JSON request doesn't always return same response type (object & array) [duplicate]

Answer 1

You have to write a custom initializer. First decode a dictionary, if it fails decode an array

struct Predictions : Decodable {
    let predictions: [Prediction]
    let copyright: String

    private enum CodingKeys: String, CodingKey { case predictions, copyright }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        copyright = try container.decode(String.self, forKey: .copyright)
        do {
            let prediction = try container.decode(Prediction.self, forKey: .predictions)
            predictions = [prediction]
        } catch DecodingError.typeMismatch {
            predictions = try container.decode([Prediction].self, forKey: .predictions)
        }
    }
}