# API Standardization Module Changelog

All notable changes to the API Standardization module will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [1.0.0] - 2025-01-01

### Added
- **REST API Framework** (`rest_api.py`):
  - Complete REST API implementation with routing and middleware
  - HTTP method support (GET, POST, PUT, DELETE, PATCH, OPTIONS, HEAD)
  - Structured request/response objects with JSON handling
  - Router composition for modular API design
  - Path parameter extraction and query string parsing
  - Comprehensive error handling with appropriate HTTP status codes
  - Request/response metrics collection

- **GraphQL API Framework** (`graphql_api.py`):
  - GraphQL schema definition with object types and fields
  - Resolver registration and execution
  - Mutation support with input/output type validation
  - Query complexity analysis and limits
  - Schema Definition Language (SDL) generation
  - Built-in scalar types (String, Int, Float, Boolean, ID)
  - Error handling and validation

- **API Versioning System** (`api_versioning.py`):
  - Multiple version format support (Semantic, Date, Integer)
  - Version compatibility checking and migration paths
  - Request-based version detection (headers, query params, Accept header)
  - Versioned endpoint management
  - Deprecation handling and warnings
  - Data migration between API versions

- **OpenAPI Specification Generator** (`openapi_generator.py`):
  - Automatic OpenAPI 3.0.3 specification generation
  - REST API endpoint discovery and documentation
  - GraphQL API schema conversion to OpenAPI
  - Version information integration
  - Security scheme definitions
  - JSON and YAML output formats
  - Specification validation and error reporting

- **Comprehensive Type System**:
  - Strongly typed interfaces throughout
  - Dataclasses for structured data
  - Enums for HTTP methods, status codes, and version formats
  - Type hints for all public APIs

- **Testing Suite** (`src/codomyrmex/tests/unit/test_api_standardization.py`):
  - Unit tests for all components
  - Integration tests combining multiple components
  - Mock-based testing for external dependencies
  - Comprehensive test coverage for error conditions

- **Documentation**:
  - Complete README with usage examples
  - API specification document with all interfaces
  - Integration examples for real-world usage
  - Architecture documentation

### Technical Details

#### REST API Implementation
- Router-based architecture with prefix support
- Middleware pipeline with short-circuiting
- Automatic content-type handling
- Path parameter regex compilation and caching
- Request context propagation

#### GraphQL Implementation
- Simplified query parsing (ready for full parser integration)
- Resolver complexity calculation
- Type system with field requirements
- Mutation input/output validation
- SDL generation for schema inspection

#### Versioning Implementation
- Semantic version parsing and comparison
- Migration rule registration and execution
- Header-based version detection
- Backward compatibility enforcement

#### OpenAPI Generation
- REST endpoint to OpenAPI operation conversion
- GraphQL type to OpenAPI schema mapping
- Component reuse and reference generation
- Validation against OpenAPI specification

### Dependencies
- Standard library only (no external dependencies)
- Compatible with Python 3.8+
- Logging integration with Codomyrmex logging system

### Performance Characteristics
- REST routing: O(1) for direct matches, O(path_segments) for parameterized routes
- GraphQL execution: O(query_complexity) with configurable limits
- OpenAPI generation: O(number_of_endpoints + number_of_types)
- Memory usage: Linear scaling with number of endpoints and types

### Security Considerations
- Input validation for all user-provided data
- SQL injection protection through parameterized queries (when integrated)
- XSS protection through proper content-type handling
- Authentication middleware hooks
- Rate limiting preparation

### Future Enhancements (Not Included in 1.0.0)
- Full GraphQL parser integration
- WebSocket subscriptions for GraphQL
- Advanced caching strategies
- API gateway integration
- Monitoring and metrics dashboard
- Advanced security features (OAuth, JWT)
- API documentation hosting
- Client SDK generation

### Breaking Changes
- None (initial release)

### Bug Fixes
- None (initial release)

### Contributors
- Codomyrmex Development Team

### Acknowledgments
- Based on REST API best practices
- GraphQL specification compliance
- OpenAPI 3.0.3 specification adherence
- Semantic versioning standards

## Navigation Links

- **Parent**: [Project Overview](../README.md)
- **Module Index**: [All Agents](../../AGENTS.md)
- **Documentation**: [Reference Guides](../../../../docs/README.md)
- **Home**: [Root README](../../../README.md)
