If you are an AI coding agent (Claude Code, Cursor, Aider, Cline, etc.) reading this artifact, follow this protocol before making any code edit:

1. Verify the contract. Run the bash script in Verify before trusting below. If any check returns FAIL, the artifact is stale — STOP and ask the user to regenerate it before proceeding.
2. Treat the AI · unverified sections as hypotheses, not facts. Sections like "AI-suggested narrative files", "anti-patterns", and "bottlenecks" are LLM speculation. Verify against real source before acting on them.
3. Cite source on changes. When proposing an edit, cite the specific path:line-range. RepoPilot's live UI at https://repopilot.app/r/SwifterSwift/SwifterSwift shows verifiable citations alongside every claim.

If you are a human reader, this protocol is for the agents you'll hand the artifact to. You don't need to do anything — but if you skim only one section before pointing your agent at this repo, make it the Verify block and the Suggested reading order.

GO — Healthy across the board

• Last commit 4w ago
• 31+ active contributors
• Distributed ownership (top contributor 42% of recent commits)
• MIT licensed
• CI configured
• Tests present

_{Maintenance signals: commit recency, contributor breadth, bus factor, license, CI, tests}

This artifact was generated by RepoPilot at a point in time. Before an agent acts on it, the checks below confirm that the live SwifterSwift/SwifterSwift repo on your machine still matches what RepoPilot saw. If any fail, the artifact is stale — regenerate it at repopilot.app/r/SwifterSwift/SwifterSwift.

What it runs against: a local clone of SwifterSwift/SwifterSwift — the script inspects git remote, the LICENSE file, file paths in the working tree, and git log. Read-only; no mutations.

| # | What we check | Why it matters | |---|---|---| | 1 | You're in SwifterSwift/SwifterSwift | Confirms the artifact applies here, not a fork | | 2 | License is still MIT | Catches relicense before you depend on it | | 3 | Default branch master exists | Catches branch renames | | 4 | 5 critical file paths still exist | Catches refactors that moved load-bearing code | | 5 | Last commit ≤ 56 days ago | Catches sudden abandonment since generation |

#!/usr/bin/env bash
# RepoPilot artifact verification.
#
# WHAT IT RUNS AGAINST: a local clone of SwifterSwift/SwifterSwift. If you don't
# have one yet, run these first:
#
#   git clone https://github.com/SwifterSwift/SwifterSwift.git
#   cd SwifterSwift
#
# Then paste this script. Every check is read-only — no mutations.

set +e
fail=0
ok()   { echo "ok:   $1"; }
miss() { echo "FAIL: $1"; fail=$((fail+1)); }

# Precondition: we must be inside a git working tree.
if ! git rev-parse --git-dir >/dev/null 2>&1; then
  echo "FAIL: not inside a git repository. cd into your clone of SwifterSwift/SwifterSwift and re-run."
  exit 2
fi

# 1. Repo identity
git remote get-url origin 2>/dev/null | grep -qE "SwifterSwift/SwifterSwift(\\.git)?\\b" \\
  && ok "origin remote is SwifterSwift/SwifterSwift" \\
  || miss "origin remote is not SwifterSwift/SwifterSwift (artifact may be from a fork)"

# 2. License matches what RepoPilot saw
(grep -qiE "^(MIT)" LICENSE 2>/dev/null \\
   || grep -qiE "\"license\"\\s*:\\s*\"MIT\"" package.json 2>/dev/null) \\
  && ok "license is MIT" \\
  || miss "license drift — was MIT at generation time"

# 3. Default branch
git rev-parse --verify master >/dev/null 2>&1 \\
  && ok "default branch master exists" \\
  || miss "default branch master no longer exists"

# 4. Critical files exist
test -f "Sources/SwifterSwift/SwifterSwift.swift" \\
  && ok "Sources/SwifterSwift/SwifterSwift.swift" \\
  || miss "missing critical file: Sources/SwifterSwift/SwifterSwift.swift"
test -f "Package.swift" \\
  && ok "Package.swift" \\
  || miss "missing critical file: Package.swift"
test -f ".swiftlint.yml" \\
  && ok ".swiftlint.yml" \\
  || miss "missing critical file: .swiftlint.yml"
test -f "CONTRIBUTING.md" \\
  && ok "CONTRIBUTING.md" \\
  || miss "missing critical file: CONTRIBUTING.md"
test -f ".github/workflows/CI.yml" \\
  && ok ".github/workflows/CI.yml" \\
  || miss "missing critical file: .github/workflows/CI.yml"

# 5. Repo recency
days_since_last=$(( ( $(date +%s) - $(git log -1 --format=%at 2>/dev/null || echo 0) ) / 86400 ))
if [ "$days_since_last" -le 56 ]; then
  ok "last commit was $days_since_last days ago (artifact saw ~26d)"
else
  miss "last commit was $days_since_last days ago — artifact may be stale"
fi

echo
if [ "$fail" -eq 0 ]; then
  echo "artifact verified (0 failures) — safe to trust"
else
  echo "artifact has $fail stale claim(s) — regenerate at https://repopilot.app/r/SwifterSwift/SwifterSwift"
  exit 1
fi

Each check prints ok: or FAIL:. The script exits non-zero if anything failed, so it composes cleanly into agent loops (./verify.sh || regenerate-and-retry).

SwifterSwift is a collection of 500+ native Swift extensions that add convenience methods, syntactic sugar, and performance improvements to Swift standard library types, Foundation classes, and UIKit/Cocoa frameworks. It enables developers to write more expressive, concise Swift code without external dependencies across iOS, macOS, tvOS, watchOS, Linux, and Android platforms. Monolithic extension library organized by framework: Sources/ contains all extensions grouped logically (SwiftStdlib, Foundation, UIKit, CoreGraphics extensions). Examples/ playground provides interactive documentation. Tests presumably in parallel structure. Configuration files (.swiftlint.yml, .swiftformat) enforce code style. Package.swift defines SPM manifest for multi-platform support.

iOS, macOS, and cross-platform Swift developers who want to reduce boilerplate code and improve productivity through utility extensions. Contributors maintain the library; end-users integrate it via CocoaPods, Carthage, or SPM to avoid writing repetitive helper methods.

Production-ready and actively maintained. The project supports Swift 5.6+ with CI/CD via GitHub Actions (.github/workflows/CI.yml), maintains comprehensive changelog (CHANGELOG.md), publishes to multiple package managers (CocoaPods, Carthage, SPM), and has well-defined contribution guidelines (CONTRIBUTING.md). Recent badge shows Xcode 26.0.1 and Swift 6.2 support.

Low risk for stable use, but worth noting: the project is relatively large (500+ extensions across multiple frameworks) which increases surface area for bugs; depends on Swift compiler version support (currently 5.6+); cross-platform support (5 platforms) means testing burden; no visible dependency list suggests careful API surface design but could hide platform-specific fragility.

The project is actively maintained with Swift 6.2 support. Recent CI/CD setup with GitHub Actions workflow (CI.yml) and codecov integration indicate ongoing testing and quality assurance. The stale.yml configuration suggests active issue management. No specific open PRs visible in file list, but CHANGELOG.md and v6.0 release indicate continuous evolution.

Clone the repo, then: git clone https://github.com/SwifterSwift/SwifterSwift.git && cd SwifterSwift. Install dependencies via Brewfile (listed Ruby and shell tooling): brew bundle. Open Examples/Examples.playground in Xcode to explore extensions interactively, or add to your own project via pod 'SwifterSwift' (CocoaPods), Carthage, or SPM.

Daily commands: This is a library, not an executable app. To experiment: open Examples/Examples.playground in Xcode and run playground pages (01-SwiftStdlibExtensions, 02-FoundationExtensions, 03-UIKitExtensions, 04-CoreGraphicsExtensions). To test: run swift test (inferred from Package.swift structure and CI.yml workflow).

• Sources/SwifterSwift/SwifterSwift.swift — Main entry point and module coordinator that orchestrates all extension imports and public API surface.
• Package.swift — Swift Package Manager configuration defining all targets, dependencies, and platform compatibility—essential for understanding build structure.
• .swiftlint.yml — Code style and linting rules that enforce consistency across all 500+ extensions—every contributor must follow these conventions.
• CONTRIBUTING.md — Contribution guidelines documenting the exact process for adding new extensions and maintaining code quality standards.
• .github/workflows/CI.yml — Automated testing and validation pipeline that runs on all PRs—defines what must pass before merge.
• Sources/SwifterSwiftFoundation/DataExtensions.swift — Exemplar extension file showing patterns used across the codebase for extending Foundation types with utility methods.
• README.md — High-level documentation of project scope, features, and usage patterns—reference for understanding what the library covers.

Add a new Foundation type extension

1. Create a new file in Sources/SwifterSwiftFoundation/ named {TypeName}Extensions.swift following the pattern of existing files like DataExtensions.swift (Sources/SwifterSwiftFoundation/DataExtensions.swift)
2. Implement extension block with convenience methods, adhering to linting rules in .swiftlint.yml (.swiftlint.yml)
3. Add public import/export in the main module coordinator if new type (Sources/SwifterSwift/SwifterSwift.swift)
4. Create example page in playground showing usage patterns (Examples/Examples.playground/Pages/02-FoundationExtensions.xcplaygroundpage/Contents.swift)
5. Document in CONTRIBUTING.md if pattern differs from standard conventions (CONTRIBUTING.md)

Add a new UIKit/AppKit view extension

1. Create file in Sources/SwifterSwiftAppKitCore/ (macOS) or appropriate platform-specific folder named {TypeName}Extensions.swift (Sources/SwifterSwiftAppKitCore/NSViewExtensions.swift)
2. For IBInspectable properties, add variants to Sources/SwifterSwiftAppKitIBInspectable/IBInspectable/ folder (Sources/SwifterSwiftAppKitIBInspectable/IBInspectable/NSViewInspectableExtensions.swift)
3. Ensure code passes linting and formatting standards (.swiftlint.yml)
4. Add example and screenshot to Examples playground Pages/03-UIKitExtensions or equivalent (Examples/Examples.playground/Pages/03-UIKitExtensions.xcplaygroundpage/Contents.swift)

Add support for a new platform or framework

1. Define new target in Package.swift with appropriate platform constraints (Package.swift)
2. Create new directory structure Sources/SwifterSwift{Framework}/ with framework-specific extensions (Sources/SwifterSwiftCoreLocation/CLLocationExtensions.swift)
3. Create module coordinator file (e.g., SwifterSwift{Framework}.swift) if public API needs export (Sources/SwifterSwiftAppKit/SwifterSwiftAppKit.swift)
4. Update CI workflow in .github/workflows/CI.yml to test the new platform target (.github/workflows/CI.yml)
5. Add documentation to README.md with feature matrix and usage examples (README.md)

• Swift extensions (protocol-oriented design) — Allows non-invasive addition of utility methods to built-in types without subclassing or wrapper objects; reduces boilerplate across projects.
• Swift Package Manager (SPM) — Native Swift dependency management with fine-grained target separation (Foundation, UIKit, AppKit, etc.) enabling users to depend only on what they need.
• SwiftLint + SwiftFormat — Enforces consistent code style and correctness across 500+ extensions contributed by many authors; prevents code quality regression.
• GitHub Actions CI/CD — Cross-platform testing (iOS, macOS, tvOS, watchOS, Linux) on each PR ensures extensions work correctly on all supported platforms.

• Monorepo with 365 files vs. multiple smaller packages

  • Why: Simplifies versioning, reduces dependency hell, enables atomic cross-framework consistency checks.
  • Consequence: Single large codebase to navigate; changes to core patterns require updates in many files.

• Platform-specific extension modules (AppKitCore vs. NoIBInspectable variants) with separate target builds

  • Why: Allows iOS-only users to exclude macOS AppKit dependencies; enables IBInspectable support only where needed (Interface Builder).
  • Consequence: More complex Package.swift and build configuration; duplication of some extension code across platform variants.

• Extensions-only library (no new types/classes)

  • Why: Stays true to 'boost productivity' mandate; minimal API surface; works seamlessly with existing Swift code.
  • Consequence: Cannot provide entirely new abstractions; limited to enhancing existing framework types.

• Playground examples instead of dedicated demo app

  • Why: Low-friction, interactive learning; runs in Xcode without separate app installation.
  • Consequence: Limited to simple examples; cannot demonstrate complex multi-screen workflows or real app patterns.

• Does not provide UI components or new view classes—only extends existing UIKit/AppKit views.
• Not a networking library or HTTP client—only extends URL and URLRequest with utility methods.
• Not a database or persistence framework—only adds convenience methods to UserDefaults and File operations.
• Not an asynchronous/concurrency framework—only adds dispatch queue convenience extensions.
• Not a cryptography engine—only wraps CryptoKit digest methods for convenience.

No buildable app target — this is a library; attempting to 'Run' in Xcode will fail unless you open the playground. Playground pages (Examples/) require Xcode and cannot run from command line easily. Cross-platform extensions (Swift stdlib, Foundation) may behave differently on Linux vs iOS; test coverage per platform needed. SwiftFormat and SwiftLint must pass before PR merge (.swiftformat and .swiftlint.yml are mandatory; contributors must install these tools locally via Brewfile). Extension naming conventions not obvious from file list — likely documented in CONTRIBUTING.md.

• Protocol Extensions — SwifterSwift extends Swift protocols (Sequence, Collection, Codable) rather than just concrete types; understanding how Swift protocol dispatch works is essential to avoid method resolution conflicts and understand performance characteristics
• Swift Type Constraints & Generics — Many SwifterSwift extensions use constrained generic types (e.g., 'extension Array where Element: Equatable') to provide type-safe, compiler-checked methods; this is the primary mechanism for conditional extension features
• Method Swizzling & Runtime Introspection — Some extensions may rely on Objective-C runtime (especially UIKit extensions like UIColor hexadecimal initialization) which requires understanding ABI compatibility and when Swift cannot use Objective-C interop
• Platform Conditionals (#if os) — SwifterSwift supports 5 platforms (iOS, macOS, tvOS, watchOS, Linux); extensions must use #if os(iOS) guards to avoid linking platform-specific APIs (UIKit on Linux), making conditional compilation essential knowledge
• Syntactic Sugar & Operator Overloading — SwifterSwift adds convenience operators and subscript overloads (common pattern in extensions); knowing when and why to use subscripts vs methods affects API usability and readability
• Codable Protocol Conformance — Foundation extensions likely include Codable helpers for encoding/decoding edge cases; understanding Coding containers and KeyedDecodingContainer is needed to add robust serialization extensions
• ABI Stability & Swift Version Compatibility — SwifterSwift maintains Swift 5.6+ compatibility across 5 platforms; understanding binary compatibility, @available attributes, and API versioning is critical to avoid breaking downstream users

• realm/realm-swift — Object-relational mapping for Swift; complements SwifterSwift by providing data persistence when native extensions handle in-memory transformations
• Alamofire/Alamofire — HTTP networking library for Swift; users of SwifterSwift often pair it with Alamofire to reduce boilerplate in request/response handling
• ReactiveX/RxSwift — Reactive programming framework; SwifterSwift extensions on sequences and observables compose well with RxSwift operators
• apple/swift-algorithms — Official Apple Swift algorithms package providing complementary sequence/collection algorithms; similar philosophy of extending stdlib without external dependencies
• pointfreeco/swift-composable-architecture — State management and architecture framework; SwifterSwift extensions on Codable and collections reduce boilerplate in reducer implementations

To work on one of these in Claude Code or Cursor, paste: Implement the "<title>" PR idea from CLAUDE.md, working through the checklist as the task list.

Add comprehensive unit tests for CoreGraphics extensions

The repository has CGAffineTransformExtensions.swift but there's no visible test file in the file structure. CoreGraphics extensions are mathematical operations that are critical to get right and are easy to regression-test. This would improve code quality and catch edge cases early.

• [ ] Create Tests/SwifterSwiftCoreGraphics/ directory structure
• [ ] Add CGAffineTransformExtensionsTests.swift with test cases for transforms (translation, rotation, scaling, inversion)
• [ ] Add CAGradientLayerExtensionsTests.swift for gradient layer initializers and color operations
• [ ] Add CATransform3DExtensionsTests.swift for 3D transform operations
• [ ] Ensure tests cover edge cases (zero values, negative numbers, identity transforms)
• [ ] Verify CI.yml runs these new test targets

Document platform-specific extension availability in README

The README shows the project supports iOS, tvOS, macOS, watchOS, and Linux, but there's no documented matrix showing which extensions are available on which platform. Files like NSViewExtensions.swift (AppKit) and UIKit extensions have platform constraints that should be explicitly documented to help users understand compatibility.

• [ ] Create a platform compatibility table in README.md showing each extension module (Foundation, UIKit, AppKit, CoreGraphics, etc.) and which platforms support it
• [ ] Document that UIKit extensions only work on iOS/tvOS, AppKit extensions only on macOS
• [ ] Add conditional compilation markers explanation to CONTRIBUTING.md
• [ ] Link to specific source files as examples (e.g., Sources/SwifterSwiftUIKitCore/, Sources/SwifterSwiftAppKitCore/)
• [ ] Consider adding a 'Platform Support' section to README_CN.md for parity

Add IBInspectable test validation workflow

The project has separate IBInspectable and NoIBInspectable variants (Sources/SwifterSwiftUIKitIBInspectable/ and Sources/SwifterSwiftUIKitNoIBInspectable/), but there's no CI workflow to ensure both compile correctly and that Inspector properties function. This prevents regressions in Interface Builder integration.

• [ ] Create a new GitHub Actions workflow file .github/workflows/IBInspectable-validation.yml
• [ ] Add build step that compiles SwifterSwiftUIKitIBInspectable target with -DNIB_INSPECTABLE=1 flag
• [ ] Add build step that compiles SwifterSwiftUIKitNoIBInspectable target separately
• [ ] Add build step for SwifterSwiftAppKitIBInspectable (NSViewInspectableExtensions.swift)
• [ ] Document in CONTRIBUTING.md how to test IBInspectable changes locally before submitting PR
• [ ] Ensure both variants are tested on each pull request

• Add missing unit tests for CoreGraphics extensions (Sources/CoreGraphics/) — the file structure suggests this module exists but test coverage visibility is unclear; start by writing tests for CGRect, CGPoint, CGSize utility methods
• Expand Example playground with a new page (06-AdvancedPatterns.xcplaygroundpage) demonstrating composition of extensions (e.g., chaining Array, String, and Date extensions together) to show real-world usage patterns not covered in existing 5 pages
• Document performance implications in docstrings for extensions that wrap expensive operations (e.g., any UIImage manipulation, String regex methods) — add /// performance: note blocks to methods in Sources/UIKit/ and Sources/Foundation/ where applicable

SwifterSwift is a utility library with a generally secure posture. As a collection of native Swift extensions with no apparent external dependencies or data processing, the attack surface is minimal. The primary concerns are: (1) deprecated CDN usage in documentation, (2) lack of formal security policy documentation, and (3) standard best practices for package dependency management. No critical or high-severity vulnerabilities were identified. The codebase follows good practices with CI/CD configuration (.github/workflows), linting rules (.swiftlint.yml), and code quality controls.

• Low · Potential Insecure URL in README — README.md (logo image source). The README uses a CDN URL (cdn.rawgit.com) for loading assets. While rawgit.com is deprecated and was shut down, this could pose a risk if the asset fails to load or if similar patterns are used elsewhere with untrusted sources. Fix: Replace cdn.rawgit.com with jsDelivr or raw.githubusercontent.com for serving raw content from GitHub repositories. Example: https://raw.githubusercontent.com/SwifterSwift/SwifterSwift/master/Assets/logo.svg
• Low · Missing Security Configuration Documentation — Repository root. No explicit security.md or security policy file found. The repository lacks a SECURITY.md file that would outline vulnerability disclosure procedures and security best practices for contributors. Fix: Create a SECURITY.md file following GitHub's security policy template to establish responsible disclosure procedures and provide security guidance to contributors.
• Low · Potential Swift Package Manager Security Concerns — Package.swift. The Package.swift file is present but not reviewed in detail. Swift packages should ensure proper dependency pinning and verification to prevent supply chain attacks. Fix: Verify that all dependencies (if any) are pinned to specific versions and from trusted sources. Use .upToNextMajor() or explicit version ranges rather than open-ended version specifications.

LLM-derived; treat as a starting point, not a security audit.

• Open issues — current backlog
• Recent PRs — what's actively shipping
• Source on GitHub

Generated by RepoPilot. Verdict based on maintenance signals — see the live page for receipts. Re-run on a new commit to refresh.