Rule to Hook Converter Command

Command

/rule-to-hook

Description

Analyzes rules written in CLAUDE.md (or similar instruction files) and converts them into deterministic Claude Code hooks. Rules in CLAUDE.md are advisory -- Claude might forget them during long sessions or after compaction. Hooks are enforced programmatically and cannot be bypassed.

Behavior

Arguments

• $ARGUMENTS -- Specific rule to convert, or empty to analyze all rules in CLAUDE.md

Conversion Process

1. Parse CLAUDE.md for enforceable rules:

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   # Rules found in CLAUDE.md:
   - "Never push directly to main"
   - "Always run tests before committing"
   - "Don't modify .env files"
   - "Use pnpm, not npm"
   - "Format code with Prettier after editing"

2. Classify each rule by enforcement type:

   Rule	Hook Type	Matcher	Enforceability
   Never push to main	PreToolUse	Bash	High -- can check git push commands
   Run tests before commit	Stop	agent	Medium -- can run tests before stopping
   Don't modify .env	PreToolUse	Edit/Write	High -- can check file paths
   Use pnpm not npm	PreToolUse	Bash	High -- can check for npm commands
   Format with Prettier	PostToolUse	Edit/Write	High -- can run formatter

3. Generate hooks for each convertible rule:

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   {
     "hooks": {
       "PreToolUse": [
         {
           "matcher": "Bash",
           "hooks": [
             {
               "type": "command",
               "command": "bash -c 'CMD=$(jq -r .tool_input.command); if echo \"$CMD\" | grep -qE \"git push.*(main|master)\"; then echo \"BLOCKED: No direct push to main\" >&2; exit 2; fi'"
             }
           ]
         },
         {
           "matcher": "Bash",
           "hooks": [
             {
               "type": "command",
               "command": "bash -c 'CMD=$(jq -r .tool_input.command); if echo \"$CMD\" | grep -qE \"^npm \"; then echo \"BLOCKED: Use pnpm instead of npm\" >&2; exit 2; fi'"
             }
           ]
         },
         {
           "matcher": "Edit|Write",
           "hooks": [
             {
               "type": "command",
               "command": "bash -c 'FILE=$(jq -r .tool_input.file_path); if [[ \"$FILE\" == *.env* ]]; then echo \"BLOCKED: Cannot modify .env files\" >&2; exit 2; fi'"
             }
           ]
         }
       ],
       "PostToolUse": [
         {
           "matcher": "Edit|Write",
           "hooks": [
             {
               "type": "command",
               "command": "jq -r '.tool_input.file_path' | xargs npx prettier --write 2>/dev/null || true"
             }
           ]
         }
       ]
     }
   }

4. Report unconvertible rules:

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   ### Rules That Cannot Be Automated
   | Rule | Reason |
   |------|--------|
   | "Write clean, readable code" | Subjective, no deterministic check |
   | "Follow the team's coding style" | Too vague to enforce programmatically |

Output Format

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## Rule to Hook Conversion

### Converted (4 rules -> 5 hooks)
- "Never push to main" -> PreToolUse/Bash hook
- "Don't modify .env" -> PreToolUse/Edit|Write hook
- "Use pnpm" -> PreToolUse/Bash hook
- "Format with Prettier" -> PostToolUse/Edit|Write hook

### Not Convertible (2 rules)
- "Write clean code" -- Subjective, keep in CLAUDE.md
- "Consider performance" -- Requires human judgment

### Generated Configuration
(merged JSON ready to paste into settings.json)

Examples

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# Convert all rules from CLAUDE.md
/rule-to-hook

# Convert a specific rule
/rule-to-hook never use npm, always use pnpm

# Convert rules from a different file
/rule-to-hook --file=.claude/team-rules.md