What it finds

• Unused declarations: classes, structs, enums, protocols, functions and properties
• Assign-only properties, written but never read
• Unused imports
• Redundant public accessibility
• Unused function parameters
• Redundant protocol conformances

A lot of this code is not dead weight to throw away: it is often a feature that was never wired up, a leftover from a refactor, or an API waiting for its first caller. outskirts shows you where it is, and you decide.

Every kind of result, with an example: analysis.

Results can be reported as xcode, json, csv, github-actions, codeclimate or sarif, among others.

Install

brew install tiny-earth-moon/tap/outskirts

Or build from source:

git clone https://github.com/tiny-earth-moon/outskirts
cd outskirts
swift build -c release --product outskirts

Requirements: macOS 15 and Xcode 26 for Xcode projects and Swift packages, or Linux with Swift 6.1.2 for Swift packages.

Quick start

From the root of your project, a guided setup detects the project type and prints the full command:

outskirts scan --setup

Then scan an Xcode project, or a Swift package:

outskirts scan --project MyApp.xcodeproj --schemes MyApp
outskirts scan

Keep your options in a .outskirts.yml file at the project root. To keep a declaration on purpose, add a // outskirts:ignore comment above it.

Coming from Periphery

• A .periphery.yml is still read; .outskirts.yml takes its place when you are ready.
• Baseline files keep working.
• The periphery command keeps working as an alias of outskirts.
• // periphery:ignore comments are still honoured.
• Installed from tiny-earth-moon/tap/periphery? brew upgrade moves you to outskirts.

The full guide: migrating from Periphery.

In CI

# record today's results
outskirts scan --write-baseline baseline.json

# only new results fail
outskirts scan --baseline baseline.json --strict

# annotations on pull requests
outskirts scan --format github-actions

Recipes for GitHub Actions, GitLab and other CI services: continuous integration.

Documentation

The documentation covers everything outskirts does:

• Getting started and configuration
• What it finds, what it keeps and every option
• Comment commands, excluding files and baselines
• Xcode integration and troubleshooting
• Changelog, roadmap and releases