Rule Creator

Create effective user rules that customize AI behavior for projects and personal preferences.

What Are User Rules?

User rules are custom instructions that modify how the AI assistant behaves. They can define:

• Coding standards - Style, patterns, and conventions
• Language preferences - Response language, terminology
• Project configuration - Framework choices, file structure
• Workflow guidelines - Git, testing, documentation practices

Rule Creation Workflow

Step 1: Identify Rule Purpose

Ask the user:

1. What behavior do you want to modify?
2. Is this a project rule (shared) or personal preference?
3. Are there exceptions to this rule?

Step 2: Choose Rule Category

Common categories:

• coding-style - Code formatting, syntax preferences
• language - Response language, communication style
• project - Framework-specific, architecture decisions
• git - Commit messages, branching, PR guidelines
• naming - Variable, function, file naming conventions
• security - Authentication, secrets, input validation
• testing - Test coverage, naming, mocking practices
• documentation - Comments, README, JSDoc requirements

For templates and examples, see references/rule-patterns.md.

Step 3: Write the Rule

Follow these principles:

1. Be specific - Use concrete examples
2. Be actionable - Clear instructions, not vague guidance
3. Include examples - Show correct usage
4. Define exceptions - When the rule doesn't apply

For detailed writing guidelines, see references/best-practices.md.

Step 4: Format the Rule

Use this format:

## [Category]: [Short Title]

[Clear instruction in imperative form]

Example:
[Code or text example showing correct usage]

Exception: [When this rule doesn't apply, if any]

Step 5: Validate the Rule

Check against this list:

• Clear and unambiguous?
• Specific context defined?
• Actionable instruction?
• Example included (if complex)?
• Exceptions documented?
• No conflicts with existing rules?

Quick Templates

Coding Style Rule

## Coding: [Title]

[What to do and how to do it]

✅ Correct:
[good example]

❌ Avoid:
[bad example]

Project Configuration Rule

## Project: [Title]

Use [technology/pattern] for [purpose].

Configuration:
[relevant settings or file structure]

Workflow Rule

## Workflow: [Title]

[Step-by-step process or checklist]

1. [First step]
2. [Second step]
3. [Third step]

Managing Rules

Adding Rules

Create or append to the user's rules file. Group related rules under clear headers.

Updating Rules

When updating, preserve existing rules unless explicitly asked to replace them.

Organizing Rules

Suggest organizing rules by:

1. Priority (security > performance > style)
2. Category (coding, git, testing, etc.)
3. Scope (project-wide vs file-specific)

Output Location

Rules must be saved in the .agent/rules/ directory with one file per rule category:

.agent/rules/
├── git-commit.md          # Git commit format rules
├── coding-style.md        # Coding style rules
├── naming-conventions.md  # Naming rules
├── security.md            # Security rules
└── testing.md             # Testing rules

File Naming

• Use kebab-case: {rule-name}.md
• Name should reflect the rule category or purpose
• Examples: git-commit.md, coding-style.md, api-design.md

File Structure

Each rule file should include YAML frontmatter with activation mode, followed by the rule content:

---
activation: always_on  # or: manual, model_decision, glob
description: Brief description for model decision mode
globs: ["*.ts", "src/**/*.tsx"]  # only for glob activation
---

# [Rule Category Title]

Brief description of what this rule covers.

## Rule 1: [Title]

[Rule content with examples]

## Rule 2: [Title]

[Rule content with examples]

Activation Modes

Rules can be activated in different ways:

Mode	Frontmatter	Description
Manual	activation: manual	Activated via @mention in input (e.g., @git-commit)
Always On	activation: always_on	Always applied to all conversations
Model Decision	activation: model_decision	Model decides based on description field
Glob	activation: glob	Applied to files matching globs patterns

Examples

Always On (recommended for general rules):

---
activation: always_on
---

Manual (for specific workflows):

---
activation: manual
---

Model Decision (context-dependent):

---
activation: model_decision
description: Apply when working with git commits or version control
---

Glob (file-type specific):

---
activation: glob
globs: ["*.ts", "*.tsx", "src/**/*.js"]
---

@Mentions (File References)

Reference other files in rules using @filename:

Path Type	Example	Resolution
Relative	@../shared/common.md	Relative to rule file location
Absolute	@/docs/api.md	First tries true absolute path, then workspace-relative
Workspace	@app/types.ts	Relative to workspace/repository root

Use Cases

Referencing shared documentation:

For API conventions, see @/docs/api-guidelines.md

Including type definitions:

All API responses must follow the types in @app/types/api.types.ts

Linking related rules:

See also: @coding-style.md for naming conventions

Creating Rules

1. Check if .agent/rules/ directory exists, create if not
2. Check if a file for this category already exists
3. If exists: append new rules to the file
4. If not: create new file with proper structure