A blazingly fast, drop-in companion to SwiftPM

Key features

• Fast: cold resolves 4–7× faster than SwiftPM, and a no-op in 20 ms.
• Drop-in: the same Package.resolved, .build/checkouts and workspace-state.json as SwiftPM.
• Familiar: SwiftPM's commands and flags; anything swx doesn't handle is forwarded to swift package.
• Xcode-aware: prepares SourcePackages so xcodebuild builds offline.
• Apple platforms: build, run and test on iOS, watchOS, tvOS and visionOS simulators and devices.
• Toolchains: installs swift.org releases and snapshots, and honours .swift-version.
• Tools and scripts: runs package executables like uvx, and single-file scripts with dependencies.
• Registries: SE-0292 registries with authentication, SE-0391 signatures and SwiftPM's trust store.

Philosophy

The goal of swx is to make working with Swift packages fast, without ever being distinguishable from SwiftPM in the files it leaves behind. To that end, swx:

• Writes exactly what SwiftPM and Xcode would, and proves it with differential checks in CI.
• Does no work it can avoid: an unchanged lockfile is a no-op, and missing checkouts are restored without solving.
• Keeps the network and every core busy, pipelining tag listing, manifest fetches and checkouts with resolution.
• Never guesses: a manifest it can't prove harmless is evaluated by the compiler, as SwiftPM does.
• Leaves building to the build systems: SwiftPM for the host, xcodebuild for Apple platforms.

swx is written in Swift. It reads manifests with SwiftParser, adapts parts of SwiftPM itself, and keeps one global, content-addressed store whose checkouts are copy-on-write clones, so a dependency is fetched once per machine instead of once per project.

Example

swx package resolve        # same Package.resolved as `swift package resolve`
swx build -c release       # resolves, then SwiftPM builds with resolution disabled
swx test
swift build                # still works: everything is already resolved

swx devices                                # simulators and paired devices
swx run  --platform ios HelloApp           # build, install, launch, stream console
swx test --platform watchos                # package tests on a watchOS simulator

swx xcode resolve --source-packages SourcePackages
xcodebuild -clonedSourcePackagesDirPath SourcePackages \
           -disableAutomaticPackageResolution -onlyUsePackageVersionsFromResolvedFile …

#!/usr/bin/env -S swx run
// swx-dependencies:
// .package(url: "https://github.com/apple/swift-argument-parser", from: "1.3.0")

import ArgumentParser

The user guide covers every command.

Performance

Vapor + Fluent (32 packages), Apple Silicon, Swift 6.4. Both tools start from their own empty caches, and every run produced byte-identical files. Scripts/benchmark.py reproduces the runs.

Contributing

A difference from SwiftPM is a bug: please report it. To work on swx, read the contributing guide.

License

swx is licensed under the Apache License v2.0 with Runtime Library Exception, like SwiftPM.