Sekiban - Event Sourcing and CQRS Framework
Sekiban.Pure support policy / サポート方針
Sekiban.Pure is in maintenance mode (no new features; .NET 9). We plan to complete its lifecycle with .NET 9 (EOL Nov 10, 2026) — but if you run it in production, we will bring it to .NET 10/11 as a pure compatibility migration, no features (we shipped exactly this for Sekiban(Core) 0.25.0: unchanged public API, bidirectional data compatibility). Tell us in #1169. For new projects we recommend Sekiban DCB.
Sekiban.Pure は現在メンテナンスモードです（機能追加なし・.NET 9 対応）。.NET 9 の EOL（2026-11-10）でライフサイクルを完了する予定ですが、本番利用中の方がいれば .NET 10/11 への対応を機能追加なしの互換移行として行います（Sekiban(Core) 0.25.0 で同方式を実施済み: 公開 API 無変更・保存データ双方向互換）。必要な方は #1169 でお知らせください。新規プロジェクトには Sekiban DCB を推奨します。
Sekiban is an event sourcing and CQRS framework for .NET. It supports Azure Cosmos DB, PostgreSQL, and DynamoDB as event stores, with Microsoft Orleans for actor-based scalability.
📚 Documentation: sekiban.dev
Implementations
Note: Sekiban has two implementations. DCB (Dynamic Consistency Boundary) is the recommended approach for new projects. Sekiban.Pure and Sekiban.Core are in maintenance mode.
| Implementation | Description | Status |
|---|
| Sekiban DCB | Dynamic Consistency Boundary - tag-based event sourcing | ✅ Recommended |
| Sekiban.Pure | Traditional aggregate-based event sourcing | 🛠️ Maintenance |
| Sekiban.Core | Single-server version without actor model | 🛠️ Maintenance |
| Sekiban.ts | TypeScript event sourcing | 🔬 Alpha |
Quick Start
Sekiban DCB (Recommended)
dotnet new install Sekiban.Dcb.Templates
dotnet new sekiban-dcb-orleans -n YourProjectName
Cloud Deployment
DCB supports both Azure and AWS:
| Component | Azure | AWS |
|---|
| Event Store | Cosmos DB / PostgreSQL | DynamoDB |
| Snapshots | Azure Blob Storage | Amazon S3 |
| Orleans Clustering | Azure Table / Cosmos DB | RDS PostgreSQL |
| Orleans Streams | Azure Queue | Amazon SQS |
What is DCB?
Dynamic Consistency Boundary (DCB) replaces rigid per-aggregate transactional boundaries with a context-sensitive consistency boundary based on event tags. Instead of maintaining multiple streams and coordinating cross-aggregate invariants via sagas, DCB uses a single event stream per bounded context where each event carries tags representing affected entities.
Key benefits:
- Flexible boundaries: Define consistency scope per command, not per aggregate
- No saga complexity: Cross-entity invariants without compensating events
- Optimistic concurrency: Tag-based conflict detection
- Scalable: Actor model integration with Microsoft Orleans
Learn more at dcb.events
Documentation
- Website: sekiban.dev
- DCB Documentation: docs/dcb_llm (English) | docs/dcb_llm_ja (日本語)
- Pure Documentation: docs/llm (English) | docs/llm_ja (日本語)
- Storage consistency contract (DCB) — what each event store guarantees, and what it does not: English | 日本語. Read this before choosing Cosmos DB for a workload that needs atomic event/tag visibility.
MCP (Model Context Protocol)
Sekiban provides MCP support for AI coding assistants:
claude mcp add sekibanDocument --transport sse https://sekiban-doc-mcp.azurewebsites.net/sse
NuGet Packages
DCB Packages (Recommended)
Legacy Packages
Legacy Sekiban.Core and Sekiban.Pure packages are available on NuGet but are no longer recommended for new projects. See core_main branch for legacy documentation.
Sponsors
Sekiban is Apache 2.0 open source. Support us via GitHub Sponsors.
About
J-Tech Japan (株式会社ジェイテックジャパン) has been developing Sekiban since 2022.
Community
Join the J-Tech JAPAN OSS Discord to ask questions, share ideas, and connect with other Sekiban users. There is a dedicated channel for the Sekiban community.
👉 Join our Discord
Support
For training or support, contact [email protected].
Contributors
License
Apache 2.0 - See License
Copyright (c) 2022- J-Tech Japan
