I'm making a call to an API which returns some complicated JSON data. I only need a couple of the fields. When I define a data structure to hold the decoded data, can I just define the fields I need, or do I need to define all the fields that could be returned?

If I need to define all the fields, is there a utility, that given a JSON file, returns the data structure?

If you want to define your own, you can do the following as well.

struct MovieResponse: Codable {
    let movies: [Movie]

    private enum CodingKeys: String, CodingKey {
        case movies = "Search"
    }
}

struct Movie: Codable {
    let title: String
    let year: String
    let imdbId: String
    let poster: String

    private enum CodingKeys: String, CodingKey {
        case title = "Title"
        case year = "Year"
        case imdbId = "imdbID"
        case poster = "Poster"
    }
}