🎯 PreToolUse Modification Hooks Plugin - First Claude Code Plugin with Intelligent Input Modification

[ruvnet]

🎯 PreToolUse Modification Hooks Plugin v2.5.0-alpha.140

The First Claude Code Plugin with Intelligent Tool Input Modification

We're excited to announce the release of Claude-Flow's PreToolUse Modification Hooks Plugin - the first plugin to leverage Claude Code v2.0.10+'s groundbreaking PreToolUse feature for automatic tool input enhancement.

🌟 What Is This?

This plugin automatically modifies tool inputs before execution, providing:

• 🛡️ Safety - Prevents destructive operations
• 📁 Organization - Enforces project structure
• ⚡ Productivity - Expands shortcuts and formats commits

✨ Key Features

🛡️ Safety Enhancements

• Auto-adds -i flag to rm commands for interactive confirmation
• Detects sensitive keywords (password, token, api-key) and warns before execution
• Prevents accidental destruction of production files

📁 Intelligent File Organization

• Never saves to root - Working files automatically routed to proper directories
• Auto-organization:
  • Test files → /tests/
  • Source files → /src/
  • Working docs → /docs/working/
  • Temp files → /tmp/
• Format hints - Suggests Prettier, ESLint, Black based on file type

⚡ Developer Productivity

• Alias expansion: ll → ls -lah, la → ls -la
• Conventional commits: Auto-formats with [feat], [fix], [docs] prefixes
• JIRA integration: Extracts ticket numbers from branch names
• Co-authorship: Adds Co-Authored-By: claude-flow <[email protected]>

🚀 Installation

Method 1: Direct Plugin Installation (Recommended)

# In Claude Code:
/plugin ruvnet/claude-flow

Method 2: Via NPM

npx claude-flow@alpha init --force

📖 Examples

Bash Safety

# Your command:
rm test.txt

# Auto-modified to:
rm -i test.txt
# Note: [Safety: Added -i flag for interactive confirmation]

File Organization

# Your write:
test.js

# Auto-saved to:
src/test.js
# Note: [Organization: Moved source file to /src/] [Tip: Auto-format with Prettier recommended]

Git Commits

# Your commit:
git commit -m "fix auth bug"

# Enhanced to:
[fix] fix auth bug

🤖 Generated with Claude Flow
Co-Authored-By: claude-flow <[email protected]>
# Note: [Auto-formatted: fix type]

Alias Expansion

# Your command:
ll

# Auto-expanded to:
ls -lah
# Note: [Alias: ll → ls -lah]

🔧 How It Works

The plugin uses Claude Code v2.0.10+'s PreToolUse hook system to intercept and modify tool inputs before execution:

1. Claude generates a command (e.g., rm test.txt)
2. PreToolUse hook intercepts the JSON input
3. Plugin analyzes and modifies (adds -i flag)
4. Modified command executes (rm -i test.txt)
5. User sees enhanced version in output

All modifications happen atomically in memory - no intermediate states, clean git history.

🏗️ Technical Implementation

Stdin/Stdout Protocol

The plugin follows PreToolUse's JSON protocol:

Input:

{
  "tool_input": {
    "command": "rm test.txt"
  }
}

Output:

{
  "tool_input": {
    "command": "rm -i test.txt"
  },
  "modification_notes": "[Safety: Added -i flag for interactive confirmation]"
}

Environment Detection

Uses 100ms timeout-based stdin detection to handle all environments:

• ✅ Local development
• ✅ Remote SSH sessions
• ✅ Docker containers
• ✅ Codespaces/Gitpod
• ✅ Any environment where process.stdin.isTTY may be undefined

📦 Plugin Structure

.claude-plugin/
├── hooks/
│   └── hooks.json          # PreToolUse configuration
├── marketplace.json        # Plugin metadata
└── README.md              # Plugin documentation

🔌 Composability

The plugin is fully composable with other stdin/stdout tools:

{
  "matcher": "Write|Edit",
  "hooks": [
    {"command": "cat | npx claude-flow@alpha hooks modify-file"},
    {"command": "cat | npx agent-booster optimize-content"},
    {"command": "cat | npx prettier-cli format-stdin"}
  ]
}

Pipeline: File path modification → Code optimization → Formatting → Single atomic write

📚 Documentation

• Full Guide: docs/HOOKS-V2-MODIFICATION.md
• Plugin Files: .claude-plugin/
• Implementation: src/cli/simple-commands/hooks.js

🎯 Target Markets

• Enterprise Development Teams - Safety & standardization
• Open Source Maintainers - Automated code quality
• AI-Powered Development Tools - Claude Code ecosystem integration
• DevOps & Platform Engineers - Infrastructure-as-code safety

💰 Tiers

• Free (Open Source): Core hooks, community support
• Pro ($19/mo): Advanced memory injection, swarm coordination, neural training
• Enterprise: Custom hooks, SLA, training

🚀 Next Steps

For Users

1. Install the plugin: /plugin ruvnet/claude-flow
2. Try it out with various commands
3. Report any issues or suggestions below
4. Share your experience with the community

For Contributors

1. Review the implementation in PR #790
2. Suggest additional hook ideas (memory injection, swarm coordination, etc.)
3. Help with documentation and examples
4. Build composable integrations (agent-booster, prettier, etc.)

🐛 Testing & Feedback

We need your help testing!

Please try the plugin and report:

• ✅ What works well
• 🐛 Any bugs or issues
• 💡 Feature suggestions
• 📊 Performance impact
• 🤔 UX improvements

Test these scenarios:

• File writes in different directories
• Destructive bash commands (rm, mv, etc.)
• Git commits with various message formats
• Alias expansion (ll, la)
• Files with different extensions (.js, .ts, .py, .go)

📊 Success Metrics (Month 12 Targets)

• 5,000+ GitHub stars
• 50,000 npm downloads/month
• $25K MRR
• 15 enterprise customers
• 90%+ error prevention rate
• 30+ minutes saved per developer per week

🤝 Related

• PR: #790 - Implementation
• Requires: Claude Code >= v2.0.10
• Works with: agent-booster, prettier, and any stdin/stdout tool
• Future: Memory injection hooks, swarm coordination hooks, neural training automation

📢 Spread the Word

If you find this useful, please:

• ⭐ Star the repo
• 🐦 Share on Twitter
• 💬 Tell your team
• 📝 Write a blog post
• 🎥 Create a demo video

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Built with ❤️ by rUv

🤖 Generated with Claude Flow
Co-Authored-By: claude-flow [email protected]