Skip to content
CephalonEngine

Cephalon.EventSourcing.EntityFramework

Maturity: M1 · Ownership: provider-managed · Family: event-sourcing · See audit, matrix.

Cephalon.EventSourcing.EntityFramework is the first provider-backed event-store baseline for Cephalon event-sourcing workloads.

What it owns

Section titled “What it owns”
  • an Entity Framework Core event-store provider registered through AddCephalonEntityFrameworkEventSourcing<TContext>()
  • the EntityFrameworkEventEntry persistence model for append-only event rows
  • model configuration for the CephalonEvents table and its indexes
  • optimistic-version append semantics on top of IEventStore
  • stream replay reads ordered by StreamVersion
  • a truthful event-stream contribution that identifies the active provider as entity-framework

Main surfaces

Section titled “Main surfaces”
  • EntityFrameworkEventEntry.cs
  • EntityFrameworkEventSourcingConfiguration.cs
  • IEntityFrameworkEventContext.cs
  • Hosting/EntityFrameworkEventSourcingServiceCollectionExtensions.cs
  • Registration/EntityFrameworkEventSourcingEngineBuilderExtensions.cs
  • Services/EntityFrameworkEventStore.cs

Provider usage

Section titled “Provider usage”
builder.Services.AddDbContext<OrdersDbContext>(options =>
    options.UseSqlite(connectionString));


builder.Services.AddCephalonEventSourcing(options =>
{
    options.DefaultProvider = "entity-framework";
});


builder.Services.AddCephalonEntityFrameworkEventSourcing<OrdersDbContext>();

OrdersDbContext must implement IEntityFrameworkEventContext:

public sealed class OrdersDbContext(DbContextOptions<OrdersDbContext> options)
    : DbContext(options), IEntityFrameworkEventContext
{
    public DbSet<EntityFrameworkEventEntry> Events => Set<EntityFrameworkEventEntry>();


    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        EntityFrameworkEventSourcingConfiguration.ConfigureCephalonEvents(modelBuilder);
    }
}

Concurrency semantics

Section titled “Concurrency semantics”
  • GetVersionAsync(streamId) returns -1 when the stream does not exist yet
  • AppendAsync(..., expectedVersion: -1) requires a new stream with no persisted events
  • AppendAsync throws EventStreamConcurrencyException when the persisted version does not match expectedVersion
  • appended events must already carry the exact sequential versions being persisted
  • the provider stores the CLR event type as AssemblyQualifiedName and serializes payloads through System.Text.Json

Not shipped in this slice

Section titled “Not shipped in this slice”

This provider intentionally does not claim:

  • snapshot persistence
  • projection rebuild orchestration
  • archival or retention management
  • background replay workers
  • transport/event-bus integration

It is a narrow append/read provider for the baseline IEventStore contract.

Section titled “Related docs”