friendly-captcha-go-sdk

A Go client for the Friendly Captcha v1 verification API.

Note: This is for Friendly Captcha v1 only, if you are creating a new implementation you probably want to use the new Friendly Captcha Go SDK.

Installation

go get github.com/friendlycaptcha/friendly-captcha-go-sdk

Usage

import "github.com/friendlycaptcha/friendly-captcha-go-sdk"

frcClient := friendlycaptcha.NewClient(apikey, sitekey)

// In your middleware or request handler
solution := r.FormValue(friendlycaptcha.SolutionFormFieldName)
shouldAccept, err := frcClient.CheckCaptchaSolution(r.Context(), solution)

if err != nil {
    if errors.Is(err, friendlycaptcha.ErrVerificationFailedDueToClientError) {
        log.Printf("!!!!!\n\nFriendlyCaptcha is misconfigured! Check your Friendly Captcha API key and sitekey: %v\n", err)
        // Send yourself an alert - the captcha won't be able to do its job to prevent spam.
    } else if (errors.Is(err, friendlycaptcha.ErrVerificationRequest)) {
        log.Printf("Could not talk to the Friendly Captcha API: %v\n", err)
        // Perhaps the Friendly Captcha API is down?
    }
}

if !shouldAccept { // The captcha was invalid
    // Show the user a message that the anti-robot verification failed and that they should try again
    return
}

// The captcha check was succesful, handle the request :)

Beware that the CheckCaptchaSolution function returns two values:

• Whether you should accept the request (bool)
• An error (or nil)

Even if the error is non-nil, the first boolean value may still be true and you should accept the request!

Advanced, optional strictness setting

As a best practice we accept the captcha solution if we are unable to verify it: if we misconfigure our apikey or Friendly Captcha's API goes down we would rather accept all requests than lock all users out.

If you want to change this behavior you can set client.Strict to true, then the accept value will only be true if we were actually able to verify the captcha solution and it was valid.

Example

Run the example

cd examples/form
FRC_SITEKEY=<my sitekey> FRC_APIKEY=<my api key> go run main.go

Then open your browser and head to http://localhost:8844

Note: you can create a sitekey and API key in the Friendly Captcha dashboard.

Example Screenshot

License

MIT