CapSkip 1.6.0

CapSkip .NET SDK — Captcha Solver for C# and .NET

Solve reCAPTCHA v2, reCAPTCHA v3, Cloudflare Turnstile, GeeTest, ALTCHA, Capy Puzzle, CaptchaFox, Friendly Captcha, AWS WAF, DataDome, hCaptcha and image captchas from C#.

Official .NET client for CapSkip, a local captcha solver that runs on your own machine. Licensed once, not billed per solve.

dotnet add package CapSkip

Targets .NET Standard 2.0, so it runs on .NET 6/7/8/9+, .NET Core 2.0+, and .NET Framework 4.6.1+.

---

How it works

CapSkip is a desktop app. It does the solving on your machine and exposes the standard captcha-solver HTTP API — the same in.php / res.php endpoints every 2captcha-compatible client already speaks — on 127.0.0.1:8080.

This SDK is a thin wrapper over that API, with the method names you would expect: NormalAsync(), RecaptchaAsync(), TurnstileAsync(), GeetestAsync(), AltchaAsync(), CapyAsync(), CaptchaFoxAsync(), FriendlyCaptchaAsync(), AmazonWafAsync(), DataDomeAsync(), HCaptchaAsync(). Nothing leaves your network, and there is no credit balance to keep an eye on.

Supported captcha types

Captcha	Method
Image captcha solver (distorted text / OCR)	solver.NormalAsync(file)
reCAPTCHA v2 solver (checkbox)	solver.RecaptchaAsync(sitekey, url)
reCAPTCHA v2 invisible solver	RecaptchaAsync(sitekey, url, new() { ["invisible"] = 1 })
reCAPTCHA Enterprise solver	RecaptchaAsync(sitekey, url, new() { ["enterprise"] = 1 })
reCAPTCHA v3 solver	RecaptchaAsync(sitekey, url, new() { ["version"] = "v3", ["action"] = "submit" })
reCAPTCHA v3 Enterprise	RecaptchaAsync(sitekey, url, new() { ["version"] = "v3", ["enterprise"] = 1 })
Cloudflare Turnstile solver (widget)	solver.TurnstileAsync(sitekey, url)
Cloudflare Turnstile (challenge page)	TurnstileAsync(sitekey, url, new() { ["data"] = ..., ["pagedata"] = ... })
GeeTest v3 solver (slide puzzle)	solver.GeetestAsync(gt, challenge, url)
ALTCHA solver (proof-of-work)	solver.AltchaAsync(url, options)
Capy Puzzle solver (slide puzzle)	solver.CapyAsync(sitekey, url)
CaptchaFox solver (widget)	solver.CaptchaFoxAsync(sitekey, url)
Friendly Captcha solver (proof-of-work)	FriendlyCaptchaAsync(sitekey, url, new() { ["version"] = "v2" })
AWS WAF solver (challenge page or widget)	solver.AmazonWafAsync(sitekey, url, options)
DataDome solver (slider and device check)	solver.DataDomeAsync(captchaUrl, url)
hCaptcha solver (checkbox, invisible and Enterprise)	solver.HCaptchaAsync(sitekey, url)

The options argument is a Dictionary<string, object?> — the table shortens it to new() { ... } to stay readable; full signatures are in the API Reference.

FunCaptcha/Arkose is not supported. hCaptcha and reCAPTCHA both put a data-sitekey on the widget, so tell them apart before choosing a method: class="h-captcha" or a js.hcaptcha.com script means HCaptchaAsync(), class="g-recaptcha" means RecaptchaAsync().

Point the SDK at the live captcha demo pages to sanity-check your setup against real widgets.

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Quick start (5 minutes)

1. Install the CapSkip captcha solver

Download and run the CapSkip desktop app — CapSkipInstaller.msi. Leave it running in the background.

In CapSkip settings, note:

• API port (default: 8080)
• API key (optional — if validation is disabled, any string works)

2. Install the SDK

dotnet add package CapSkip

3. Solve your first captcha

using CapSkip;

var solver = new CapSkipClient(host: "127.0.0.1", port: 8080);

var result = await solver.RecaptchaAsync(
    "YOUR_SITEKEY",
    "https://example.com/page-with-recaptcha");

Console.WriteLine(result.Code); // g-recaptcha-response token

Prerequisite: CapSkip must be running before you call the SDK. If you see a connection error, see Troubleshooting.

Every solve method is asynchronous — await it (or call .GetAwaiter().GetResult() from synchronous code).

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Why solve captchas locally

Cloud captcha APIs charge per solve, which turns a retry loop into an expense and routes every page URL and sitekey you touch through someone else's queue.

CapSkip flips that around:

• Unlimited solving — one license, no per-captcha charge, no balance to top up
• Runs on 127.0.0.1 — the SDK never talks to a third-party server
• No per-key rate limit — throughput is whatever your machine can manage
• Fast — image captchas come back in well under a second; a typical reCAPTCHA v2 lands in 30–45 seconds

Coming from 2captcha or Anti-Captcha

CapSkip answers on the same in.php / res.php endpoints, so it works as a 2captcha API alternative: an existing integration usually needs nothing more than its host pointed at 127.0.0.1:8080. The migration notes cover the details, if you would rather keep your current client library than switch to this one.

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Documentation

Guide	Description
Tutorial	Complete walkthrough of every captcha type
Getting Started	Full setup: CapSkip app, SDK install, first program
API Reference	All classes, methods, parameters, and return values
Examples	Ready-to-run samples for every captcha type
Troubleshooting	Connection errors, timeouts, proxy issues
Contributing	Development setup, tests, pull requests
Changelog	Release history

---

Configuration

using CapSkip;

var solver = new CapSkipClient(
    apiKey: "capskip",        // your CapSkip API key (or any string if validation is off)
    host: "127.0.0.1",        // CapSkip host
    port: 8080,               // CapSkip port from app settings
    defaultTimeout: 120,      // seconds — image captcha polling timeout
    recaptchaTimeout: 300,    // seconds — reCAPTCHA / Turnstile / GeeTest / CaptchaFox /
                              // Friendly Captcha / AWS WAF / DataDome / hCaptcha polling timeout
                              // (ALTCHA and Capy use defaultTimeout — neither is a browser solve)
    pollingInterval: 5);      // max seconds between res.php polls (starts at 0.25s, backs off to this)

Use environment variables in production:

# Linux / macOS
export CAPSKIP_API_KEY="your-key"
export CAPSKIP_HOST="127.0.0.1"
export CAPSKIP_PORT="8080"

# Windows PowerShell
$env:CAPSKIP_API_KEY = "your-key"
$env:CAPSKIP_HOST = "127.0.0.1"
$env:CAPSKIP_PORT = "8080"

using CapSkip;

var solver = new CapSkipClient(
    apiKey: Environment.GetEnvironmentVariable("CAPSKIP_API_KEY") ?? "capskip",
    host: Environment.GetEnvironmentVariable("CAPSKIP_HOST") ?? "127.0.0.1",
    port: int.TryParse(Environment.GetEnvironmentVariable("CAPSKIP_PORT"), out var p) ? p : 8080);

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Usage examples

Image captcha

await solver.NormalAsync("captcha.png");
await solver.NormalAsync("https://example.com/captcha.jpg");
await solver.NormalAsync("data:image/png;base64,iVBORw0KGgo...");
// result.Code holds the recognized text

reCAPTCHA v2 / v3

// reCAPTCHA v2
var v2 = await solver.RecaptchaAsync("...", "https://example.com");

// reCAPTCHA v3
var v3 = await solver.RecaptchaAsync("...", "https://example.com", new Dictionary<string, object?>
{
    ["version"] = "v3",
    ["action"] = "submit",
    ["score"] = 0.7,
});

Cloudflare Turnstile

var result = await solver.TurnstileAsync("0x4AAAAAAA...", "https://example.com");

GeeTest v3

gt is static per site, but challenge is single-use and expires in about a minute — fetch a fresh pair right before solving.

var result = await solver.GeetestAsync(
    "81388ea1fc187e0c335c0a8907ff2625",
    "7cf6a8b1a2c34d5e6f7089abcdef0123",
    "https://example.com/login");

// Post these back exactly as the site's own front-end would
result.Challenge; result.Validate; result.Seccode;

ALTCHA

ALTCHA is proof-of-work, not recognition — there is nothing to read, so a solve is deterministic and takes milliseconds. Give CapSkip the endpoint that serves the challenge, or the challenge document itself.

var result = await solver.AltchaAsync(
    "https://example.com/signup",
    new Dictionary<string, object?>
    {
        ["challenge_url"] = "https://example.com/captcha/api/altcha/challenge",
    });

// Post this back in the form field the widget uses, named `altcha`
result.Token;

Challenges expire fast — some sites inside two minutes — so fetch one immediately before solving and submit the token promptly.

Capy Puzzle

A Capy solution is not a token. It is three values that together go into the target form, so post all three back exactly as returned.

var result = await solver.CapyAsync(
    "PUZZLE_Abc1dEFghIJKLM2no34P56q7rStu8v",
    "https://example.com/login");

// capy_captchakey, capy_challengekey and capy_answer respectively
result.CaptchaKey; result.ChallengeKey; result.Answer;

Answer is the drag path the widget would have recorded — submit it verbatim, without trimming or re-encoding it. The challenge key is single-use and short-lived, so submit promptly rather than caching the three values.

Pass api_server when the widget script points somewhere other than https://jp.api.capy.me. Only the puzzle family is solved; ["version"] = "avatar" is refused rather than answered with a puzzle answer the site would reject.

CaptchaFox

var result = await solver.CaptchaFoxAsync(
    "sk_xtNxpk6fCdFbxh1_xJeGflSdCE9tn99G",
    "https://example.com/signup");

// Post this back in the form field the widget uses, named `cf-captcha-response`
result.Token;

// The UA the token was minted under — submit under this one, not your own
result.UserAgent;

url has to be the page the widget actually runs on: CaptchaFox checks it against the domains the key is registered for and refuses a mismatch permanently, not intermittently.

Pass api_server only when the page does not load the default widget. A page loading the MAM package expects a MAM_ prefixed token, and sending the wrong source still succeeds — it just returns a token the site will not accept, which reads as a silent verification failure rather than an error.

Friendly Captcha

Two different protocols ship under this name and a sitekey does not tell you which one a site uses, so say which — or send the widget script and let CapSkip read it off the build the site actually loads.

var result = await solver.FriendlyCaptchaAsync(
    "FCMGEMUD2M567T8G",
    "https://example.com/signup",
    new Dictionary<string, object?> { ["version"] = "v2" });

// v1 → frc-captcha-solution, v2 → frc-captcha-response
result.Token;

// Or let the script URL decide the version
var result = await solver.FriendlyCaptchaAsync(
    "FCMGEMUD2M567T8G",
    "https://example.com/signup",
    new Dictionary<string, object?>
    {
        ["module_script"] = "https://cdn.example.com/@friendlycaptcha/sdk@0.1.6/site.min.js",
    });

Solving the wrong version returns a well-formed token the target site rejects, with nothing to indicate the version was the problem. With neither version nor a script URL, v1 is assumed. Pass ["api_server"] = "eu" for a sitekey on the EU data-residency tenant. A v2 token is roughly six kilobytes, so size whatever carries it accordingly.

AWS WAF

An AWS WAF solution is not a token either. It is a voucher and the token it was issued for, which only work as a pair: you trade them with AWS for the aws-waf-token cookie.

On a challenge page (the HTTP 405 page carrying window.gokuProps), the sitekey is gokuProps.key. iv and context are gokuProps.iv and gokuProps.context; they are optional and travel together — send both or neither. Left out, CapSkip reads them from the page at solve time, which is the safer choice when your copy of the page is more than a few minutes old.

var result = await solver.AmazonWafAsync(
    "AQIDAHjcYuEXAMPLEghicBgQ/7bFaQZ+m5FKCMDnO+vTbNg96AHDh0IR5vgzHNceHYqZR+GOAAAAfjB8",
    "https://example.com/",
    new Dictionary<string, object?>
    {
        ["iv"] = "CgAFRDIjfgAAA5yY",
        ["context"] = "Rbp3r8fvbuhmrCqpUe8Mh1TLvs8OSKJZiSs2vCF4dt9rxVZI7xYJa2n5k/9r+XaXe7KUIu2I8nXTDHHkDvIOTDc2",
        ["challenge_script"] = "https://3f2a9c7d41b0.edge.sdk.awswaf.com/3f2a9c7d41b0/8e51d0c7a2f4/challenge.js",
    });

result.CaptchaVoucher; result.ExistingToken;

On a widget page (AwsWafCaptcha.renderCaptcha), the sitekey is the widget's apiKey; pass jsapiScript with the full URL of jsapi.js and no iv / context.

var result = await solver.AmazonWafAsync(
    "Xr9kEXAMPLE2bWQx1vTq8LmZ0aYc4dHs7nFp3gJt6uKw5eRi9AbCdEfGh=_0_1",
    "https://example.com/login",
    new Dictionary<string, object?>
    {
        ["jsapiScript"] = "https://5b7e0a19c3d8.us-east-1.captcha-sdk.awswaf.com/5b7e0a19c3d8/jsapi.js",
    });

To use the result, POST {"captcha_voucher": ..., "existing_token": ...} as JSON to the voucher endpoint beside the page's challenge.js. The token in its response is the aws-waf-token cookie. Exchange the pair as soon as it arrives rather than storing it for later.

Every script URL — challenge_script, captcha_script, jsapiScript — must be an https URL on an awswaf.com host ending in challenge.js, captcha.js or jsapi.js. Anything else is refused with a ValidationException before the request is sent: CapSkip posts the solution to the host the script names, so a script that is not an AWS WAF integration is never accepted. challengeScript, captchaScript and jsapi_script are accepted as aliases. Full parameters are in the CapSkip API docs.

DataDome

DataDome answers a request it doubts with a block page (status 403, sometimes 401) instead of the site. CapSkip passes the challenge on that page, a slider or a device check, and returns the datadome cookie that lets your requests through. The arguments follow 2Captcha's datadome(captcha_url, pageurl, userAgent, proxy): the challenge address and the page URL positionally, and the optional userAgent and proxy in the options dictionary.

var result = await solver.DataDomeAsync(
    "https://geo.captcha-delivery.com/captcha/?initialCid=...&hash=...&cid=...&t=fe&referer=...&s=45225&e=...&dm=cd",
    "https://www.example.com/",                    // the page that returned the block page
    new Dictionary<string, object?>
    {
        ["userAgent"] = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 "
                      + "(KHTML, like Gecko) Chrome/156.0.0.0 Safari/537.36",
        ["proxy"] = new Proxy("HTTP", "login:password@203.0.113.10:8080"),
    });

result.Cookie;     // "datadome=..." -- send it as the Cookie header
result.Code;       // the cookie exactly as DataDome set it: Max-Age, Domain, Path...
result.UserAgent;  // the User-Agent the cookie was earned with
result.Proxy;      // set only when CapSkip picked the proxy, see below

captchaUrl is the address of the challenge iframe on geo.captcha-delivery.com: /captcha/ for a slider, /interstitial/ for a device check. Take the iframe's src when the block page has one; most build it with a script instead, so assemble it from the page's var dd={...} object as the API docs show. Each block page is a fresh challenge, so submit it soon and fetch the page again for the next task. captchaUrl / captchaURL are accepted as option aliases of captcha_url.

The cookie belongs to one IP address and one browser. DataDome refuses it from any other address, or with any other User-Agent, so:

• Send the User-Agent you will use, or none. It must be Chrome for Windows, with the same major version as the browser CapSkip solves with; anything else (Firefox, Safari, Edge, mobile, macOS) would earn a cookie the site rejects, so it is refused with a ValidationException before the request is sent, and a different Chrome major is refused by CapSkip with ERROR_WRONG_USERAGENT. Send none and CapSkip uses its own browser's: copy result.UserAgent into your requests as it is.
• Solve from the address you will use the cookie from. If your requests go out through a proxy, pass that proxy with the task. If they come from the machine running CapSkip, pass none.
• When CapSkip picks the proxy, it tells you which. The CapSkip app has a DataDome proxy list of its own (Settings, Captcha types, DataDome, Configure Proxies). A task sent without a proxy is solved through that list, and the result then carries Proxy as host:port: send the cookie through that proxy, or it will be refused. A proxy you send always takes priority over the list, and then Proxy stays null.

var handler = new HttpClientHandler { UseCookies = false };
if (result.Proxy != null)
{
    // The list's proxy, named without its login: add your credentials if it has one.
    handler.Proxy = new WebProxy($"http://{result.Proxy}");
}

using var http = new HttpClient(handler);
var request = new HttpRequestMessage(HttpMethod.Get, "https://www.example.com/");
request.Headers.TryAddWithoutValidation("User-Agent", result.UserAgent);
request.Headers.TryAddWithoutValidation("Cookie", result.Cookie);
var page = await http.SendAsync(request);

A block page whose dd object carries 't':'bv' means DataDome has banned the address that fetched it; no solve from there can pass, so it is refused before the request is sent. Change the address and request the page again.

hCaptcha

hCaptcha is the checkbox widget behind many sign-up, login and checkout forms. CapSkip passes the widget for the sitekey and page you send and returns the token. The arguments follow 2Captcha's hcaptcha(sitekey, url, ...): the sitekey and the page URL positionally, the rest in the options dictionary. Invisible and Enterprise widgets use the same method.

var result = await solver.HCaptchaAsync(
    "a5f74b19-9e45-40e0-b45d-47ff91b7a6c2",      // data-sitekey of the widget
    "https://accounts.hcaptcha.com/demo",        // the page the widget is on
    new Dictionary<string, object?>
    {
        // ["invisible"] = true,                 // for a widget with data-size="invisible"
        // ["data"] = "...",                     // hCaptcha Enterprise: the rqdata the page passes to hcaptcha.setData()
        // ["userAgent"] = "Mozilla/5.0 ...",    // the User-Agent you will submit the form with
        // ["proxy"] = new Proxy("HTTP", "login:password@203.0.113.10:8080"),
    });

result.Token;      // put it in h-captcha-response (and g-recaptcha-response, if present)
result.RespKey;    // the second value hCaptcha hands the widget; never null, usually empty or unused
result.UserAgent;  // the User-Agent the token was earned with

For an invisible widget there is also a typed overload, HCaptchaAsync(sitekey, url, invisible: true). invisible is sent as 1, or not at all when off; 1/0, true/false and the strings "1", "0", "true", "false" are accepted, and anything else is refused with a ValidationException before the request is sent.

The sitekey is on the widget container as data-sitekey, in the sitekey option of hcaptcha.render(), or in the sitekey= parameter of the hCaptcha iframe's address. An Enterprise rqdata value is issued for one challenge and expires quickly, so read a fresh one for every task.

Put the token in the form's h-captcha-response field (and g-recaptcha-response, if the form has one), or pass it to the widget's data-callback, and submit with the User-Agent from the result. Tokens are single use and expire about two minutes after they are issued, so submit each one soon.

((IJavaScriptExecutor)driver).ExecuteScript(@"
    document.querySelector('[name=""h-captcha-response""]').value = arguments[0];
    const g = document.querySelector('[name=""g-recaptcha-response""]');
    if (g) g.value = arguments[0];", result.Token);

A userAgent you send is used only when it matches the browser CapSkip solves with; the result always names the one the token was actually earned with. At volume, hCaptcha scores the network a token comes from as well as the browser, so send a proxy with each task or configure a pool in the CapSkip app (Settings, Captcha types, hCaptcha, Configure Proxies). If a strict site still refuses the tokens, turn on High score mode for hCaptcha in the same settings page.

With a proxy (every method except image captcha)

// Proxy is not supported for image captcha
await solver.RecaptchaAsync("...", "https://example.com", new Dictionary<string, object?>
{
    ["proxy"] = new Proxy("HTTPS", "user:pass@1.2.3.4:3128"),
});
await solver.TurnstileAsync("...", "https://example.com", new Dictionary<string, object?>
{
    ["proxy"] = new Proxy("HTTP", "1.2.3.4:3128"),
});

Parallel solving

using CapSkip;

var solver = new CapSkipClient();
var results = await Task.WhenAll(
    solver.RecaptchaAsync("...", "https://a.com"),
    solver.TurnstileAsync("...", "https://b.com"));

Console.WriteLine($"{results[0].Code} {results[1].Code}");

AsyncCapSkip is provided as an alias of CapSkipClient — .NET I/O is asynchronous by nature, so every method already returns a Task. It exists for parity with the other CapSkip SDKs.

More examples: examples/

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Selenium, Playwright and PuppeteerSharp

The SDK hands back a token; your existing browser tooling does the driving. The shape is the same whichever you use:

1. Read the sitekey off the page (data-sitekey, or the widget's config object).
2. Call the matching solve method with that sitekey and the page URL.
3. Write the token into the response field and submit.

Selenium WebDriver

var sitekey = driver.FindElement(By.CssSelector("[data-sitekey]")).GetAttribute("data-sitekey");
var result = await solver.RecaptchaAsync(sitekey, driver.Url);

((IJavaScriptExecutor)driver).ExecuteScript(
    "document.getElementById('g-recaptcha-response').value = arguments[0];", result.Code);
driver.FindElement(By.CssSelector("form")).Submit();

Playwright for .NET

var sitekey = await page.GetAttributeAsync("[data-sitekey]", "data-sitekey");
var result = await solver.RecaptchaAsync(sitekey, page.Url);

await page.EvaluateAsync(
    "t => document.getElementById('g-recaptcha-response').value = t", result.Code);

PuppeteerSharp follows the same pattern with page.EvaluateFunctionAsync. Longer walkthroughs: Selenium, Playwright and Puppeteer.

---

Return value

Every solve method resolves to a SolveResult:

public sealed class SolveResult
{
    public string CaptchaId { get; }  // internal ID from CapSkip
    public string Code { get; }       // solution — text for image, token for reCAPTCHA/Turnstile
    public string? UserAgent { get; } // Turnstile, CaptchaFox, DataDome & hCaptcha — the UA that minted the token
    public string? Challenge { get; } // GeeTest only — geetest_challenge
    public string? Validate  { get; } // GeeTest only — geetest_validate
    public string? Seccode   { get; } // GeeTest only — geetest_seccode
    public string? Token     { get; } // ALTCHA, CaptchaFox, Friendly Captcha & hCaptcha — the payload to post back
    public long?   Number    { get; } // ALTCHA only — the counter that solved it
    public string? CaptchaKey   { get; } // Capy only — capy_captchakey
    public string? ChallengeKey { get; } // Capy only — capy_challengekey
    public string? Answer       { get; } // Capy only — capy_answer (the drag path)
    public string? RespKey      { get; } // hCaptcha — never null, "" when none; Capy — empty
    public string? CaptchaVoucher { get; } // AWS WAF only — captcha_voucher
    public string? ExistingToken  { get; } // AWS WAF only — existing_token (pairs with the voucher)
    public string? Cookie    { get; } // DataDome only — the datadome=... pair for a Cookie header
    public string? Proxy     { get; } // DataDome — host:port when CapSkip picked the proxy
}

---

Error handling

All SDK exceptions derive from CapSkipError, so you can catch that one type — or handle each kind:

using CapSkip;

try
{
    var result = await solver.RecaptchaAsync("...", "...");
}
catch (ValidationException)   { /* invalid parameters */ }
catch (NetworkException)      { /* CapSkip not running, or captcha not ready (manual polling) */ }
catch (ApiException)          { /* API returned an error code */ }
catch (CapSkip.TimeoutException) { /* polling timeout exceeded */ }
catch (CapSkipError)          { /* any other CapSkip failure */ }

Note: CapSkip.TimeoutException and CapSkip.ValidationException share their short names with types in System. If you have both using System; and using CapSkip;, qualify them as CapSkip.TimeoutException / CapSkip.ValidationException, or just catch the base CapSkipError.

---

FAQ

How do I solve a captcha in C#?

Install the CapSkip desktop app, dotnet add package CapSkip, then await the method that matches the widget — RecaptchaAsync(), TurnstileAsync(), GeetestAsync(), AltchaAsync(), CapyAsync(), CaptchaFoxAsync(), FriendlyCaptchaAsync(), AmazonWafAsync(), DataDomeAsync(), HCaptchaAsync() or NormalAsync(). Each returns a SolveResult whose Code is the token (a cookie for DataDome), or the recognized text in the case of an image captcha.

Is this a free captcha solver?

The SDK itself is MIT-licensed and free. Solving needs the CapSkip app, which is bought once rather than metered per captcha, so your cost stops scaling with volume.

Which captchas can it solve?

reCAPTCHA v2 (checkbox and invisible), reCAPTCHA v3, reCAPTCHA Enterprise, Cloudflare Turnstile, GeeTest v3, ALTCHA, Capy Puzzle, CaptchaFox, Friendly Captcha, AWS WAF, DataDome, hCaptcha (including invisible and Enterprise), and image/text captchas. Not FunCaptcha/Arkose.

Does it work with Selenium and Playwright?

Yes — see above. The SDK never touches a browser itself, so it drops into whatever stack you already have, PuppeteerSharp and plain HttpClient included.

Which .NET versions are supported?

The package targets .NET Standard 2.0, which covers .NET 6 through 9+, .NET Core 2.0+, and .NET Framework 4.6.1+.

Why is my reCAPTCHA v3 score low?

Google derives v3 scores from IP reputation, cookies and browsing history. A solver returns a valid token, but it cannot change how Google grades that token — score is forwarded as the target you want, not a guarantee. If a site enforces a high threshold, solve through a cleaner IP using the proxy option.

Can I use it as a 2captcha alternative?

Yes. CapSkip serves the same endpoints, so you can either move to this SDK or repoint an existing 2captcha client at 127.0.0.1:8080.

Does the captcha have to be on a public page?

For widget captchas, yes — CapSkip loads the URL you pass it. Image captchas only need the image, and that can be a local file.

---

Development

git clone https://github.com/capskip/capskip-dotnet.git
cd capskip-dotnet
dotnet test

The test suite mocks the HTTP layer and spins up a local mock server — no CapSkip app or network access required. See CONTRIBUTING.md for the full development workflow.

---

Links

• CapSkip — local captcha solver · download the app
• Captcha demo pages — live reCAPTCHA, Turnstile, GeeTest and image widgets
• C# captcha solver guide
• HTTP API docs
• Other clients: Python · Node.js · PHP · MCP server for AI agents
• NuGet package · report an issue

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License

MIT — see LICENSE.