Class

Package

The configuration of a Swift package.

Declaration

final class Package

Overview

Pass configuration options as parameters to your package’s initializer statement to provide the name of the package, its targets, products, dependencies, and other configuration options.

By convention, the properties of a Package are defined in a single nested initializer statement, and not modified after initialization. The following package manifest shows the initialization of a simple package object for the MyLibrary Swift package:

// swift-tools-version:5.1
import PackageDescription

let package = Package(
    name: "MyLibrary",
    platforms: [
        .macOS(.v10_15),
    ],
    products: [
        .library(name: "MyLibrary", targets: ["MyLibrary"]),
    ],
    dependencies: [
        .package(url: "https://url/of/another/package/named/Utility", from: "1.0.0"),
    ],
    targets: [
        .target(name: "MyLibrary", dependencies: ["Utility"]),
        .testTarget(name: "MyLibraryTests", dependencies: ["MyLibrary"]),
    ]
)

A Package.swift manifest file must begin with the string // swift-tools-version: followed by a version number specifier. The following code listing shows a few examples of valid declarations of the Swift tools version:

// swift-tools-version:3.0.2
// swift-tools-version:3.1
// swift-tools-version:4.0
// swift-tools-version:5.0
// swift-tools-version:5.1

The Swift tools version declares the version of the PackageDescription library, the minimum version of the Swift tools and Swift language compatibility version to process the manifest, and the minimum version of the Swift tools that are needed to use the Swift package. Each version of Swift can introduce updates to the PackageDescription framework, but the previous API version will continue to be available to packages which declare a prior tools version. This behavior lets you take advantage of new releases of Swift, the Swift tools, and the PackageDescription library, without having to update your package’s manifest or losing access to existing packages.