/install
Install the prompt injection defender hooks into your Claude Code project.
$ npx -y skills add lasso-security/claude-hooks --agent claude-codeHow it fires
How this command gets triggered: by you, by Claude, or both.
- Fires itselfClaude auto-loads it when your prompt matches the work.
- You can call itInvoke it directly when you want it.
- Slash command
/install
Context preview
What this command does when you run it.
Install the prompt injection defender hooks into your Claude Code project.
Command definition
install.mdInstall Prompt Injection Defender
Install the prompt injection defender hooks into your Claude Code project.
Instructions
Guide me through installing the prompt injection defender. Ask me:
1. **Which implementation?** Python (uv) or TypeScript (bun) 2. **Installation scope?** Project-only or user-wide 3. **Which tools to monitor?** All recommended tools or let me select
Installation Steps
After gathering my preferences:
1. **Check prerequisites**
- For Python: Verify `uv` is installed (`which uv`)
- For TypeScript: Verify `bun` is installed (`which bun`)
2. **Copy hook files**
- Copy the appropriate hook implementation to my project or user config
- For project: `.claude/hooks/prompt-injection-defender/`
- For user-wide: `~/.claude/hooks/prompt-injection-defender/`
3. **Copy patterns.yaml**
- Place `patterns.yaml` alongside the hook script
- This file contains all detection patterns
4. **Update settings configuration**
- **IMPORTANT**: Check if `.claude/settings.local.json` exists first
- If `settings.local.json` exists, merge hooks into THAT file (it takes precedence over `settings.json`)
- If only `settings.json` exists, merge hooks there
- Use the template from `python-settings.json` or `typescript-settings.json`
- Adjust paths based on installation scope
- For user-wide: update `~/.claude/settings.json`
**Settings precedence (highest to lowest):** 1. `.claude/settings.local.json` (local project - overrides all below) 2. `.claude/settings.json` (project settings) 3. `~/.claude/settings.json` (user settings)
5. **Restart Claude Code**
- **CRITICAL**: Hooks are captured at session startup
- Tell the user they MUST restart Claude Code for hooks to take effect
- Exit the current session and start a new one
6. **Verify installation**
- After restart, run a quick test to ensure the hook is working
- Read a test file with known injection patterns
- Use `/hooks` command to verify hooks are loaded
Recommended Tool Configuration
Monitor these tools for prompt injection:
- `Read` - File contents
- `WebFetch` - Web page contents
- `Bash` - Command outputs
- `Grep` - Search results
- `Task` - Agent outputs
- `mcp__*` - All MCP tool outputs
After Installation
**IMPORTANT**: Tell the user to restart Claude Code! Hooks only load at startup.
Explain what will happen after restart:
- When Claude reads files, fetches web pages, or runs commands
- The hook will scan the output for injection patterns
- If patterns are detected, Claude will see a warning
- Processing continues but Claude is warned to be cautious
The user can verify hooks are active by running `/hooks` in Claude Code.
Reference Files
- Skill location: `.claude/skills/prompt-injection-defender/`
- Python hook: `hooks/defender-python/post-tool-defender.py`
- TypeScript hook: `hooks/defender-typescript/post-tool-defender.ts`
- Patterns: `patterns.yaml`
- Settings templates: `python-settings.json` / `typescript-settings.json`
Read more
Install Prompt Injection Defender
Install the prompt injection defender hooks into your Claude Code project.
Instructions
Guide me through installing the prompt injection defender. Ask me:
1. **Which implementation?** Python (uv) or TypeScript (bun) 2. **Installation scope?** Project-only or user-wide 3. **Which tools to monitor?** All recommended tools or let me select
Installation Steps
After gathering my preferences:
1. **Check prerequisites**
- For Python: Verify `uv` is installed (`which uv`)
- For TypeScript: Verify `bun` is installed (`which bun`)
2. **Copy hook files**
- Copy the appropriate hook implementation to my project or user config
- For project: `.claude/hooks/prompt-injection-defender/`
- For user-wide: `~/.claude/hooks/prompt-injection-defender/`
3. **Copy patterns.yaml**
- Place `patterns.yaml` alongside the hook script
- This file contains all detection patterns
4. **Update settings configuration**
- **IMPORTANT**: Check if `.claude/settings.local.json` exists first
- If `settings.local.json` exists, merge hooks into THAT file (it takes precedence over `settings.json`)
- If only `settings.json` exists, merge hooks there
- Use the template from `python-settings.json` or `typescript-settings.json`
- Adjust paths based on installation scope
- For user-wide: update `~/.claude/settings.json`
**Settings precedence (highest to lowest):** 1. `.claude/settings.local.json` (local project - overrides all below) 2. `.claude/settings.json` (project settings) 3. `~/.claude/settings.json` (user settings)
5. **Restart Claude Code**
- **CRITICAL**: Hooks are captured at session startup
- Tell the user they MUST restart Claude Code for hooks to take effect
- Exit the current session and start a new one
6. **Verify installation**
- After restart, run a quick test to ensure the hook is working
- Read a test file with known injection patterns
- Use `/hooks` command to verify hooks are loaded
Recommended Tool Configuration
Monitor these tools for prompt injection:
- `Read` - File contents
- `WebFetch` - Web page contents
- `Bash` - Command outputs
- `Grep` - Search results
- `Task` - Agent outputs
- `mcp__*` - All MCP tool outputs
After Installation
**IMPORTANT**: Tell the user to restart Claude Code! Hooks only load at startup.
Explain what will happen after restart:
- When Claude reads files, fetches web pages, or runs commands
- The hook will scan the output for injection patterns
- If patterns are detected, Claude will see a warning
- Processing continues but Claude is warned to be cautious
The user can verify hooks are active by running `/hooks` in Claude Code.
Reference Files
- Skill location: `.claude/skills/prompt-injection-defender/`
- Python hook: `hooks/defender-python/post-tool-defender.py`
- TypeScript hook: `hooks/defender-typescript/post-tool-defender.ts`
- Patterns: `patterns.yaml`
- Settings templates: `python-settings.json` / `typescript-settings.json`
A collection of security and utility hooks for Claude Code. Hooks allow you to extend Claude Code's behavior by running custom scripts at key points during execution.
Repo: lasso-security/claude-hooks