n8n-nodes-captchaai

An n8n community node for CaptchaAI. Solve reCAPTCHA, Cloudflare Turnstile, GeeTest, image CAPTCHAs and more from inside a workflow.

Installation · Credentials · Usage · Supported CAPTCHA types · Settings · Output · Errors · Development

Installation

In n8n, go to Settings → Community nodes → Install and enter:

n8n-nodes-captchaai

For a self-hosted instance you can also install it manually:

cd ~/.n8n
npm install n8n-nodes-captchaai

Restart n8n afterwards. The package ships with no runtime dependencies: the CaptchaAI SDK is bundled into the published build.

Credentials

1. Sign in at captchaai.com and copy your API key from the dashboard. It is exactly 32 characters.
2. In n8n, create a new CaptchaAI API credential and paste the key.
3. Press Test. On success n8n reports how many concurrent solves your plan allows and how many are in use. A rejected key is reported straight away, so you never discover it halfway through a run.

Usage

Add the CaptchaAI node, pick a CAPTCHA Type, and fill in the fields that appear for it. You can switch CAPTCHA Type to expression mode and pass a registry name from upstream data, for example {{ $json.captchaType }} with values such as recaptcha_v2 or turnstile (not the dropdown label). A typical login flow looks like this:

1. HTTP Request fetches the target page.
2. HTML extracts the site key.
3. CaptchaAI solves the CAPTCHA and returns a token.
4. HTTP Request submits the form with {{ $json.solution }} as the g-recaptcha-response value.

The node is also available to AI agents as a tool.

Thread balance

Thread Balance, at the top of the node, reads how many solve threads your plan has free, for example 12 of 15 threads free · 3 currently in use. It reflects whichever CaptchaAI credential is selected on that node. Nothing is selected here and the node ignores the field when it runs; it is there to size Batch Size against your plan before a run rather than after one fails.

n8n caches the reading rather than refetching it as you click around. After you edit the API key, flip Refresh Thread Balance underneath to take a fresh reading — editing a key inside a credential does not notify the node on its own. You can also open the ⋮ menu on the field and choose Refresh List.

Images

Image fields accept an image URL, a data URI, or a base64 string. File paths and binary attachments are rejected: the node never reads files from the n8n server's disk. To use a file already in your workflow, convert it first with an Extract from File node and pass the base64 result in.

PNG and GIF images must be at most 1000px per side.

Execution mode

Sequential solves one item at a time. Parallel solves items in batches of Batch Size. Solving is slow, often 10 to 60 seconds per CAPTCHA, so parallel is worth using for anything more than a couple of items.

Keep Batch Size at or below the thread limit of your CaptchaAI plan. Above it, the extra items fail with a thread limit error.

A failure inside a batch is isolated: its siblings still finish, and the output stays in input order. With Continue On Fail enabled, failed items appear in the output as error items instead of stopping the run.

Supported CAPTCHA types

| Type | Required fields | Optional fields | | --- | --- | --- | | Image (Normal) | Image | Instructions, Character Set, Min/Max Length, Word Count, Case Sensitivity, Language | | Grid | Image, Instructions, Grid Size | | | BLS | Image 1-9, Instructions | | | reCAPTCHA V2 | Site Key, Page URL | Action, Cookies, User Agent | | reCAPTCHA V2 Invisible | Site Key, Page URL | Action, Cookies, User Agent | | reCAPTCHA V2 Enterprise | Site Key, Page URL | Action, Cookies, User Agent | | reCAPTCHA V3 | Site Key, Page URL, Action | Min Score, Cookies, User Agent | | reCAPTCHA V3 Enterprise | Site Key, Page URL, Action | Min Score, Cookies, User Agent | | Cloudflare Turnstile | Site Key, Page URL | Cookies, User Agent | | Cloudflare Challenge | Page URL, plus a proxy | Cookies, User Agent | | GeeTest | GT, Challenge, Page URL | Cookies, User Agent | | CaptchaFox | Site Key, Page URL, plus a proxy | Cookies, User Agent | | Friendly Captcha | Site Key, Page URL | Version | | Lemin | Captcha ID, Div ID, Page URL | API Server |

Cloudflare Challenge and CaptchaFox cannot be solved without a proxy. Set Proxy and Proxy Type in Settings, otherwise the node fails the item before contacting the API.

The GeeTest challenge value is single use. Fetch a fresh one immediately before solving.

Settings

Optional and collapsed by default. These apply to the whole execution.

| Setting | Default | Notes | | --- | --- | --- | | Max Poll Time | 180 seconds | How long to wait for a result before giving up | | Max Retry Attempts | 5 | Retries for transient API errors. Minimum 1 | | Proxy | none | user:password@host:port | | Proxy Type | HTTP | HTTP, HTTPS, SOCKS4, or SOCKS5 | | Include Raw API Response | off | Adds the untouched API response under raw |

Output

One output item per input item:

{
  "captchaType": "recaptcha_v2",
  "taskId": "77123456",
  "solution": "03AGdBq26...",
  "userAgent": "Mozilla/5.0 ..."
}

solution keeps whatever shape the CAPTCHA type produces: a token string for reCAPTCHA and Turnstile, an object for GeeTest and Lemin, an array of tile indices for Grid and BLS.

userAgent is present only for the types that return one, namely reCAPTCHA Enterprise, Cloudflare Challenge, and CaptchaFox. When it is there, reuse it on the follow-up request or the token is likely to be rejected.

raw is present only when Include Raw API Response is enabled.

With Continue On Fail, a failed item looks like this instead:

{
  "error": "Captcha could not be solved",
  "errorType": "UnsolvableError",
  "captchaType": "normal",
  "taskId": "77123456"
}

Errors

Every failure names the CAPTCHA type and, once the task has been submitted, the CaptchaAI task ID, so a run can be traced in your dashboard.

| Error | What it usually means | | --- | --- | | InvalidKeyError | The API key is wrong. Check the credential | | ValidationError | A parameter was rejected, most often a bad site key and page URL pair | | ProxyError | The proxy was rejected or is unreachable from CaptchaAI | | ThreadLimitError | Your account's threads are all busy. Lower Batch Size | | NoThreadsError | The account has no active plan | | UnsolvableError | CaptchaAI could not solve it. You are not charged | | TimeoutError | No result within Max Poll Time. Raise it for slow types | | NetworkError | The API was unreachable | | InputValidationError | A node field is missing or invalid, caught before any request |

Network errors are not retried. They fail the item immediately, by design, so a dead connection does not silently burn the poll budget. Enable Retry On Fail on the node if you want the whole item retried.

Development

npm install
npm run build      # bundle to dist/ and copy icons
npm test           # vitest
npm run lint
npm run typecheck
npm run scan       # build, then run n8n's community-package verification lint

npm run scan reproduces both legs of @n8n/scan-community-package against the working tree: the node and credential sources, and the packed tarball. Run it before publishing, because the published package is scanned the same way.

Two build-time substitutions in tsup.config.ts keep the bundle inside n8n's verification rules, and both are covered by tests:

• build/timers-shim.js routes the bundled SDK's setTimeout calls through n8n's own sleep helper, since referencing the setTimeout global is not allowed in shipped code.
• build/sdk-image-resolver.js replaces the SDK's image helper with an equivalent that has no node:fs import, which is what makes the "URL or base64 only" rule airtight rather than advisory.

License

MIT