# Comprehensive Coding Standards for LLM Projects

**Version:** 1.0.0
**Last Updated:** 2025-01-13
**Status:** Active
**Standard Code:** CS

---

## Table of Contents

1. [Code Style and Formatting](#1-code-style-and-formatting)
2. [Documentation Standards](#2-documentation-standards)
3. [Architecture and Design Patterns](#3-architecture-and-design-patterns)
4. [Security Best Practices](#4-security-best-practices)
5. [Performance Optimization](#5-performance-optimization)
6. [Error Handling](#6-error-handling)
7. [Resource Management](#7-resource-management)
8. [Dependency Management](#8-dependency-management)
9. [Version Control Practices](#9-version-control-practices)
10. [Code Review Standards](#10-code-review-standards)
11. [Accessibility Standards](#11-accessibility-standards)
12. [Internationalization & Localization](#12-internationalization--localization)
13. [Concurrency and Parallelism](#13-concurrency-and-parallelism)
14. [API Design](#14-api-design)
15. [Refactoring Guidelines](#15-refactoring-guidelines)
16. [Sustainability and Green Coding](#16-sustainability-and-green-coding)

## Overview

This standard provides comprehensive guidelines and best practices for the subject area.
It aims to ensure consistency, quality, and maintainability across all related implementations.

Beyond testing, establishing clear coding standards is essential for maintaining
high-quality, consistent, and maintainable software. Here's a comprehensive set
of coding standards you should provide for LLM coding projects:

## 1. Code Style and Formatting

```text
Implement consistent code style and formatting:

1. Follow established style guides for your language:
   - Python: PEP 8
   - JavaScript: Airbnb/Standard/Google
   - Java: Google Java Style Guide
   - Go: gofmt standard

2. Enforce consistent formatting:
   - Indentation (spaces vs tabs, amount)
   - Line length (80-120 characters)
   - Statement termination conventions
   - Bracket placement
   - Whitespace usage

3. Use meaningful naming conventions:
   - Classes: PascalCase descriptive nouns
   - Functions/methods: camelCase or snake_case verbs
   - Variables: camelCase or snake_case nouns
   - Constants: UPPER_SNAKE_CASE
   - Private members: prefix with underscore
   - Avoid potentially offensive or ambiguous acronyms
   - Always consider cultural sensitivity in naming
   - Prefer full descriptive names over unclear abbreviations

4. Structure code consistently:
   - Organize imports logically
   - Group related functions/methods
   - Maintain consistent file organization
   - Limit file size (max 300-500 lines)
   - Limit function size (max 50 lines)

5. Automate style enforcement:
   - Use linters (pylint, ESLint, etc.)
   - Apply formatters (black, prettier, etc.)
   - Configure pre-commit hooks
   - Integrate into CI/CD pipelines
```

## 2. Documentation Standards

```text
Implement comprehensive documentation standards:

1. Include documentation for all public interfaces:
   - Function/method purpose and behavior
   - Parameter descriptions and types
   - Return value descriptions and types
   - Exceptions/errors thrown
   - Usage examples for complex functions

2. Add contextual documentation:
   - Module/file-level documentation
   - Class-level documentation
   - Complex algorithm explanations
   - Rationale for non-obvious decisions

3. Follow documentation format standards:
   - Use consistent docstring format (JSDoc, doctest, etc.)
   - Include parameter types (typing)
   - Document side effects
   - Note thread safety considerations
   - Specify performance characteristics when relevant

4. Maintain system-level documentation:
   - Architecture diagrams
   - Component interaction flows
   - Data models and relationships
   - API documentation
   - Deployment requirements

5. Establish documentation review process:
   - Review docs during code reviews
   - Test docs for accuracy
   - Update docs when code changes
   - Track documentation coverage
   - Validate examples work as documented
```

## 3. Architecture and Design Patterns

```text
Implement architectural standards and design patterns:

1. Establish clear architectural boundaries:
   - Define layers (presentation, business, data)
   - Enforce separation of concerns
   - Implement dependency inversion
   - Establish clear module responsibilities
   - Document architectural decisions

2. Apply appropriate design patterns:
   - Creational patterns (Factory, Builder, etc.)
   - Structural patterns (Adapter, Decorator, etc.)
   - Behavioral patterns (Observer, Strategy, etc.)
   - Concurrency patterns where needed
   - Domain-specific patterns when applicable

3. Follow SOLID principles:
   - Single Responsibility Principle
   - Open/Closed Principle
   - Liskov Substitution Principle
   - Interface Segregation Principle
   - Dependency Inversion Principle

4. Design for extensibility:
   - Use interfaces over implementations
   - Design plugin systems where appropriate
   - Define extension points
   - Avoid tight coupling
   - Implement feature toggles for optional features

5. Establish system boundaries:
   - Define clear APIs between components
   - Implement proper encapsulation
   - Use domain-driven design where applicable
   - Document system constraints and assumptions
   - Catalog technical debt with remediation plans
```

## 4. Security Best Practices

```text
Implement security best practices in all code:

1. Apply input validation:
   - Validate all user input at entry points
   - Sanitize data before processing
   - Implement parameterized queries
   - Use safe parsers for structured data
   - Enforce type safety

2. Implement proper authentication:
   - Follow OAuth 2.0/OpenID Connect for auth flows
   - Store credentials securely (hashing, encryption)
   - Apply MFA where appropriate
   - Implement proper session management
   - Use secure password policies

3. Apply appropriate authorization:
   - Implement RBAC or ABAC models
   - Perform authorization checks at each layer
   - Apply principle of least privilege
   - Use capability-based security where appropriate
   - Audit authorization decisions

4. Protect sensitive data:
   - Encrypt data at rest and in transit
   - Implement proper key management
   - Minimize sensitive data collection
   - Apply data retention policies
   - Implement secure logging practices

5. Apply secure coding practices:
   - Use secure defaults
   - Implement proper error handling
   - Apply memory safety techniques
   - Follow secure dependency practices
   - Use security headers in web applications
```

### NIST Control Tagging

When implementing security features, add NIST 800-53r5 control tags:

```python
# @nist ia-2 "User authentication"
def authenticate_user(credentials: Credentials) -> User:
    """Authenticate user with provided credentials."""
    pass

# @nist ac-3 "Access enforcement"
# @nist ac-6 "Least privilege"
def check_permissions(user: User, resource: Resource) -> bool:
    """Check if user has permission to access resource."""
    pass
```

**Common Security Pattern → NIST Control Mappings:**

- Authentication code → `@nist ia-2`, `@nist ia-5`
- Authorization logic → `@nist ac-3`, `@nist ac-6`
- Password handling → `@nist ia-5`, `@nist ia-5.1`
- Session management → `@nist ac-12`
- Encryption → `@nist sc-8` (transit), `@nist sc-13` (at rest)
- Audit logging → `@nist au-2`, `@nist au-3`
- Input validation → `@nist si-10`
- Error handling → `@nist si-11`

See [NIST_IMPLEMENTATION_GUIDE.md](../nist/NIST_IMPLEMENTATION_GUIDE.md) for:

- Complete control mappings
- Language-specific syntax
- Automated tooling
- CI/CD integration

## 5. Performance Optimization

```text
Implement performance standards:

1. Establish performance targets:
   - Define response time goals
   - Set throughput requirements
   - Specify resource utilization limits
   - Document latency targets
   - Define scaling characteristics

2. Apply algorithmic efficiency:
   - Use appropriate data structures
   - Select optimal algorithms for common operations
   - Analyze time and space complexity
   - Avoid O(n²) or higher algorithms for large datasets
   - Apply memoization for expensive calculations

3. Implement resource optimization:
   - Use connection pooling
   - Apply caching strategically
   - Implement proper memory management
   - Optimize I/O operations
   - Use asynchronous processing where appropriate

4. Apply database optimization:
   - Design efficient schemas
   - Use appropriate indexes
   - Write optimized queries
   - Implement query caching
   - Use database-specific optimization features

5. Implement proper benchmarking:
   - Create automated performance tests
   - Measure against established baselines
   - Track performance metrics over time
   - Profile code regularly
   - Apply continuous performance monitoring
```

## 6. Error Handling

```text
Implement robust error handling standards:

1. Define error handling strategy:
   - Distinguish between recoverable and non-recoverable errors
   - Establish exception hierarchies
   - Define retry policies
   - Document error handling behavior
   - Specify error reporting requirements

2. Implement defensive programming:
   - Check preconditions
   - Validate method arguments
   - Handle edge cases explicitly
   - Design for failure
   - Use assertions for invariant conditions

3. Create informative error messages:
   - Include context information
   - Add troubleshooting guidance
   - Use consistent error formatting
   - Include error codes or identifiers
   - Localize error messages

4. Apply proper exception handling:
   - Catch specific exceptions
   - Avoid empty catch blocks
   - Maintain exception context
   - Clean up resources properly
   - Log sufficient information

5. Implement structured logging:
   - Log errors with stack traces
   - Include correlation IDs
   - Use appropriate severity levels
   - Implement context-aware logging
   - Avoid logging sensitive information
```

## 7. Resource Management

```text
Implement effective resource management:

1. Apply proper resource lifecycle management:
   - Acquire resources at the latest possible moment
   - Release resources at the earliest possible moment
   - Use resource pooling where appropriate
   - Implement timeout policies
   - Apply circuit breakers for external resources

2. Handle external dependencies gracefully:
   - Implement fallback mechanisms
   - Apply progressive degradation
   - Use bulkheading to isolate failures
   - Implement health checks
   - Design for partial availability

3. Implement proper concurrency control:
   - Use appropriate locking mechanisms
   - Apply thread synchronization
   - Prevent deadlocks and race conditions
   - Implement proper thread/connection pooling
   - Use non-blocking algorithms where possible

4. Manage memory efficiently:
   - Implement proper cleanup
   - Avoid memory leaks
   - Apply resource limits
   - Use weak references where appropriate
   - Profile memory usage regularly

5. Optimize file and network operations:
   - Buffer I/O operations appropriately
   - Use non-blocking I/O when beneficial
   - Apply connection pooling
   - Implement request batching
   - Use streaming for large datasets
```

## 8. Dependency Management

```text
Implement dependency management standards:

1. Define dependency selection criteria:
   - Evaluate license compatibility
   - Assess security history
   - Check maintenance status
   - Consider community size
   - Verify compatibility with other components

2. Implement version pinning:
   - Lock direct dependencies
   - Specify version ranges appropriately
   - Document version selection rationale
   - Update dependencies on a regular schedule
   - Automate dependency updates when possible

3. Apply dependency isolation:
   - Use virtual environments
   - Implement containerization
   - Apply dependency injection
   - Manage transitive dependencies
   - Minimize dependency footprint

4. Implement vulnerability scanning:
   - Integrate dependency scanning in CI/CD
   - Subscribe to security advisories
   - Apply automatic updates for security patches
   - Maintain a dependencies inventory
   - Document mitigation strategies for vulnerabilities

5. Create dependency documentation:
   - Document purpose of each dependency
   - Map dependencies to features
   - Maintain alternatives analysis
   - Document upgrade paths
   - Catalog custom patches
```

## 9. Version Control Practices

```text
Implement effective version control standards:

1. Define branch management strategy:
   - Implement trunk-based or GitFlow approaches
   - Define naming conventions for branches
   - Establish branch lifetime policies
   - Document merge requirements
   - Specify branch protection rules

2. Create commit standards:
   - Write descriptive commit messages
   - Use conventional commits format
   - Include issue/ticket references
   - Make atomic, focused commits
   - Sign commits when applicable

3. Implement code review workflows:
   - Require pull/merge requests for changes
   - Define review criteria
   - Establish number of required approvers
   - Automate preliminary reviews
   - Document review responsibilities

4. Apply versioning standards:
   - Use semantic versioning
   - Document breaking changes
   - Maintain change logs
   - Tag releases
   - Archive release artifacts

5. Establish repository hygiene:
   - Configure appropriate .gitignore files
   - Define artifact storage strategy
   - Document repository structure
   - Implement hook scripts
   - Maintain repository documentation
```

## 10. Code Review Standards

```text
Implement comprehensive code review standards:

1. Define review scope:
   - Functionality correctness
   - Code style and standards adherence
   - Security considerations
   - Performance implications
   - Documentation completeness

2. Establish review process:
   - Specify required reviewers
   - Define maximum review size
   - Set review timeframes
   - Implement pre-review checklists
   - Document review roles

3. Apply technical review criteria:
   - Check algorithm correctness
   - Review error handling
   - Examine test coverage
   - Assess maintainability
   - Verify compatibility

4. Implement review automation:
   - Automate style checks
   - Apply static analysis
   - Verify build and tests pass
   - Check documentation coverage
   - Generate code quality metrics

5. Foster constructive review culture:
   - Focus on code, not authors
   - Provide specific, actionable feedback
   - Explain reasoning for suggestions
   - Ask questions instead of making demands
   - Acknowledge good implementations
```

## 11. Accessibility Standards

```text
Implement accessibility standards:

1. Apply semantic structure:
   - Use appropriate HTML elements
   - Implement proper heading hierarchy
   - Apply ARIA roles and attributes
   - Provide descriptive labels
   - Ensure keyboard navigability

2. Implement responsive design:
   - Support various screen sizes
   - Ensure touch-friendly targets
   - Apply flexible layouts
   - Implement responsive images
   - Test on multiple devices

3. Apply color and contrast standards:
   - Meet WCAG contrast requirements
   - Do not rely on color alone for information
   - Provide focus indicators
   - Support high contrast modes
   - Test with color blindness simulators

4. Implement assistive technology support:
   - Add alt text for images
   - Provide transcripts for audio
   - Add captions for video
   - Support screen readers
   - Test with assistive technologies

5. Apply accessibility testing:
   - Use automated accessibility checkers
   - Perform manual keyboard testing
   - Test with screen readers
   - Include accessibility in QA
   - Document accessibility features
```

## 12. Internationalization & Localization

```text
Implement internationalization and localization standards:

1. Apply proper text externalization:
   - Extract user-facing strings
   - Avoid concatenating strings
   - Use string templates with parameters
   - Support pluralization rules
   - Handle gender-specific text

2. Implement locale awareness:
   - Support different date/time formats
   - Apply locale-specific number formatting
   - Handle different currencies
   - Support text directionality (RTL)
   - Apply locale-specific sorting

3. Design for text expansion:
   - Allow UI elements to expand
   - Avoid fixed-width text containers
   - Test with longer languages
   - Handle dynamic text layout
   - Support different character sets

4. Implement resource management:
   - Organize resources by locale
   - Support resource fallbacks
   - Apply efficient resource loading
   - Implement locale switching
   - Document translation workflow

5. Apply localization testing:
   - Test with pseudo-localization
   - Verify all supported locales
   - Test bidirectional text support
   - Validate cultural appropriateness
   - Include native speakers in testing
```

## 13. Concurrency and Parallelism

```text
Implement standards for concurrent and parallel code:

1. Define concurrency models:
   - Specify threading models
   - Document async/await patterns
   - Define actor-based approaches
   - Establish event-driven architectures
   - Document concurrent data access patterns

2. Implement thread safety:
   - Document thread-safety guarantees
   - Use thread-safe collections
   - Apply proper synchronization
   - Implement immutable objects where possible
   - Use atomic operations

3. Apply parallelism patterns:
   - Implement task parallelism
   - Apply data parallelism
   - Use pipeline parallelism
   - Define work distribution strategies
   - Document scale-out approaches

4. Manage shared resources:
   - Document resource contention points
   - Apply appropriate locks
   - Use lock-free algorithms when possible
   - Implement resource limits
   - Apply backpressure mechanisms

5. Test concurrent code:
   - Verify race condition handling
   - Test under load
   - Simulate slow resources
   - Apply fuzzing for concurrent operations
   - Document concurrency assumptions
```

## 14. API Design

```text
Implement API design standards:

1. Apply API design principles:
   - Design for consistency
   - Make APIs intuitive and discoverable
   - Follow principle of least surprise
   - Design for evolution
   - Document design decisions

2. Implement proper versioning:
   - Use semantic versioning
   - Support backward compatibility
   - Document breaking changes
   - Provide migration paths
   - Deprecate features gracefully

3. Define interface contracts:
   - Document expected behavior
   - Specify parameter constraints
   - Define error responses
   - Document side effects
   - Specify performance characteristics

4. Apply REST/GraphQL best practices:
   - Use appropriate HTTP methods
   - Apply consistent resource naming
   - Implement proper status codes
   - Design efficient queries
   - Support pagination and filtering

5. Implement API security:
   - Apply proper authentication
   - Implement authorization
   - Rate limit appropriately
   - Validate input thoroughly
   - Document security requirements
```

## 15. Refactoring Guidelines

```text
Implement refactoring standards:

1. Define refactoring triggers:
   - Code smells that warrant refactoring
   - Complexity thresholds
   - Performance bottlenecks
   - Technical debt indicators
   - Maintainability metrics

2. Establish refactoring processes:
   - Document current behavior
   - Create comprehensive tests
   - Apply small, incremental changes
   - Review refactored code thoroughly
   - Verify behavior preservation

3. Implement refactoring techniques:
   - Extract method/class
   - Consolidate conditional expressions
   - Replace inheritance with composition
   - Introduce design patterns
   - Simplify complex code

4. Apply refactoring tools:
   - Use IDE refactoring features
   - Apply automated refactoring
   - Implement static analysis
   - Track code quality metrics
   - Document refactoring history

5. Document refactoring outcomes:
   - Measure improvements
   - Update documentation
   - Record lessons learned
   - Track technical debt reduction
   - Document new patterns introduced
```

## 16. Sustainability and Green Coding

```text
Implement standards for sustainable and eco-friendly code:

1. Optimize resource efficiency:
   - Minimize CPU cycles for common operations
   - Reduce memory footprint
   - Optimize I/O operations
   - Apply lazy loading techniques
   - Implement efficient algorithms

2. Apply energy-aware design:
   - Batch background operations
   - Implement efficient polling strategies
   - Use push mechanisms over pull
   - Optimize for mobile battery usage
   - Document power consumption profiles

3. Implement efficient data practices:
   - Minimize data transfers
   - Apply appropriate compression
   - Implement caching strategies
   - Optimize image and media usage
   - Use efficient data formats

4. Design for hardware efficiency:
   - Support older/lower-spec devices
   - Implement progressive enhancement
   - Minimize CPU-intensive animations
   - Use hardware acceleration appropriately
   - Apply responsive design principles

5. Measure environmental impact:
   - Track energy consumption
   - Monitor carbon footprint
   - Apply green hosting options
   - Document sustainability improvements
   - Include efficiency in performance metrics
```

## Master Prompt for Coding Standards Implementation

```text
Generate code following these comprehensive coding standards:

1. Style and Structure:
   - Follow [language-specific] style guide conventions
   - Use meaningful, consistent naming
   - Document all public interfaces thoroughly
   - Limit function/method size to 50 lines
   - Apply consistent error handling

2. Architecture and Design:
   - Implement SOLID principles
   - Apply appropriate design patterns
   - Define clear component boundaries
   - Design testable components
   - Document architectural decisions

3. Security and Performance:
   - Validate all inputs thoroughly
   - Apply proper authentication/authorization
   - Optimize critical algorithms
   - Manage resources efficiently
   - Implement appropriate caching

4. Quality and Maintenance:
   - Create comprehensive tests
   - Document complex logic
   - Apply internationalization best practices
   - Implement accessibility standards
   - Design for extensibility

The code should be robust, efficient, secure, and maintainable. It should
follow all applicable industry best practices and demonstrate a high level of
craftsmanship.

## Implementation

### Getting Started

1. Review the relevant sections of this standard for your use case
2. Identify which guidelines apply to your project
3. Implement the required practices and patterns
4. Validate compliance using the provided checklists

### Implementation Checklist

- [ ] Review and understand applicable standards
- [ ] Implement required practices
- [ ] Follow recommended patterns
- [ ] Validate implementation against guidelines
- [ ] Document any deviations with justification

## Related Standards

- [Knowledge Management Standards](KNOWLEDGE_MANAGEMENT_STANDARDS.md) - Documentation standards
- [CREATING_STANDARDS_GUIDE.md](../guides/CREATING_STANDARDS_GUIDE.md) - How to create standards
- [COMPLIANCE_STANDARDS.md](COMPLIANCE_STANDARDS.md) - NIST compliance for secure coding
- [Model Context Protocol Standards](MODEL_CONTEXT_PROTOCOL_STANDARDS.md) - MCP implementation patterns
