JSON to Swift Converter

Swift's Codable protocol (combining Encodable and Decodable) provides built-in JSON serialization that requires struct or class definitions matching the JSON structure. The AllTools JSON to Swift converter generates Codable struct definitions with proper type mappings: JSON strings become String, integers become Int, floating-point numbers become Double, booleans become Bool, nullable values become Optional types (String?), nested objects become separate named structs, and arrays become [ElementType]. CodingKeys enums are generated when JSON key names use snake_case that needs mapping to Swift's camelCase convention — let firstName maps to the JSON key "first_name" via CodingKeys. Swift's strong type system and value semantics make structs the preferred choice over classes for data models — they are copied by value rather than reference, eliminating shared mutable state issues. The converter produces code that works directly with JSONDecoder().decode(ModelType.self, from: data) for deserialization. All code generation runs in the browser — your API data stays on your device, important for iOS developers working with production APIs containing user data.

Apple's Codable system handles most JSON scenarios automatically, but real-world APIs often require customization. Custom CodingKeys handle APIs that use inconsistent naming — mapping "user_id" to userId, "created_at" to createdAt. Custom init(from decoder: Decoder) implementations handle complex cases: APIs that return dates as strings in various formats (ISO 8601, Unix timestamps, custom formats), polymorphic responses where the same field may contain different types, and nested values that need to be flattened into the model. JSONDecoder provides configuration options: dateDecodingStrategy handles date formats (.iso8601, .secondsSince1970, or custom formatters), keyDecodingStrategy (.convertFromSnakeCase) eliminates the need for CodingKeys enums in many cases, and nonConformingFloatDecodingStrategy handles infinity and NaN values. For SwiftUI apps using Combine or async/await networking, Codable models flow naturally through the data pipeline from URLSession response to published state. The AllTools converter generates the foundation — developers add custom decoding logic, default values, and computed properties based on their specific API behaviors.