Stratara.Projections
4.0.3
Prefix Reserved
dotnet add package Stratara.Projections --version 4.0.3
NuGet\Install-Package Stratara.Projections -Version 4.0.3
<PackageReference Include="Stratara.Projections" Version="4.0.3" />
<PackageVersion Include="Stratara.Projections" Version="4.0.3" />
<PackageReference Include="Stratara.Projections" />
paket add Stratara.Projections --version 4.0.3
#r "nuget: Stratara.Projections, 4.0.3"
#:package Stratara.Projections@4.0.3
#addin nuget:?package=Stratara.Projections&version=4.0.3
#tool nuget:?package=Stratara.Projections&version=4.0.3
Stratara.Projections
Derived. The behaviour described here is specified under
openspec/specs/. Those specifications are the source; this page explains and illustrates them.
License: MIT.
Projection runtime for the Stratara event-sourced stack. Discovers IProjection implementations in the consumer's application assemblies, dispatches event bundles to them, and applies the resulting change sets atomically via the read-model repository layer.
What's in the box
| Folder | Contents |
|---|---|
Services/ |
The runtime, all internal: ProjectionManager (event-bundle → matching projection-handlers fan-out), ProjectionHandler (invokes a projection's matching methods), ProjectionMethodInvoker (reflection-cached method-pointer dispatch into consumer projections). You implement IProjection; these drive it |
Multitenancy/ |
TenantProjection — the framework's own opinionated tenant aggregate projection. Skip the registration if your application has its own tenancy model |
Diagnostics/Extensions/ |
Source-generated LoggerProjectionExtensions, LoggerChangeSetExtensions, LoggerUpdateExtensions — typed [LoggerMessage] surfaces under the Stratara.Projection.* / Stratara.ChangeSet.* / Stratara.Update.* event-ID bands |
Quick start
// In your EventProjection worker:
builder.Services
.AddProjectionWorker(builder.Configuration) // the runtime + hosted service
.AddProjectionsFromAssemblyContaining<MyAppProjectionMarker>(); // your IProjection implementations
Then implement IProjection in your application assembly. The projection manager picks them up automatically.
Both calls are needed: AddProjectionsFromAssemblyContaining<T>() only registers your projections —
AddProjectionWorker(IConfiguration) registers the manager, the invoker and the hosted service that
consumes the event-bundle subscription. Without it nothing drives your projections. Most hosts get
both from the AddEventProjectionWorkerServices() composite in Stratara.EventSourcing.WorkerDefaults.
No checkpoint store. Projections are driven push-wise off the event bus; the framework keeps no per-projection checkpoint, so there is no consumer-lag metric and no built-in resume-from-sequence. Replay is coordinated separately (see
Stratara.Outbox.RabbitMQ's replay state).
Dependencies
Stratara.Contracts— forEventBundle+IEvent<T>.Stratara.Domain— for the framework'sTenantaggregate (only consumed byTenantProjection).Stratara.Shared— for change-tracking primitives, reflection cache, partitioning helpers, diagnostics base.Microsoft.Extensions.Hosting.Abstractions+Microsoft.Extensions.Options.ConfigurationExtensions— for projection-worker checkpointing options.JetBrains.Annotations— for static-analysis attributes on projection-handler conventions.
| Product | Versions Compatible and additional computed target framework versions. |
|---|---|
| .NET | net10.0 is compatible. net10.0-android was computed. net10.0-browser was computed. net10.0-ios was computed. net10.0-maccatalyst was computed. net10.0-macos was computed. net10.0-tvos was computed. net10.0-windows was computed. |
-
net10.0
- JetBrains.Annotations (>= 2026.2.0)
- Microsoft.Extensions.Hosting.Abstractions (>= 10.0.11)
- Microsoft.Extensions.Options.ConfigurationExtensions (>= 10.0.11)
- Stratara.Contracts (>= 4.0.3)
- Stratara.Domain (>= 4.0.3)
- Stratara.Shared (>= 4.0.3)
NuGet packages (2)
Showing the top 2 NuGet packages that depend on Stratara.Projections:
| Package | Downloads |
|---|---|
|
Stratara.EventSourcing.EntityFrameworkCore
EF Core persistence for the Stratara event-sourced stack on PostgreSQL — write-store, read-store, ASP.NET Identity store, shared conventions, value generators, and UnitOfWork primitives. Targets Npgsql with pgvector. |
|
|
Stratara.EventSourcing.WorkerDefaults
Worker-host wiring composites for the Stratara event-sourced stack. IHostApplicationBuilder extensions (AddBackendServices, AddCommandWorkerServices, AddHeavyCommandWorkerServices, AddEventProjectionWorkerServices, AddEventStreamHashWorkerServices, AddSagaWorkerServices, AddOutboxWorkerServices) bundle the per-concern DI calls so each worker host opts in with one line. |
GitHub repositories
This package is not used by any popular GitHub repositories.
| Version | Downloads | Last Updated |
|---|---|---|
| 4.0.3 | 37 | 9/3/2026 |
| 4.0.2 | 157 | 9/3/2026 |
| 4.0.1 | 108 | 9/2/2026 |
| 4.0.0 | 157 | 8/31/2026 |
| 4.0.0-preview.1 | 58 | 8/31/2026 |
| 3.4.0 | 151 | 8/28/2026 |
| 3.3.0 | 126 | 8/25/2026 |
| 3.2.3 | 140 | 8/22/2026 |
| 3.2.2 | 143 | 8/14/2026 |
| 3.2.1 | 160 | 8/2/2026 |
| 3.2.0 | 151 | 7/18/2026 |
| 3.1.7 | 338 | 7/1/2026 |
| 3.1.6 | 578 | 6/22/2026 |
| 3.1.5 | 163 | 6/22/2026 |
| 3.1.4 | 177 | 6/15/2026 |
| 3.1.3 | 166 | 6/10/2026 |
| 3.1.2 | 173 | 6/5/2026 |
| 3.1.1 | 239 | 6/1/2026 |
| 3.1.0 | 158 | 5/30/2026 |
| 3.0.23 | 146 | 5/28/2026 |
Three fixes to the same complaint: a host composed exactly as the documentation describes did not
start. Each one was a registration the composites assumed somebody else had made — a tracer, a unit
of work, a Redis connection — and each is now made by the registration that needs it. Nothing that
already worked changes: every fix defers to a registration the host makes itself, in either order,
so the lines a working host added to get past these gaps can simply be deleted. Additive on every
published surface.
### Fixed
- **A host without Redis starts and dispatches.** Every composite that carries a dispatcher
registered the projection-replay state, and its only implementation took a Redis connection that
no composite registers, so a host composed as documented failed at its first dispatch unless it
also ran Redis and called `AddCaching()`. `AddProjectionReplayState()` now chooses at first
resolution: with a registered `IConnectionMultiplexer` the Redis-backed state as before, without
one an in-process state with the same lease semantics — and a warning, once at start-up
(`104_012`), that replay coordination is confined to that process, so a replay requested there
suppresses publication there only. A deployment whose replay must reach several hosts registers
the shared connection, in either order. Redis-backed hosts observe no change.
- **Registering a store context now registers its unit of work.**
`AddNpgsqlWriteDbContextFactory<T>()` registered the context factory, the context and the default
connection resolver but not the `IWriteUnitOfWork` that the event source, the outbox dispatcher and
the command worker take from the container — and nothing else in the published packages did, so a
host composed exactly as documented failed at its first command with a dependency-injection error.
The write registration now try-adds a scoped `IWriteUnitOfWork` over its context, and
`AddNpgsqlReadDbContextFactory<T>()` try-adds `IProjectionsUnitOfWork` and `IReadUnitOfWork`
likewise. A unit of work the host registers itself, before or after, is still the one used; a
hand-written registration can simply be deleted.
- **`AddMediator()` no longer requires the host to register an OpenTelemetry `Tracer`.** The
mediator traces every dispatch and obtained its tracer from the host, but nothing registered one,
so a host that called `AddMediator()` and nothing else failed at the first resolve of `IMediator`.
`AddMediator()` now registers a fallback that emits the dispatch spans from the framework's
`Stratara.Application` activity source — a host that subscribes to framework telemetry sees them,
a host that subscribes to nothing pays for nothing. A `Tracer` the host registers, before or after
`AddMediator()`, is still the one used, so no existing host changes behaviour; the registration
line can simply be deleted. The samples, the README and the package README no longer carry it.