Install periphery with Homebrew, Nix

Project links

• Homepage
• Package manager page

Commands and aliases

• periphery

Project history

Periphery was developed as an open-source Swift static-analysis tool centered on Xcode and Swift Package Manager projects. Its changelog identifies version 1.3.0 in February 2019 as the first open-source release.

The scanner evolved from syntax-oriented analysis toward index-store-based whole-project analysis, adding configuration persistence, CI reuse of existing builds, Bazel support, and handling for newer Swift and Xcode constructs.

The last documented release before archival was in the 3.8 series in July 2026. The official GitHub repository was archived the following month.

Adoption history

Periphery was adopted in iOS, macOS, and Swift package maintenance as a focused way to detect declarations that compile but are no longer reachable. Its support for Xcode, Swift Package Manager, Bazel, local command-line use, and continuous integration made it practical across several Swift build workflows.

Official Homebrew support was added in 2019. In December 2024 the project moved from its custom Homebrew tap into Homebrew's main formula collection. The upstream repository was archived and made read-only on 12 August 2026.

How it is used

Run `periphery scan --setup` for guided initial configuration, then persist established options in `.periphery.yml` at the project root and use `periphery scan` for repeatable analysis.

Periphery builds projects to generate an index store, or CI can reuse a previous build with `--skip-build` and `--index-store-path`. All relevant targets must be built to reduce false positives; standalone frameworks may require `--retain-public`.

Why package nerds care

Periphery fills a narrow gap between compiler diagnostics and general linting: it builds or consumes an index store, constructs a declaration-reference graph, and searches that graph for unused code across project targets.

Its archived status is operationally important to package users. Existing releases remain useful, but adopters should account for the absence of ongoing upstream maintenance when new Swift, Xcode, or project-file formats appear.

Timeline

• 2019: Version 1.3.0 is identified as the first open-source release.
• 2019: Official Homebrew installation support is added.
• 2021: Guided setup gains support for saving `.periphery.yml`.
• 2024: Periphery moves from its custom tap into Homebrew's main formula collection.
• 2026: Version 3.8.0 is released in July.
• 2026: The upstream repository is archived on 12 August.

Related projects

• SwiftLint enforces Swift style and conventions, while SwiftFormat rewrites Swift source into a consistent format. Both address different code-quality concerns from Periphery's unused-code reachability analysis.

Sources

• https://github.com/peripheryapp/periphery#readme
• https://github.com/peripheryapp/periphery/blob/master/CHANGELOG.md