CapSkip 1.0.2

CapSkip .NET SDK

Official .NET / C# client for the CapSkip local captcha solver.

CapSkip runs on your machine and exposes a standard captcha-solver HTTP API (the familiar in.php / res.php endpoints). This SDK wraps that API with clean, familiar method names, so you can solve captchas locally — no cloud service and no per-solve API fees beyond your CapSkip license.

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

Quick start (5 minutes)

1. Install CapSkip

Download and run the CapSkip desktop app from capskip.com. 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).

Supported captcha types

Documentation

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 polling timeout
    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);

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()
{
    ["version"] = "v3",
    ["action"] = "submit",
    ["score"] = 0.7,
});

Cloudflare Turnstile

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

With a proxy (reCAPTCHA & Turnstile only)

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

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 only — use when submitting challenge-page tokens
}

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.

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 website
• CapSkip API docs
• Report an issue
• NuGet package

License

MIT — see LICENSE.