Stratara.Projections 3.3.0

There is a newer version of this package available.
See the version list below for details.
dotnet add package Stratara.Projections --version 3.3.0
                    
NuGet\Install-Package Stratara.Projections -Version 3.3.0
                    
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="Stratara.Projections" Version="3.3.0" />
                    
For projects that support PackageReference, copy this XML node into the project file to reference the package.
<PackageVersion Include="Stratara.Projections" Version="3.3.0" />
                    
Directory.Packages.props
<PackageReference Include="Stratara.Projections" />
                    
Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.
paket add Stratara.Projections --version 3.3.0
                    
#r "nuget: Stratara.Projections, 3.3.0"
                    
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
#:package Stratara.Projections@3.3.0
                    
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.
#addin nuget:?package=Stratara.Projections&version=3.3.0
                    
Install as a Cake Addin
#tool nuget:?package=Stratara.Projections&version=3.3.0
                    
Install as a Cake Tool

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 — for EventBundle + IEvent<T>.
  • Stratara.Domain — for the framework's Tenant aggregate (only consumed by TenantProjection).
  • 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 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. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

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
4.0.0-preview.1 0 8/31/2026
3.4.0 81 8/28/2026
3.3.0 108 8/25/2026
3.2.3 136 8/22/2026
3.2.2 138 8/14/2026
3.2.1 157 8/2/2026
3.2.0 148 7/18/2026
3.1.7 280 7/1/2026
3.1.6 574 6/22/2026
3.1.5 158 6/22/2026
3.1.4 175 6/15/2026
3.1.3 164 6/10/2026
3.1.2 169 6/5/2026
3.1.1 235 6/1/2026
3.1.0 156 5/30/2026
3.0.23 144 5/28/2026

Two capabilities the framework advertised but did not provide, and a set of guards for behaviour
that failed by succeeding. Crypto-shredding was the headline feature with no way to perform an
erasure; a web host had one mapper for the four failure types it has to answer for. Alongside those,
three things that reported success while doing nothing now report the truth instead — which is why
this release carries breaking entries despite adding no signature you have to change.

### Added

- **`ISubjectEraser` — an erasure is now one call.** Crypto-shredding was the framework's headline
 capability with no way to perform an erasure: four separate sweeps existed, nothing composed them,
 and a consumer had to know all four and get the order right themselves. `AddStrataraErasure()`
 registers a composed operation that sweeps API keys, scoped settings, directory memberships and
 key material — in that order, because a credential that still works can act mid-erasure and
 shredding the key first makes every other plane unreadable. It reports what each plane covered,
 and stops at the first failing plane rather than continuing, so a failed settings sweep is never
 followed by the key shred. What it deliberately does **not** cover is documented: read models your
 own projections built, unprotected event-stream data, the command audit log and outbox, and
 system-wide key material.
- **`AddStrataraProblemDetails()` — one error shape for every framework rejection.** The framework
 raises three failure types a web host has to answer for and shipped a mapper for one of them, so
 both consumers wrote the missing half themselves. The new handler maps a validation rejection to
 `400` with the failures grouped by the field each concerns, and an authorization refusal or
 tenant-access denial to `403`, all as RFC 7807 problem responses. It is opt-in and converts nothing
 else: any failure the framework did not raise propagates untouched, so a host keeping its own error
 model simply does not register it.
- **`ITransaction.SaveChangesIdempotentAsync` — the idempotent-projection write the framework was
 writing by hand.** A projection sees the same event twice under at-least-once delivery, and a row
 can vanish between the read and the write; neither is a fault. The helper commits, and on a
 concurrency conflict asks whether the write's target still exists: gone means a concurrent bundle
 reached the same end state and the commit is satisfied, still there means a real conflict and the
 exception is rethrown so the bundle fails as it must. `TenantProjection` now uses it — and gains
 the distinction, having previously swallowed every conflict.
- **Three guides that did not exist**: evolving an event schema, using the resilience policies, and
 writing an update handler. Each leads with the constraint that costs most to discover late — an
 upcaster sees ciphertext and snapshots are never upcasted; a retry re-runs your handler; a property
 missing on either side of an update is ignored in silence.

### Changed

- **BREAKING — the development key store no longer pretends to erase.** `DummyKeyStore.RevokeAsync`
 and `EraseScopeAsync` completed successfully and shredded nothing, so a consumer exercising an
 erasure path in development got a green result and no shredding. Both now throw
 `NotSupportedException`. The store derives a single key from a fixed pass-phrase and holds no key
 material it could destroy; reporting success was the defect. Register a real `IKeyStore` — the
 file-backed envelope store, an HSM, Key Vault, KMS — to exercise crypto-shredding.
- **BREAKING — a host refuses to start when an aggregate cannot be restored from its snapshot.** An
 aggregate property that holds state and cannot be set from outside the type is not restored by a
 snapshot: the aggregate rebuilds, the events after the snapshot apply, and only what the snapshot
 held for that property is gone — silently, and worse the better snapshotting works.
 `AddEventSourcing()` now scans the registered aggregates at start-up and fails, naming the
 aggregate and the property. Give it a public setter; aggregates use `public set` rather than
 `private set` precisely because snapshot deserialization needs it. Computed properties are
 unaffected — they hold no state and are recomputed after a restore.
- **BREAKING — test-support packages are now kept out of projects that are not test projects.** Both
 `Stratara.Testing` and `Stratara.Testing.EntityFrameworkCore` ship an MSBuild check that fails the
 build with `STRATARA1001` when a referencing project is neither a test project nor opted out. Set
 `StrataraAllowTestSupportOutsideTests=true` for a deliberate exception such as a sample or a
 benchmark. The check travels with the package, so it fires on a `PackageReference` and not on a
 project reference inside a single solution.
- **`AddStrataraTestingEventStore` refuses to register into a running host.** It wires an in-memory
 SQLite database and in-memory doubles, which would start successfully in production and lose every
 write. It now throws `InvalidOperationException` when a registered `IHostEnvironment`, or
 `DOTNET_ENVIRONMENT` / `ASPNETCORE_ENVIRONMENT`, names anything other than `Development`. Where no
 environment is stated at all — the ordinary unit test, which has no host — the call is allowed, so
 existing test suites are unaffected.
- **`command.duration` is documented as what it measures.** It was described as end-to-end command
 latency and is recorded only in the outbox worker, so a host dispatching in-process saw an empty
 histogram and a host doing both saw half its traffic. The instrument and its tags are unchanged —
 only the description.
- **Settings resolve in one read per scope instead of one per setting and scope.** Twenty inherited
 settings over a four-scope fallback chain were up to eighty store round trips; each scope is now
 loaded once. Same fallback order and same results.
- **Snapshot evaluation no longer opens an extra transaction per stream** on the write hot path.

### Deprecated

- **`UseAuthorizationExceptionTo403()`, removed in the next major version.** It maps two refusals to
 a bare status code with no body; `AddStrataraProblemDetails()` supersedes it with a full problem
 response that also covers validation. It keeps working for now — the compiler warning is the
 migration notice. Do not register both: the middleware answers first and the handler never sees the
 exception.