Hook Gen

/hook-gen — Natural Language Hook Generator

Convert plain English behavior descriptions into ready-to-use Claude Code hook configurations.

Instructions

Step 1: Parse the Request

From $ARGUMENTS or user message, extract:

• Trigger: When should this hook fire? (tool use, prompt submit, session events)
• Condition: What pattern to match? (file types, commands, content)
• Action: What should happen? (block, warn, log, transform, suggest)

If the description is ambiguous, ask ONE clarifying question with a recommended answer.

Step 2: Map to Hook Event

Step 3: Generate Hook Script

Create a shell script following this template:

#!/usr/bin/env bash
# Hook: {{HOOK_NAME}}
# Trigger: {{EVENT}} ({{MATCHER}})
# {{DESCRIPTION}}

# No set -euo pipefail — hooks must be resilient on Windows

# Hook profile gate
export HOOK_NAME="{{hook-name}}"; export HOOK_MIN_PROFILE="standard"
source "${HOME}/.claude/lib/hook-gate.sh" 2>/dev/null || true

INPUT=$(cat 2>/dev/null) || true
[ -z "$INPUT" ] && exit 0

# Parse input via node (cross-platform, no jq)
{{PARSING_LOGIC}}

# {{ACTION_LOGIC}}

exit 0

Step 4: Generate settings.json Entry

Output the hook configuration in settings.json format:

{
  "hooks": {
    "{{EVENT}}": [
      {
        "matcher": "{{MATCHER}}",
        "hooks": [
          {
            "type": "command",
            "command": "bash ~/.claude/hooks/{{hook-name}}.sh"
          }
        ]
      }
    ]
  }
}

Step 5: Output

Present both the script and settings.json entry. Then ask:

1. "Save to ~/.claude/hooks/{{hook-name}}.sh?"
2. "Add to ~/.claude/settings.json?"

Examples

Rules

• Always use node -e for JSON parsing (no jq)
• Always include the hook-gate.sh integration
• Never use set -euo pipefail (breaks on Windows Git Bash)
• Output must be valid JSON for the blocking path (hookSpecificOutput format)
• Default profile level: standard (suggest minimal only for safety-critical hooks)