# Changelog

All notable changes to the ATP™ SDK 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] - 2024-06-28

### Added

#### Core Features
- **ATPClient**: Main SDK client providing unified access to all ATP services
- **Service Clients**: Dedicated clients for Identity, Credentials, Permissions, Audit, and Gateway services
- **Authentication**: Multiple authentication methods including DID-based auth, JWT tokens, and MFA
- **TypeScript Support**: Complete TypeScript definitions and type safety

#### Identity Management
- DID generation, registration, and resolution
- Multi-factor authentication (TOTP, SMS, Email)
- Trust level management and verification
- Cryptographic key rotation and recovery
- Identity metadata and status management

#### Verifiable Credentials
- Credential schema creation and management
- Verifiable credential issuance and verification
- Verifiable presentation creation and validation
- Credential lifecycle management (suspend, revoke, reactivate)
- Credential status checking and revocation lists

#### Permissions & Access Control
- Policy-based access control (PBAC)
- Fine-grained permission management
- Capability token delegation
- Real-time access decision evaluation
- Permission analytics and audit trails

#### Audit & Compliance
- Comprehensive audit event logging
- Blockchain anchoring for immutable audit trails
- Advanced audit query and search capabilities
- Compliance reporting and data export
- Audit chain integrity verification

#### Real-time Features
- WebSocket event streaming with auto-reconnection
- Real-time security monitoring and alerts
- Service health monitoring and status checking
- Event filtering and processing
- Circuit breaker patterns for resilience

#### Developer Experience
- **Examples**: 7 comprehensive examples covering all major features
- **Documentation**: Complete API reference and implementation guides
- **Error Handling**: Structured error types with detailed error information
- **Testing**: Comprehensive test utilities and mocking support
- **Performance**: Connection pooling, caching, and batch operations

#### Utility Classes
- **CryptoUtils**: Ed25519 cryptographic operations, hashing, and key management
- **DIDUtils**: DID generation, parsing, validation, and document management
- **JWTUtils**: JWT creation, verification, and token lifecycle management

#### Configuration & Setup
- Environment-based configuration management
- Quick configuration helpers for development
- Production-ready security configurations
- Service discovery and load balancing support

### Technical Specifications
- **Node.js**: Requires Node.js 18+ with ES modules support
- **TypeScript**: Built with TypeScript 5.0+ for type safety
- **Dependencies**: Minimal dependencies with security-focused choices
- **Bundle Size**: Optimized for both browser and Node.js environments
- **Performance**: Designed for high-throughput production environments

### Security Features
- **End-to-End Encryption**: All communications use TLS/SSL
- **Signature Verification**: Cryptographic verification of all operations
- **Rate Limiting**: Built-in rate limiting and circuit breaker patterns
- **Input Validation**: Comprehensive input validation and sanitization
- **Secret Management**: Secure handling of private keys and tokens

### Standards Compliance
- **W3C DID Core**: Full compliance with W3C DID specification
- **W3C Verifiable Credentials**: Complete VC data model implementation
- **RFC 7519**: JWT token handling according to RFC standards
- **Security Best Practices**: Following OWASP and industry security guidelines

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## [Unreleased]

### Planned Features
- **v1.1.0**: WebAssembly support for browser environments
- **v1.2.0**: GraphQL API support and enhanced querying
- **v1.3.0**: Advanced zero-knowledge proof features
- **v2.0.0**: ATP Protocol v2 compatibility and new features

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## Development Notes

This initial release represents a complete implementation of the ATP™ SDK with all major features and comprehensive documentation. The SDK has been designed with production environments in mind, featuring robust error handling, performance optimizations, and security best practices.

For migration guides and upgrade instructions, see the [Migration Guide](./docs/guides/migration.md).

For detailed API documentation, see the [API Reference](./docs/api/README.md).

For implementation examples, see the [Examples](./examples/README.md) directory.