diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a7a8631..81cf496 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ on:
       - main
 
 env:
-  DEVELOPER_DIR: "/Applications/Xcode_16.0.app/Contents/Developer"
+  DEVELOPER_DIR: "/Applications/Xcode_26.0.1.app/Contents/Developer"
 
 permissions:
   contents: read
@@ -16,7 +16,7 @@ permissions:
 jobs:
   lint:
     name: Lint
-    runs-on: macos-14
+    runs-on: macos-26
     steps:
     - uses: actions/checkout@v4
     - name: Run setup
@@ -26,7 +26,7 @@ jobs:
 
   build:
     name: Build
-    runs-on: macos-14
+    runs-on: macos-26
     steps:
     - uses: actions/checkout@v4
     - uses: actions/cache@v4
@@ -42,7 +42,7 @@ jobs:
 
   test:
     name: Test
-    runs-on: macos-14
+    runs-on: macos-26
     steps:
     - uses: actions/checkout@v4
     - uses: actions/cache@v4
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..5cbd6a0
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,145 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+SwiftCommons is a collection of simple, small, and reusable Swift components created to support command line tools in [macvm](https://github.com/macvmio). The project currently provides SCInject, a minimalistic and efficient dependency injection container.
+
+## Build Commands
+
+This project uses `mise` as the task runner. Common commands:
+
+```bash
+# Build the project
+make build
+# or directly:
+mise run build
+
+# Run tests
+make test
+# or:
+mise run test
+
+# Run a single test
+swift test --filter <test-name>
+
+# Format code (uses SwiftFormat)
+make format
+
+# Lint code (uses SwiftLint and SwiftFormat)
+make lint
+
+# Auto-fix lint issues
+make autocorrect
+
+# Clean build artifacts
+make clean
+
+# Show build environment
+make env
+```
+
+## Architecture
+
+### SCInject - Dependency Injection Container
+
+SCInject is the primary module providing a lightweight DI container with the following key components:
+
+**Core Protocols:**
+- `Container`: Combines Registry and Resolver functionality
+- `Registry`: Interface for registering dependencies
+- `Resolver`: Interface for resolving dependencies
+- `Assembly`: Protocol for organizing dependency registrations into modular units
+
+**Main Implementation:**
+- `DefaultContainer`: Thread-safe container supporting hierarchical DI with parent-child relationships
+- Supports two scopes:
+  - `.transient`: Creates a new instance on each resolution
+  - `.container`: Singleton behavior - creates once and reuses
+
+**Registration Patterns:**
+```swift
+// Basic registration
+container.register(MyService.self) { r in MyService() }
+
+// With scope
+container.register(MyService.self, .container) { r in MyService() }
+
+// With name
+container.register(MyService.self, name: "special") { r in MyService() }
+```
+
+**Resolution:**
+```swift
+let service = container.resolve(MyService.self)
+let named = container.resolve(MyService.self, name: "special")
+let optional = container.tryResolve(MyService.self)  // Returns nil if not registered
+```
+
+**Assembly Pattern:**
+Use `Assembler` to organize registrations into modular `Assembly` units:
+```swift
+class MyAssembly: Assembly {
+    func assemble(_ registry: Registry) {
+        registry.register(MyService.self) { r in MyService() }
+    }
+}
+
+let assembler = Assembler(container: DefaultContainer())
+    .assemble([MyAssembly()])
+let resolver = assembler.resolver()
+```
+
+**Validation:**
+The container provides a `validate()` method to verify all dependencies can be resolved, useful for catching configuration issues during testing.
+
+### Project Structure
+
+- `Sources/SCInject/`: Main DI container implementation
+  - `Container.swift`: Container protocol and DefaultContainer implementation
+  - `Registry.swift`, `Resolver.swift`: Core protocols
+  - `Assembly.swift`, `Assembler.swift`: Modular registration pattern
+  - `Scope.swift`: Lifecycle management
+  - `RegistrationName.swift`: Named registration support
+- `Sources/SCInjectObjc/`: Objective-C support module
+- `Tests/SCInjectTests/`: Test suite with XCTest
+
+## Swift Language
+
+- Project uses Swift 6 language mode (strict concurrency)
+- Minimum platform versions:
+  - macOS 10.13
+  - iOS 15
+  - visionOS 1
+  - watchOS 9
+  - tvOS 16
+
+## Code Quality
+
+The project enforces code quality through SwiftLint and SwiftFormat:
+
+**SwiftFormat config (.swiftformat):**
+- Max line width: 120 characters
+- Swift version: 5.10
+- Attributes on previous line for functions, types, and vars
+- Wrap arguments/parameters before first
+
+**SwiftLint config (.swiftlint.yml):**
+- Disabled rules: trailing_comma, opening_brace, force_try
+- Identifier name exceptions: `r`, `id`
+- Type name exceptions: `T`
+
+## Development Setup
+
+```bash
+# Install mise (if not already installed)
+make setup
+
+# First time setup
+mise install
+```
+
+The project uses mise (.mise.toml) to manage tool versions:
+- swiftlint 0.54.0
+- swiftformat 0.53.3