Selection CAPTCHAs

Selection CAPTCHAs

ClickPointCaptcha

Asks the user to click the center of a target shape.

Returns: ChallengeResult; answer is (x, y).

Verify with Euclidean distance using metadata["tolerance"].

solved = (
    (user_x - target_x) ** 2 + (user_y - target_y) ** 2
    <= tolerance ** 2
)

Example: Examples/CaptchaExamples/ClickPointCaptcha/

OddOneOutCaptcha

Displays a grid where one shape differs.

Returns: ChallengeResult; answer is a zero-based item index.

Metadata provides rows, columns and answer_is_zero_based.

Example: Examples/CaptchaExamples/OddOneOutCaptcha/

ShapeCountCaptcha

Asks how many instances of a target shape are visible.

Returns: ChallengeResult; answer is an integer count.

Metadata includes target and total_shapes.

Example: Examples/CaptchaExamples/ShapeCountCaptcha/

ColorChallengeCaptcha

Stroop-style challenge asking for ink color instead of the written word.

Returns: ChallengeResult; answer is the ink color name.

Metadata includes word and ink_color; keep ink_color server-side.

Example: Examples/CaptchaExamples/ColorChallengeCaptcha/