hookify-rules

affaan-m ｜ 安全護欄 ｜ 原文 ｜ MIT

寫 hookify 規則，用 regex 比對事件並對 agent 警告或阻擋

---
name: hookify-rules
description: 建立與設定 hookify 規則：用帶 YAML frontmatter 的 markdown 檔，透過 regex 或條件比對 bash、檔案、prompt 或 stop 事件，並對 agent 顯示警告或阻擋訊息。建立 hookify 規則、撰寫 hook 規則語法、設定 hookify，或加入樣式護欄（例如阻擋危險指令、編輯 .env、除錯用程式碼）時使用。
---

# Writing Hookify Rules

## Overview

ECC 用內建的 Node runtime 來評估專案本地的 Hookify 規則。啟用 ECC hook 之後，
不需要另外安裝 Hookify plugin 或 Python。

Hookify 規則是帶 YAML frontmatter 的 markdown 檔，定義要監看的樣式，以及樣式比對到時要顯示的訊息。規則存放在 `.claude/hookify.{rule-name}.local.md` 檔案裡。

## Rule File Format

### Basic Structure

```markdown
---
name: rule-identifier
enabled: true
event: bash|file|stop|prompt|all
pattern: regex-pattern-here
---

Message to show Claude when this rule triggers.
Can include markdown formatting, warnings, suggestions, etc.
```

### Frontmatter Fields

| Field | Required | Values | Description |
|-------|----------|--------|-------------|
| name | Yes | kebab-case string | 唯一識別碼（動詞開頭：warn-*、block-*、require-*） |
| enabled | Yes | true/false | 不用刪除就能開關 |
| event | Yes | bash/file/stop/prompt/all | 由哪個 hook 事件觸發 |
| action | No | warn/block | warn（預設）只顯示訊息；block 會阻止該操作 |
| pattern | Yes* | regex string | 要比對的樣式（*複雜規則可改用 conditions） |

### Advanced Format (Multiple Conditions)

```markdown
---
name: warn-env-api-keys
enabled: true
event: file
conditions:
  - field: file_path
    operator: regex_match
    pattern: \.env$
  - field: new_text
    operator: contains
    pattern: API_KEY
---

You're adding an API key to a .env file. Ensure this file is in .gitignore!
```

**各事件可用的條件欄位：**
- bash：`command`
- file：`file_path`、`new_text`、`old_text`、`content`
- prompt：`user_prompt`

**運算子：** `regex_match`、`contains`、`equals`、`not_contains`、`starts_with`、`ends_with`

所有條件都要符合，規則才會觸發。

## Event Type Guide

### bash Events
比對 Bash 指令的樣式：
- 危險指令：`rm\s+-rf`、`dd\s+if=`、`mkfs`
- 提權：`sudo\s+`、`su\s+`
- 權限問題：`chmod\s+777`

### file Events
比對 Edit/Write/MultiEdit 操作：
- 除錯用程式碼：`console\.log\(`、`debugger`
- 安全風險：`eval\(`、`innerHTML\s*=`
- 敏感檔案：`\.env$`、`credentials`、`\.pem$`

### stop Events
完成度檢查和提醒。樣式 `.*` 永遠會比對成功。

### prompt Events
比對使用者 prompt 的內容，用來強制執行工作流程。

## Pattern Writing Tips

### Regex Basics
- 特殊字元要跳脫：`.` 寫成 `\.`，`(` 寫成 `\(`
- `\s` 空白字元，`\d` 數字，`\w` 單字字元
- `+` 一個以上，`*` 零個以上，`?` 可有可無
- `|` OR 運算子

### Common Pitfalls
- **太寬**：`log` 會比對到 "login"、"dialog"，要用 `console\.log\(`
- **太窄**：`rm -rf /tmp`，要用 `rm\s+-rf`
- **YAML 跳脫**：用不加引號的樣式；加引號的字串要寫 `\\s`

### Testing
```bash
python3 -c "import re; print(re.search(r'your_pattern', 'test text'))"
```

避免巢狀量詞，例如 `(a+)+`。Runtime 會拒絕有常見災難性回溯形狀的樣式，
因為規則是在 hook 路徑上同步執行的，而且每次 regex 評估都有 25 ms 的硬性 timeout。
無效、是 symlink 或過大的本地規則會 fail open 並輸出
診斷訊息，不會讓其他 Hookify 規則一起失效。

被 git 追蹤的本地規則預設是停用的。要先審查過那些檔案，才設定
`ECC_HOOKIFY_ALLOW_TRACKED=1`；在本地建立、被 gitignore 的一般規則，
不需要這個覆寫就會保持啟用。

## Runtime Behavior

- `warn` 會把訊息當成該事件專屬的額外 context 注入，不會阻擋。
- `block` 會在執行前拒絕符合條件的 Bash、PowerShell、Write、Edit 或 MultiEdit 呼叫。
- 在 prompt、post-tool 和 stop 事件上，`block` 使用 Claude Code 的結構化 block decision。
- Stop 規則會跳過遞迴的 `stop_hook_active` 事件，避免無限繼續的迴圈。

## File Organization

- **位置**：專案根目錄下的 `.claude/` 資料夾
- **命名**：`.claude/hookify.{descriptive-name}.local.md`
- **Gitignore**：把 `.claude/*.local.md` 加進 `.gitignore`

## Commands

- `/hookify [description]` - 建立新規則（沒給參數就自動分析對話）
- `/hookify-list` - 用表格列出所有規則
- `/hookify-configure` - 用互動方式開關規則
- `/hookify-help` - 完整文件

## Quick Reference

最精簡可用的規則：
```markdown
---
name: my-rule
enabled: true
event: bash
pattern: dangerous_command
---
Warning message here
```

---
name: hookify-rules
description: Create and configure hookify rules — markdown files with YAML frontmatter that match bash, file, prompt, or stop events by regex or conditions and show warn/block messages to the agent. Use when creating a hookify rule, writing hook rule syntax, configuring hookify, or adding pattern guardrails such as blocking dangerous commands, .env edits, or debug code.
---

# Writing Hookify Rules

## Overview

ECC evaluates project-local Hookify rules with its built-in Node runtime. No
separate Hookify plugin or Python installation is required when ECC hooks are
enabled.

Hookify rules are markdown files with YAML frontmatter that define patterns to watch for and messages to show when those patterns match. Rules are stored in `.claude/hookify.{rule-name}.local.md` files.

## Rule File Format

### Basic Structure

```markdown
---
name: rule-identifier
enabled: true
event: bash|file|stop|prompt|all
pattern: regex-pattern-here
---

Message to show Claude when this rule triggers.
Can include markdown formatting, warnings, suggestions, etc.
```

### Frontmatter Fields

| Field | Required | Values | Description |
|-------|----------|--------|-------------|
| name | Yes | kebab-case string | Unique identifier (verb-first: warn-*, block-*, require-*) |
| enabled | Yes | true/false | Toggle without deleting |
| event | Yes | bash/file/stop/prompt/all | Which hook event triggers this |
| action | No | warn/block | warn (default) shows message; block prevents operation |
| pattern | Yes* | regex string | Pattern to match (*or use conditions for complex rules) |

### Advanced Format (Multiple Conditions)

```markdown
---
name: warn-env-api-keys
enabled: true
event: file
conditions:
  - field: file_path
    operator: regex_match
    pattern: \.env$
  - field: new_text
    operator: contains
    pattern: API_KEY
---

You're adding an API key to a .env file. Ensure this file is in .gitignore!
```

**Condition fields by event:**
- bash: `command`
- file: `file_path`, `new_text`, `old_text`, `content`
- prompt: `user_prompt`

**Operators:** `regex_match`, `contains`, `equals`, `not_contains`, `starts_with`, `ends_with`

All conditions must match for rule to trigger.

## Event Type Guide

### bash Events
Match Bash command patterns:
- Dangerous commands: `rm\s+-rf`, `dd\s+if=`, `mkfs`
- Privilege escalation: `sudo\s+`, `su\s+`
- Permission issues: `chmod\s+777`

### file Events
Match Edit/Write/MultiEdit operations:
- Debug code: `console\.log\(`, `debugger`
- Security risks: `eval\(`, `innerHTML\s*=`
- Sensitive files: `\.env$`, `credentials`, `\.pem$`

### stop Events
Completion checks and reminders. Pattern `.*` matches always.

### prompt Events
Match user prompt content for workflow enforcement.

## Pattern Writing Tips

### Regex Basics
- Escape special chars: `.` to `\.`, `(` to `\(`
- `\s` whitespace, `\d` digit, `\w` word char
- `+` one or more, `*` zero or more, `?` optional
- `|` OR operator

### Common Pitfalls
- **Too broad**: `log` matches "login", "dialog" — use `console\.log\(`
- **Too specific**: `rm -rf /tmp` — use `rm\s+-rf`
- **YAML escaping**: Use unquoted patterns; quoted strings need `\\s`

### Testing
```bash
python3 -c "import re; print(re.search(r'your_pattern', 'test text'))"
```

Avoid nested quantifiers such as `(a+)+`. The runtime rejects patterns with
common catastrophic-backtracking shapes because rules run synchronously in the
hook path, and every regex evaluation has a 25 ms hard timeout. Invalid,
symlinked, or oversized local rules fail open and emit a
diagnostic without disabling other Hookify rules.

Git-tracked local rules are disabled by default. Set
`ECC_HOOKIFY_ALLOW_TRACKED=1` only after reviewing those files; ordinary
gitignored rules created locally remain active without that override.

## Runtime Behavior

- `warn` injects the message as event-specific additional context and does not block.
- `block` denies matching Bash, PowerShell, Write, Edit, or MultiEdit calls before execution.
- On prompt, post-tool, and stop events, `block` uses Claude Code's structured block decision.
- Stop rules skip recursive `stop_hook_active` events to prevent infinite continuation loops.

## File Organization

- **Location**: `.claude/` directory in project root
- **Naming**: `.claude/hookify.{descriptive-name}.local.md`
- **Gitignore**: Add `.claude/*.local.md` to `.gitignore`

## Commands

- `/hookify [description]` - Create new rules (auto-analyzes conversation if no args)
- `/hookify-list` - View all rules in table format
- `/hookify-configure` - Toggle rules on/off interactively
- `/hookify-help` - Full documentation

## Quick Reference

Minimum viable rule:
```markdown
---
name: my-rule
enabled: true
event: bash
pattern: dangerous_command
---
Warning message here
```