---
title: "Verification challenges"
description: "What an agent can and cannot get through: the measured status per challenge type, the four measuring tools that make it possible, and why there is no captcha-solving service in this product."
canonical: "https://scalebrowser.net/docs/agents/verification"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://scalebrowser.net/llms.txt
> Use this file to discover all available pages before exploring further.

# Verification challenges

> What an agent can and cannot get through: the measured status per challenge type, the four measuring tools that make it possible, and why there is no captcha-solving service in this product.

Most sign-ups end at a challenge. This page is what has actually been measured, not what would be nice.

## What this product does not do
**No paid third-party solver.** No account with a solving service, no key, no per-challenge fee, and no code path that could send a challenge anywhere.

**No detect-captcha tool.** An agent recognises a challenge on the page it is already reading, and works it with the ordinary tools. A tool whose only job is to say "this is a captcha" would add a name for something the agent can already see.

## What "solved" is allowed to mean
Three conditions, all three required, or a row does not move:

1. **End to end against the real page**, never a reproduction. A reproduction proves the mechanics and never the scoring.
2. **Through the MCP tools only.** A helper script driving the same browser is evidence about the challenge, not about this product.
3. **The next step is reached.** The account exists, the page moved on. "No error" is not success.

One run is an observation. Two independent runs are the minimum.

## The status
| Challenge                                     | Status                                                          |
| --------------------------------------------- | ----------------------------------------------------------------- |
| Press and hold (HUMAN Security)               | Solved, in one tool call.                                        |
| Cloudflare Turnstile, invisible               | Passed with no interaction at all.                               |
| Cloudflare Turnstile, managed                 | Passed, including the variant that forces a click.               |
| reCAPTCHA v3                                  | Passed with the same score ordinary Chrome gets on the same line. |
| reCAPTCHA v2, image grid                      | The puzzle opens for ordinary Chrome too, and it was solved.     |
| reCAPTCHA v2, audio alternative               | Solved, by transcribing the clip.                                |
| hCaptcha, image task                          | Solved, five runs out of five on one deployment.                 |
| GeeTest v3 and v4, slider                     | Solved on the first drag.                                        |
| GeeTest v4, icon order, gobang, icon crush    | Solved, first attempt each.                                      |
| Click captcha, icons in order in a photo      | Solved.                                                          |
| Text in an image, two providers               | Solved.                                                          |
| MTCaptcha                                     | Solved.                                                          |
| A question in words, no image                 | Solved. The question is in the page map; no image work needed.   |
| Lemin, fit the piece                          | Solved. Addressable only through the document container.         |
| Rotation captcha                              | **Not solved.** See below.                                       |
| Arkose / FunCaptcha                           | **Never presented**, across five attempts on four real services. |

<Note>

**One deployment passed and another refused the same answers.** hCaptcha's own demo rejected the identical correct answers from the identical browser in the same minute on the same line, while a third-party deployment accepted them. The difference was the site key, not the browser.

That is the honest shape of this whole area: a challenge is scored per site and per request, and no browser passes all of them all of the time.

</Note>

### The rotation captcha is worth reading about
It looks like a failure of ours and is not. Eleven of twenty-four grid positions were tried, covering the whole plausible range with the figure visibly upright, and every one was rejected. The page performs **no network request** while checking.

It compares locally against a value its own rotation controls never set. The challenge is not passable through its own interface, by anyone.

## The four measuring tools
A text map describes controls. It cannot describe how far an image is turned or how wide a gap is, and that is the one place an agent needs something else. All four are in the `extended` set:

| Tool                | What it answers                                                              |
| ------------------- | ------------------------------------------------------------------------------ |
| `measure_frames`    | How a moving element behaves over time, for a slider or an animation.         |
| `measure_gap`       | The distance between two elements, for a puzzle piece and its slot.           |
| `measure_rotation`  | How far an image is turned.                                                   |
| `transcribe_audio`  | An audio challenge as text, through a command **you** configure.               |

`transcribe_audio` ships no model and calls no service. You name a program in `[mcp] transcribe_command`; it takes one argument and prints the text. A local Whisper build transcribed a reCAPTCHA audio clip in 1.3 seconds.

Two more tools carry the rest: `press_and_hold` for hold gestures, and `click` with `at_x`/`at_y` for a challenge that draws its whole task into one canvas, where the element is a picture rather than a control.

## Two conditions that ruin a run
Both were measured, and both are outside the tools.

**A real mouse pointer over a visible window spoils it.** Moving your own mouse over the window mixes genuine input into the dispatched input, and the challenge refuses. Measure headless, or keep your hands off.

**A widget can swap its nodes faster than a reference lives.** Lemin's does. Address the document container instead of the widget's own elements.

## Press and hold, in one call
The challenge asks for **two** presses and says so: press once, wait for the confirmation, press again. A single long press lands correctly and is ignored anyway, because the check is still asleep; after that the widget rebuilds and every further report is delivered into a different execution context, so what gets scored is an empty hold.

Wake press, pause and the long hold with its returning pressure are therefore **one** timeline inside the daemon. The agent calls `press_and_hold` once.

## Next
- [Human input](/docs/behaviour): why the gesture looks the way it does.
- [Tool reference](/docs/agents/tools): the measuring tools in the catalog.
- [Email inboxes](/docs/inboxes): the step right after most challenges.