Changelog

All notable changes to the EventCore project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

Added

  • Comprehensive interactive documentation tutorials
  • Enhanced error diagnostics with miette integration
  • Fluent CommandExecutorBuilder API for configuration
  • Command definition macros for cleaner code
  • Multi-stream event sourcing with dynamic consistency boundaries
  • Type-safe command system with compile-time stream access control
  • Flexible command-controlled dynamic stream discovery
  • PostgreSQL adapter with full type safety
  • In-memory event store adapter for testing
  • Comprehensive benchmarking suite
  • Complete examples for banking, e-commerce, and saga pattern domains
  • Property-based testing throughout the codebase
  • Extensive monitoring and observability features
  • Projection system with checkpointing and recovery
  • Event serialization with schema evolution support
  • Command retry mechanisms with configurable policies
  • Developer experience improvements with macros
  • Complete CI/CD pipeline with PostgreSQL integration

Changed

  • Replaced aggregate-per-command terminology with multi-stream event sourcing
  • Made PostgreSQL adapter generic over event type for better type safety
  • Updated Command trait to include StreamResolver for flexible stream discovery
  • Enhanced concurrency control to check all read stream versions
  • Improved CI configuration with PostgreSQL services and coverage optimization

Fixed

  • PostgreSQL schema initialization concurrency issues in CI
  • All pre-commit hook failures across the codebase
  • CI workflow syntax errors and configuration issues
  • Test isolation with unique stream IDs and database cleanup
  • Race conditions in concurrent command execution

Security

  • Forbid unsafe code throughout the workspace
  • Comprehensive security audit integration in CI
  • Protection against dependency vulnerabilities

[0.1.3] - 2025-07-07

Fixed

  • PostgreSQL test configuration (missing TEST_DATABASE_URL) in PR #31
  • Documentation sync script symlink issue in PR #31
  • Cargo.toml version specifications for crates.io publishing in PR #33
  • CSS directory creation for documentation builds in PR #33
  • Workspace dependency syntax errors (rand.workspace = true to rand = { workspace = true })
  • Version conflicts preventing re-release after partial crates.io publishing
  • Circular dependency in eventcore-macros preventing crates.io release
  • Publishing order to resolve dev-dependency circular dependencies

Changed

  • Implemented workspace dependencies for internal crates to enable automatic lockstep versioning
  • Updated publishing order to macros → memory → postgres → eventcore
  • Added PR template compliance rules to CLAUDE.md
  • Improved PR validation workflow with debouncing and comment deduplication
  • Replaced PR validation workflow with Definition of Done bot
  • Removed version numbers from internal workspace dependencies for cleaner dependency management

Added

  • PR template compliance enforcement in development workflow
  • Definition of Done bot configuration for automatic PR checklists
  • Critical rule #4 to CLAUDE.md: Always stop and ask for help rather than taking shortcuts

[0.1.2] - 2025-07-05

Fixed

  • Rand crate v0.9.1 deprecation errors:
    • Updated thread_rng() to rng() across codebase
    • Updated gen() to random() and gen_range() to random_range()
    • Fixed ThreadRng Send issue in stress tests
  • OpenTelemetry v0.30.0 API breaking changes:
    • Updated Resource::new() to Resource::builder() pattern
    • Removed unnecessary runtime parameter from PeriodicReader::builder()
    • Added required grpc-tonic feature to opentelemetry-otlp dependency
  • Bincode v2.0.1 API breaking changes:
    • Updated to use bincode::serde::encode_to_vec() and bincode::serde::decode_from_slice()
    • Added “serde” feature to bincode dependency
    • Replaced deprecated bincode::serialize() and bincode::deserialize() functions

Changed

  • Updated actions/configure-pages from v4 to v5 (PR #3)
  • Updated codecov/codecov-action from v3 to v5 (PR #4)

[0.1.1] - 2025-07-05

Added

  • Modern documentation website with mdBook
    • GitHub Pages deployment workflow
    • Custom EventCore branding and responsive design
    • Automated documentation synchronization from markdown sources
    • Deployment on releases with version information
  • Comprehensive security infrastructure:
    • SECURITY.md with vulnerability reporting via GitHub Security Advisories
    • Improved cargo-audit CI job using rustsec/audit-check action
    • Dependabot configuration for automated dependency updates
    • CONTRIBUTING.md with GPG signing documentation
    • Security guide in user manual covering authentication, encryption, validation, and compliance
    • COMPLIANCE_CHECKLIST.md mapping to OWASP/NIST/SOC2/PCI/GDPR/HIPAA
    • Pull request template with security and performance review checklists
  • GitHub Copilot instructions for automated PR reviews
  • Pre-commit hook improvements:
    • Added doctests to pre-commit hooks
    • Auto-format and stage files instead of failing
  • GitHub MCP server integration for all GitHub operations

Fixed

  • Outdated Command trait references (now CommandLogic) in documentation
  • Broken documentation links in README.md
  • License information to reflect MIT-only licensing
  • Doctest compilation error in resource.rs

Changed

  • Reorganized documentation structure (renumbered operations to 07, reference to 08)
  • Consolidated documentation to single source (symlinked docs/manual to website/src/manual)
  • Updated PR template to remove redundant pre-merge checklist and add Review Focus section
  • Enhanced CLAUDE.md with GitHub MCP integration and PR-based workflow documentation
  • Simplified PR template by consolidating multiple checklists into single Submitter Checklist

[0.1.0] - Initial Release

Added

  • Core Event Sourcing Foundation

    • StreamId, EventId, EventVersion types with validation
    • Command trait system with type-safe execution
    • Event store abstraction with pluggable backends
    • Multi-stream atomicity with optimistic concurrency control
    • Event metadata tracking (causation, correlation, user)

  • Type-Driven Development

    • Extensive use of nutype for domain type validation
    • Smart constructors that make illegal states unrepresentable
    • Result types for all fallible operations
    • Property-based testing with proptest

  • PostgreSQL Adapter (eventcore-postgres)

    • Full PostgreSQL event store implementation
    • Database schema migrations
    • Transaction-based multi-stream writes
    • Optimistic concurrency control with version checking
    • Connection pooling and error mapping

  • In-Memory Adapter (eventcore-memory)

    • Fast in-memory event store for testing
    • Thread-safe storage with Arc
    • Complete EventStore trait implementation
    • Version tracking per stream

  • Command System

    • Type-safe command execution
    • Automatic state reconstruction from events
    • Multi-stream read/write operations
    • Retry mechanisms with exponential backoff
    • Command context and metadata support

  • Projection System

    • Projection trait for building read models
    • Checkpoint management for resume capability
    • Projection manager with lifecycle control
    • Event subscription and processing
    • Error recovery and retry logic

  • Monitoring & Observability

    • Metrics collection (counters, gauges, timers)
    • Health checks for event store and projections
    • Structured logging with tracing integration
    • Performance monitoring and alerts

  • Serialization & Persistence

    • JSON event serialization with schema evolution
    • Type registry for dynamic deserialization
    • Unknown event type handling
    • Migration chain support

  • Developer Experience

    • Comprehensive test utilities and fixtures
    • Property test generators for all domain types
    • Event and command builders
    • Assertion helpers for testing
    • Test harness for end-to-end scenarios

  • Macro System (eventcore-macros)

    • #[derive(Command)] procedural macro
    • Automatic stream field detection
    • Type-safe StreamSet generation
    • Declarative command! macro

  • Examples (eventcore-examples)

    • Banking domain with money transfers
    • E-commerce domain with order management
    • Order fulfillment saga with distributed transaction coordination
    • Complete integration tests
    • Usage patterns and best practices

  • Benchmarks (eventcore-benchmarks)

    • Command execution performance tests
    • Event store read/write benchmarks
    • Projection processing benchmarks
    • Memory allocation profiling

  • Documentation

    • Comprehensive rustdoc for all public APIs
    • Interactive tutorials for common scenarios
    • Usage examples in documentation
    • Migration guides and best practices

Performance

  • Target: 5,000-10,000 single-stream commands/sec
  • Target: 2,000-5,000 multi-stream commands/sec
  • Target: 20,000+ events/sec (batched writes)
  • Target: P95 command latency < 10ms

Breaking Changes

  • N/A (initial release)

Migration Guide

  • N/A (initial release)

Dependencies

  • Rust: Minimum supported version 1.70.0
  • PostgreSQL: Version 15+ (for PostgreSQL adapter)
  • Key Dependencies:
    • tokio 1.45+ for async runtime
    • sqlx 0.8+ for PostgreSQL integration
    • uuid 1.17+ with v7 support for event ordering
    • serde 1.0+ for serialization
    • nutype 0.6+ for type safety
    • miette 7.6+ for enhanced error diagnostics
    • proptest 1.7+ for property-based testing

Architecture Highlights

  • Multi-Stream Event Sourcing: Commands define their own consistency boundaries
  • Type-Driven Development: Leverage Rust’s type system for domain modeling
  • Functional Core, Imperative Shell: Pure business logic with side effects at boundaries
  • Parse, Don’t Validate: Transform unstructured data at system boundaries only
  • Railway-Oriented Programming: Chain operations using Result types

Versioning Strategy

EventCore follows Semantic Versioning with the following guidelines:

Major Version (X.0.0)

  • Breaking changes to public APIs
  • Changes to the Command trait signature
  • Database schema changes requiring migration
  • Changes to serialization format requiring migration

Minor Version (0.X.0)

  • New features and capabilities
  • New optional methods on traits
  • New crates in the workspace
  • Performance improvements
  • New configuration options

Patch Version (0.0.X)

  • Bug fixes
  • Documentation improvements
  • Dependency updates (compatible versions)
  • Internal refactoring without API changes

Workspace Versioning

All crates in the EventCore workspace share the same version number to ensure compatibility:

  • eventcore (core library)
  • eventcore-postgres (PostgreSQL adapter)
  • eventcore-memory (in-memory adapter)
  • eventcore-examples (example implementations)
  • eventcore-benchmarks (performance benchmarks)
  • eventcore-macros (procedural macros)

Pre-release Versions

  • Alpha: X.Y.Z-alpha.N - Early development, APIs may change
  • Beta: X.Y.Z-beta.N - Feature complete, testing phase
  • RC: X.Y.Z-rc.N - Release candidate, final testing

Compatibility Promise

  • Patch versions: Fully compatible, safe to upgrade
  • Minor versions: Backward compatible, safe to upgrade
  • Major versions: May contain breaking changes, migration guide provided

Contributing

When contributing to EventCore:

  1. Follow the conventional commits format
  2. Update this CHANGELOG.md with your changes
  3. Ensure all tests pass and coverage remains high
  4. Update documentation for any API changes
  5. Add property-based tests for new functionality

Commit Message Format

type(scope): description

[optional body]

[optional footer]

Types: feat, fix, docs, style, refactor, test, chore Scopes: core, postgres, memory, examples, macros, benchmarks