Event Sourcing

Cephalon.EventSourcing adds an event-sourced storage capability — appending to per-aggregate streams, replaying for projections, snapshot support. Adapter packages back the streams with a specific store.

⚠️

Maturity: the whole family is currently M2. Surface is settling; expect minor breaking schema changes within preview minors. Maturity audit.

Packages

Click any package name to jump to its source-doc.

Base

Package	NuGet ID	Maturity	Capability
EventSourcing (base)	Cephalon.EventSourcing	M2	Capability.EventSourcing

Storage adapters

Package	NuGet ID	Engine:EventSourcing:Provider	Read model fit
EF Core	Cephalon.EventSourcing.EntityFramework	"EntityFramework"	Relational projections
Cassandra	Cephalon.EventSourcing.Cassandra	"Cassandra"	Wide-column projections, very high write rate
ClickHouse	Cephalon.EventSourcing.ClickHouse	"ClickHouse"	OLAP projections, analytics
Elasticsearch	Cephalon.EventSourcing.Elasticsearch	"Elasticsearch"	Full-text projections
MongoDB	Cephalon.EventSourcing.MongoDB	"MongoDB"	Document projections
NATS JetStream	Cephalon.EventSourcing.Nats	"Nats"	Stream-native — JetStream backs every aggregate stream
Neo4j	Cephalon.EventSourcing.Neo4j	"Neo4j"	Graph projections
OpenSearch	Cephalon.EventSourcing.OpenSearch	"OpenSearch"	Apache-licensed search projections
Qdrant	Cephalon.EventSourcing.Qdrant	"Qdrant"	Vector / similarity projections
Redis Streams	Cephalon.EventSourcing.Redis	"Redis"	Low-latency, in-memory streams

Install matrix

Scenario	Packages
Event-sourced aggregate in EF Core	Cephalon.EventSourcing + Cephalon.EventSourcing.EntityFramework
Event-sourced + ClickHouse projection	+ Cephalon.EventSourcing.ClickHouse
Multiple read-model targets	install one adapter per read-model target

Configuration shape

appsettings.json

{
  "Engine": {
    "EventSourcing": {
      "Enabled": true,
      "Provider": "EntityFramework",
      "Snapshots": { "Every": 100 },
      "Projections": {
        "RebuildOnSchemaChange": true
      }
    }
  }
}

See also

• Reference → Components → Eventing — message-passing eventing (different from event-sourced storage).
• Technology → Eventing — CQRS + event-sourcing patterns.