Go

This is a server-side SDK, which you would use to verify captcha solution against Private Captcha API. This SDK does not solve puzzles on the client side (used to protect APIs).

GitHub repository

Installation

go get -u github.com/PrivateCaptcha/private-captcha-go

Usage

Import and instantiation

Add import:

import pc "github.com/PrivateCaptcha/private-captcha-go"

Create the client:

client, err := pc.NewClient(pc.Configuration{APIKey: "pc_abcdef"})
// ... handle err

Configuration object allows to switch to EU endpoint, specify default form field for the solution, HTTP client, and status code for middleware version.

Verify solution directly

Verify() supports automatic backoff and retrying (configured via VerifyInput parameter), enabled by default. You need to check the captcha verification status yourself.

output, err := client.Verify(ctx, pc.VerifyInput{Solution: solution})
// ... handle err

if !output.Success {
	fmt.Printf("Captcha verification failed. Error: %s", result.Error())
}

Wrapper around HTTP request

VerifyRequest() operates on the http.Request level, extracts and verifies form field, configured via Configuration object for the client instance, with standard defaults. You only need to check if the err == nil.

func handler(w http.ResponseWriter, r *http.Request) {
	if err := client.VerifyRequest(r.Context(), r); err != nil {
		return
	}
}

Simple HTTP middleware

VerifyFunc() is a basic HTTP middleware that returns http.StatusForbidden (configured via Configuration object for client instance) if the captcha solution is not verified.

mux.Handle("POST /my/form", client.VerifyFunc(actualHandler))

Configuration

Client configuration allows to set default form field, domain (can be used for self-hosting or EU isolation) and HTTP status for middleware version.

Non-standard backend domains

For EU isolation, you can use built-in constant EUDomain:

client, err := pc.NewClient(pc.Configuration{Domain: pc.EUDomain})
// ... handle err

For self-hosted installation, use API domain name.

Retry configuration

When verifying puzzle solutions, you can also specify some retry and backoff options.

input := pc.Configuration{
	Solution: "solution",
	MaxBackoffSeconds: 10,
	Attempts: 10,
}
output, err := client.Verify(ctx, input)
// ... handle err