'You forgot to add the secret (=API key) parameter.', 'secret_invalid' => 'The API key you provided was invalid.', 'solution_missing' => 'You forgot to add the secret (=API key) parameter.', 'secret_missing' => 'You forgot to add the solution parameter.', 'bad_request' => 'Something else is wrong with your request, e.g. your request body is empty.', 'solution_invalid' => 'The solution you provided was invalid (perhaps the user tried to tamper with the puzzle).', 'solution_timeout_or_duplicate' => 'The puzzle that the solution was for has expired or has already been used.', 'unexpected' => 'An unexpected error occurred.' ];