Simplify git subtree management through declarative configuration with safe file extraction and validation capabilities.

• Declarative Configuration - Manage subtrees through a simple subtree.yaml file instead of remembering complex git commands
• Atomic Operations - All subtree changes include configuration updates in single commits for perfect consistency
• Safe File Management - Extract files from subtrees with smart overwrite protection and validation
• Developer Experience - Intuitive CLI with clear error messages, dry-run modes, and helpful guidance

• Objectives
• Installation
• Usage Examples
• API Reference
• Platform Compatibility
• Contributing
• License

• Swift 6.0+ toolchain
• macOS 13+ or Linux (glibc 2.27+)
• Git installed and available on PATH

Add the following to your Package.swift dependencies:

dependencies: [
    .package(url: "https://github.com/21-DOT-DEV/subtree.git", from: "1.0.0")
]

Download pre-built binaries from GitHub Releases:

1. Download the appropriate binary for your platform:

   • subtree_1.0.0_macOS_arm64 (Apple Silicon)
   • subtree_1.0.0_macOS_x86_64 (Intel Mac)
   • subtree_1.0.0_linux_x86_64 (Linux)
   • subtree_1.0.0_linux_arm64 (Linux ARM)

2. Make executable and add to PATH:

   chmod +x subtree_1.0.0_macOS_arm64
   mv subtree_1.0.0_macOS_arm64 /usr/local/bin/subtree

Use the artifact bundle for Swift Package Manager integration:

dependencies: [
    .binaryTarget(
        name: "subtree",
        url: "https://github.com/21-DOT-DEV/subtree/releases/download/1.0.0/subtree.artifactbundle.zip",
        checksum: "..."
    )
]

git clone https://github.com/21-DOT-DEV/subtree.git
cd subtree
swift build -c release
./.build/release/subtree --help

Create your first subtree.yaml configuration:

# Create minimal config in your git repository
subtree init

# 🎯 Interactive setup with step-by-step guidance (TTY only)
subtree init --interactive

Add configured subtrees to your repository:

# Add a single subtree by name
subtree add --name example-lib

# Add with explicit overrides
subtree add --name libfoo \
  --remote https://github.com/example/libfoo.git \
  --prefix Vendor/libfoo \
  --ref main \
  --no-squash

# Add all configured subtrees
subtree add --all

Manage subtree updates with various strategies:

# Report pending updates (no changes, exit 5 if updates available)
subtree update

# Apply updates (one commit per subtree on topic branch)
subtree update --commit

# Single commit with all updates on current branch
subtree update --commit --single-commit --on-current

# Dry run to preview changes
subtree update --dry-run

# Remove a configured subtree
subtree remove --name example-lib

Copy files from subtrees to your repository:

# Ad-hoc file extraction with glob patterns
subtree extract --name example-lib --from "docs/**/*.md" --to Docs/

# Multi-pattern extraction (009) - extract from multiple directories at once
subtree extract --name mylib \
  --from "include/**/*.h" \
  --from "src/**/*.c" \
  --to vendor/

# Multi-destination extraction (012) - fan-out to multiple locations
subtree extract --name mylib \
  --from "**/*.h" \
  --to Lib/include/ \
  --to Vendor/headers/

# Combined: multi-pattern + multi-destination (cartesian product)
subtree extract --name mylib \
  --from "*.h" --from "*.c" \
  --to Lib/ --to Vendor/

# Brace expansion (011) - compact patterns with {alternatives}
subtree extract --name mylib --from "*.{h,c,cpp}" --to Sources/
subtree extract --name mylib --from "{src,test}/*.swift" --to Sources/

# Brace expansion with embedded path separators (different directory depths)
subtree extract --name crypto-lib \
  --from "Sources/{PrettyBytes,SecureBytes,BoringSSL/RNG}.swift" \
  --to Crypto/

# With exclusions (applies to all patterns)
subtree extract --name mylib --from "src/**/*.c" --to Sources/ --exclude "**/test/**"

# Save multi-destination mapping for future use
subtree extract --name mylib --from "**/*.h" --to Lib/ --to Vendor/ --persist

# Execute saved mappings from subtree.yaml
subtree extract --name example-lib
subtree extract --all

Remove previously extracted files with checksum validation:

# Clean specific files (validates checksums before deletion)
subtree extract --clean --name mylib --from "src/**/*.c" --to Sources/

# Clean from multiple destinations (012)
subtree extract --clean --name mylib --from "**/*.h" --to Lib/ --to Vendor/

# Clean all saved mappings for a subtree
subtree extract --clean --name mylib

# Clean all mappings for all subtrees
subtree extract --clean --all

# Force clean modified files (skips checksum validation)
subtree extract --clean --force --name mylib --from "*.c" --to Sources/

Verify subtree integrity and synchronization:

# Offline validation against commit hash
subtree validate

# Validate specific subtree with pattern
subtree validate --name example-lib --from "**/*.md"

# Repair discrepancies
subtree validate --repair

# Include remote divergence check
subtree validate --with-remote

• init - Initialize subtree.yaml configuration

  • --import - Scan for existing git subtrees
  • --interactive - Guided setup (TTY only)
  • --force - Overwrite existing configuration

• add - Add configured subtrees

  • --name <name> - Add specific subtree
  • --all - Add all configured subtrees
  • Override flags: --remote, --prefix, --ref, --no-squash

• update - Update subtrees with various strategies

  • --name <name> - Update specific subtree
  • --all - Update all subtrees
  • --commit - Apply updates (default: report only)
  • --mode <branch|tag|release> - Update strategy
  • --branch <name> - Custom topic branch name
  • --single-commit - Squash all updates into one commit
  • --on-current - Apply updates to current branch
  • --dry-run - Preview changes without applying
  • --force - Override safety checks

• remove - Remove configured subtrees

  • --name <name> - Remove specific subtree

• extract - Copy or clean files from subtrees

  • --name <name> - Extract from specific subtree
  • --from <pattern> - Source glob pattern (repeatable for multi-pattern)
  • --to <path> - Destination path
  • --exclude <pattern> - Exclude pattern (repeatable)
  • --all - Execute all saved mappings
  • --persist - Save mapping to subtree.yaml
  • --force - Overwrite git-tracked files / force delete modified files
  • --clean - Remove extracted files (validates checksums first)
  • Multi-destination: Use --to multiple times for fan-out extraction

• validate - Verify subtree integrity

  • --name <name> - Validate specific subtree
  • --from <pattern> - Validate specific files
  • --repair - Fix discrepancies
  • --with-remote - Include remote comparison

• 0 - Success
• 1 - General error
• 2 - Invalid usage or configuration
• 3 - Git operation failure or not in Git repository
• 4 - Configuration file not found
• 5 - Updates available (report mode only)

subtree.yaml schema:

subtrees:
  - name: example-lib                    # Unique identifier
    remote: https://github.com/example/lib.git
    prefix: Sources/ThirdParty/ExampleLib
    branch: main
    squash: true                         # Default: true
    commit: 0123456789abcdef...          # Latest known commit
    extractions:                         # File extraction mappings
      # Single pattern, single destination (legacy format)
      - from: "docs/**/*.md"
        to: Docs/
      # Multi-pattern (009) - union extraction
      - from:
          - "include/**/*.h"
          - "src/**/*.c"
        to: vendor/
        exclude:
          - "**/test/**"
      # Multi-destination (012) - fan-out to multiple locations
      - from: "**/*.h"
        to:
          - Lib/include/
          - Vendor/headers/
      # Combined: multi-pattern + multi-destination
      - from:
          - "*.h"
          - "*.c"
        to:
          - Lib/
          - Vendor/

Dependencies:

• Swift 6.0+ toolchain
• Git (any recent version)
• ArgumentParser 1.6.1
• Yams 6.1.0
• swift-subprocess 0.1.0+
• SemanticVersion 0.5.1

We welcome contributions! Please see our Contributing Guidelines for details.

1. Fork the repository
2. Create a feature branch: git checkout -b feature/amazing-feature
3. Run tests: swift test
4. Make your changes following our coding standards
5. Add tests for new functionality
6. Submit a pull request

git clone https://github.com/21-DOT-DEV/subtree.git
cd subtree
swift build
swift test

This project is licensed under the MIT License - see the LICENSE file for details.