser and IP address. If you send the solver a base URL like https://app.oneassembly.com, it will not see the captcha form and will return ERROR_CAPTCHA_UNSOLVABLE.

Key takeaway: always pass the full dynamic URL with all session parameters in the pageurl field.

Setting up your environment

Installing dependencies

You will need:

• Python 3.7 or newer
• The twocaptcha library

Install the package via pip:

pip install twocaptcha

Getting your API key

1. Sign up on our website
2. Go to your account settings
3. Copy your API key
4. For security, store the key in an environment variable:

# Linux/macOS
export APIKEY_2captcha.com=your_key_here

# Windows (CMD)
set APIKEY_2captcha.com=your_key_here

Analyzing the page

Step 1. Open the login page

Go to the starting URL: https://app.oneassembly.com. You will be automatically redirected to login.oneassembly.com with a state parameter.

Step 2. Open developer tools

Press F12, switch to the Network tab. Refresh the page and look for a request to anchor (this loads the reCAPTCHA widget).

Step 3. Extract the parameters

In the anchor request, find these parameters:

Note: the data-s parameter is not required for this case.

Implementation

Here is a complete working example in Python using the async twocaptcha client.

import asyncio
import os
import sys

# Add the library path if installed locally
sys.path.append(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))

from twocaptcha import AsyncTwoCaptcha

# Get API key from environment variable or set directly (not recommended for production)
api_key = os.getenv('APIKEY_2captcha.com', 'YOUR_API_KEY')

# Solver configuration
config = {
    'server': '2captcha.com',  # or 'rucaptcha.com' for alternative server
    'apiKey': api_key,
    'softId': 123,  # Your software ID (optional, for stats)
    'defaultTimeout': 120,  # Timeout for regular requests, in seconds
    'recaptchaTimeout': 600,  # Timeout specifically for reCAPTCHA, in seconds
    'pollingInterval': 10,  # Result polling interval, in seconds
}

# Initialize async client
solver = AsyncTwoCaptcha(**config)


async def solve_recaptcha_enterprise():
    """
    Solves reCAPTCHA Enterprise V2 for Auth0 page oneassembly.com
    """
    try:
        result = await solver.recaptcha(
            sitekey='6LeSRLUpAAAAAFjsCw4WqcgzM6imNrz2rSS4l_I1',
            # Critical: pass the full URL with the state parameter
            url='https://login.oneassembly.com/u/login?state=hKFo2SAyc2M1dldxTjhMS19TYV9kb2MxM0hCdjJ6MWdWbXZ5dqFur3VuaXZlcnNhbC1sb2dpbqN0aWTZIHdFREliaWgyRXNzSkFsUjVvcHFyVllnYU5sVHp4bHhUo2NpZNkgSnNOTlAwM3pxTDZVQUJjZHlncXFhczZySlpTdmduNzY',
            enterprise=1,  # Required for Enterprise version
            invisible=0,   # 0 = checkbox, 1 = invisible captcha
            action='',     # Optional, if widget does not require action
            # apiDomain='www.recaptcha.net',  # Can be set, but not required
            # Proxies not required for testing, but recommended for production:
            # proxy={'type': 'HTTPS', 'uri': 'login:pass@ip:port'}
        )
        return result
    except Exception as e:
        print(f'Error during captcha solving: {e}')
        sys.exit(1)


if __name__ == '__main__':
    # Run the async function
    result = asyncio.run(solve_recaptcha_enterprise())
    # Output the result: response code and token (or error code)
    print('Result:', result)

Code walkthrough

Use the received token in the standard way for reCAPTCHA.

recaptcha request parameters

result = await solver.recaptcha(
    sitekey='...',
    url='https://login.oneassembly.com/u/login?state=...',
    enterprise=1,
    invisible=0,
    ...
)

• sitekey: the widget's public key, extracted from the anchor request.
• url: the full dynamic URL with the state parameter. This is the key to success.
• enterprise=1: required flag for the Enterprise version. Without it, the task will be processed as a regular reCAPTCHA v2, which will cause an error.
• invisible=0: indicates a checkbox widget, not an invisible captcha.

Error handling

The try/except block catches network exceptions, timeouts, and parameter validation errors. In production, add retry logic and proper logging.

Common issues

Extra resources

• Sandbox: enable sandbox
  Test API requests without writing code

• Python SDK docs: reCAPTCHA Enterprise V2 in the 2captcha-python repo
  Library method details and usage examples for twocaptcha

• API documentation: reCAPTCHA V2 Enterprise
  Full endpoint specs and method parameters

• Support: open a ticket
  Contact support for technical questions

Pre-launch checklist

• API key obtained and verified
• twocaptcha library installed (pip install twocaptcha)
• sitekey extracted
• url parameter contains the full dynamic URL, not just the base domain
• enterprise=1 flag is set
• invisible parameter matches the widget type
• Residential proxies from the target location are configured for production
• User-Agent in requests matches the browser
• Exceptions are handled and error logging is in place
• Tested in sandbox before production launch

Final thoughts

Solving reCAPTCHA Enterprise V2 on Auth0 pages means paying attention to details: dynamic session parameters, correct API flags, and a consistent environment. Follow this guide, and you will reliably get working tokens and integrate captcha solving into your projects with confidence.