# Introduction

> What ZeroCaptcha does, how a task goes from createTask to a token, the three API formats, your key and your prepaid balance, and where to go next.

Source: https://zerocaptcha.io/docs

ZeroCaptcha solves Cloudflare Turnstile widgets and Cloudflare challenge pages through an HTTP API,
for developers who automate, test or collect data on sites they are allowed to access. Sign up with
an email and a password, create your key, add funds in crypto, and send your first task: the
[quickstart](https://zerocaptcha.io/docs/quickstart) walks through it with one complete program in Python, Node, Go or
curl.

## What you can solve

| Task type | What you send | What you get |
| --- | --- | --- |
| `TurnstileTaskProxyless` | The page's URL and its Turnstile site key | A token for the page's form, valid once for 300 seconds |
| `TurnstileTask` | The same, and your proxy | A token, solved through your proxy |
| `CloudflareChallengeTask` | The page behind a Cloudflare challenge, and your proxy | Its `cf_clearance` cookie and the user agent it is bound to |

See [Solving Cloudflare Turnstile](https://zerocaptcha.io/docs/cloudflare-turnstile) and [Cloudflare WAF and 5-second challenges](https://zerocaptcha.io/docs/challenges) for every field.

## How a task works

1. **Create a task.** Send the page and what the task needs. The price is held from your prepaid
   balance, and you get a task ID back at once.
2. **Get the result.** Ask for the task by ID every 2 seconds until it ends, or name a
   [callback](https://zerocaptcha.io/docs/callbacks) URL and we call it when the task ends. A solved task returns the
   token with the time it was issued and when it expires.
3. **Pay only for success.** A solved task turns the hold into a charge. A failed or timed-out task
   releases the hold, so it costs nothing.

[How a task works](https://zerocaptcha.io/docs/how-tasks-work) covers every state, how long each step takes and what is
charged when.

## Three formats, one API

The API is at `https://api.zerocaptcha.io`. It speaks three formats over the same pipeline, with the same prices
and checks:

- **REST v1:** resource URLs, bearer keys, an `Idempotency-Key` header for safe retries, and
  [problem details](https://zerocaptcha.io/docs/reference/errors) for every error. Use it for new code.
- **The [createTask format](https://zerocaptcha.io/docs/createtask):** `createTask`, `getTaskResult` and `getBalance`,
  the shape existing CAPTCHA-solving clients already speak. Change the base URL and the key, and
  they work unchanged.
- **The [2Captcha format](https://zerocaptcha.io/docs/2captcha):** `in.php` and `res.php`, for clients written for
  2Captcha's API v1.

ZeroCaptcha is not affiliated with 2Captcha, CapSolver or Anti-Captcha; their names appear only to
say which API formats it speaks.

## Your API key

There is one kind of key, and it starts with `zc_live_`. Every task it creates is real, and charged
from your balance only when it is solved: there is no sandbox, test key or free credit. Each key is
shown once, when you create it. See [Authentication](https://zerocaptcha.io/docs/authentication) for sending it and
keeping it safe, and [API keys](https://zerocaptcha.io/docs/keys) for scopes, allowlists, spend caps, rotation and
revocation.

## Your balance

ZeroCaptcha is prepaid, in US dollars. You add funds in crypto, from $10 with no maximum, through
our payment processor's checkout page, and the balance pays for your tasks. Top-ups are final. See
[Billing](https://zerocaptcha.io/docs/funds). What each solved task costs today:

| Task | API task type | Price per task | Per 1,000 solved |
| --- | --- | --- | --- |
| Cloudflare Turnstile, your proxy | `TurnstileTask` | $0.0007 | $0.70 |
| Cloudflare Turnstile, proxyless | `TurnstileTaskProxyless` | $0.0008 | $0.80 |
| Cloudflare WAF and 5-second challenge, your proxy | `CloudflareChallengeTask` | $0.0012 | $1.20 |

## Hand it to your AI assistant

Working with an AI coding assistant? Give it [one file](https://zerocaptcha.io/docs/ai) and it has the whole API: every
call, field and error code, the retry rules, tested clients in four languages and a checklist. Every
page here also has **Copy as Markdown** and **Open in Claude** or **ChatGPT** at the top.

## Reference

- [API reference](https://zerocaptcha.io/docs/reference/api): every operation your code can call, generated from the
  API's contract, with samples. The contract itself is at [/openapi.json](https://zerocaptcha.io/openapi.json).
- [Errors](https://zerocaptcha.io/docs/reference/errors): every error code, whether a retry helps, and what it costs.
- [Limits](https://zerocaptcha.io/docs/reference/limits), the [callback payload](https://zerocaptcha.io/docs/reference/callbacks), the
  [FAQ](https://zerocaptcha.io/docs/reference/faq) and the [changelog](https://zerocaptcha.io/docs/reference/changelog).
- The [glossary](https://zerocaptcha.io/glossary): the terms these pages use, such as sitekey, cData and cf_clearance.