Stratara.Projections
4.4.5
Prefix Reserved
dotnet add package Stratara.Projections --version 4.4.5
NuGet\Install-Package Stratara.Projections -Version 4.4.5
<PackageReference Include="Stratara.Projections" Version="4.4.5" />
<PackageVersion Include="Stratara.Projections" Version="4.4.5" />
<PackageReference Include="Stratara.Projections" />
paket add Stratara.Projections --version 4.4.5
#r "nuget: Stratara.Projections, 4.4.5"
#:package Stratara.Projections@4.4.5
#addin nuget:?package=Stratara.Projections&version=4.4.5
#tool nuget:?package=Stratara.Projections&version=4.4.5
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 |
Abstractions/ |
IProjection and its refinements: IRebuildableProjection (can be rebuilt alone on the Orleans execution model) and IForgetsDeletedTenants (a fact recorded for a tenant after its deletion is passed over instead of failing the projection; the record is kept by IForgottenTenantStore, which the read store provides), and IReadModelPreservation (lets a failed replay restore the read models it emptied; the PostgreSQL implementation comes with AddReadModelRestore<TReadContext>()) |
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 (>= 4.4.5)
- Stratara.Domain (>= 4.4.5)
- Stratara.Shared (>= 4.4.5)
NuGet packages (3)
Showing the top 3 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; maps pgvector types for a model that uses them, and needs no database extension otherwise. |
|
|
Stratara.EventSourcing.WorkerDefaults
Worker-host wiring composites for the Stratara event-sourced stack. IHostApplicationBuilder extensions (AddBackendServices, AddCommandWorkerServices, AddHeavyCommandWorkerServices, AddEventProjectionWorkerServices, AddEventStreamHashWorkerServices, AddSagaWorkerServices, AddOutboxWorkerServices, and AddCommandServices, AddEventProjectionServices and AddSagaServices without the bus-fed workers) bundle the per-concern DI calls so each worker host opts in with one line. |
|
|
Stratara.Orleans
The Orleans execution model for the Stratara event-sourced stack — one activation per aggregate across the cluster, commands recorded before the call returns and resumed after a crash, projections and sagas that read the store in commit order from a checkpoint, singleton work, owner-checked durable timers and heavy work bounded across the cluster. |
GitHub repositories
This package is not used by any popular GitHub repositories.
| Version | Downloads | Last Updated |
|---|---|---|
| 4.4.5 | 62 | 10/14/2026 |
| 4.4.4 | 292 | 10/10/2026 |
| 4.4.3 | 133 | 10/10/2026 |
| 4.4.2 | 364 | 10/2/2026 |
| 4.4.1 | 419 | 9/29/2026 |
| 4.4.0 | 178 | 9/27/2026 |
| 4.3.1 | 182 | 9/25/2026 |
| 4.3.0 | 342 | 9/23/2026 |
| 4.2.0 | 221 | 9/18/2026 |
| 4.1.1 | 141 | 9/16/2026 |
| 4.1.0 | 147 | 9/16/2026 |
| 4.0.4 | 969 | 9/14/2026 |
| 4.0.3 | 200 | 9/3/2026 |
| 4.0.2 | 636 | 9/3/2026 |
| 4.0.1 | 370 | 9/2/2026 |
| 4.0.0 | 186 | 8/31/2026 |
| 4.0.0-preview.1 | 84 | 8/31/2026 |
| 3.4.0 | 176 | 8/28/2026 |
| 3.3.0 | 147 | 8/25/2026 |
| 3.2.3 | 170 | 8/22/2026 |
A command can now say whose data its protected fields are. Until now a command's `[EncryptData]` fields were
encrypted for the session that dispatched it, so a session with no tenant could not protect anything and a session
with another tenant protected under the wrong one. Additive and opt-in; no schema change and no migration. One
ordering rule applies once a host starts using it (see *Changed*).
### Added
- **A command can name the owner of its protected fields.** A command that implements the new `INamesDataOwner`
(`Stratara.Abstractions.Security`: `Guid DataOwnerTenantId`, optional `Guid? DataOwnerUserId`) has its
`[EncryptData]` fields encrypted for that owner wherever the framework serializes it — the copy the outbox, the
bus and the Orleans record carry to its handler, and the copy the command audit records — whatever session
dispatched it. It is to a command what `IAggregateCreationEvent` is to a stream's first event. Three cases it
answers: a session with no tenant (an anonymous endpoint, or a saga reacting to a fact one recorded) could not
encrypt a `TenantScoped` field at all outside development; a session with another tenant than the data's owner
encrypted it under that tenant's key, silently, so the real owner's erasure left the audit record readable; and
the two copies of one command were written for different users. For a command that names its owner, both copies
are written for the same tenant and the same user.
- **The audit record of such a command is attributed to the named owner.** Its data-owner tenant and user are the
owner the command names; its actor is the session's, as before. A tenant's view of the command log then holds the
commands that carried its data, whoever issued them, and each record can be read back from its own columns.
- **`CommandEnvelope.DataOwnerTenantId` and `.DataOwnerUserId`** carry the owner beside the session context. They
are set only for a command that names an owner and are omitted from the JSON otherwise; the constructor and
`Deconstruct` are unchanged. The handling host reads the command's protected fields for the owner the envelope
carries and runs the handler under the session it carries.
- **`CommandDataOwner`** (`Stratara.Shared.Security`) is the one resolution every writer and reader of a command
uses, for a host that serializes commands itself.
### Changed
- **The bus-envelope signature covers a named owner.** A signed command does not verify when it is presented with
another data owner, or with its owner removed. A command that names no owner has the canonical form it had before,
so publishers and consumers on either side of this release verify each other's signatures for it and a fleet in
`Strict` mode upgrades without a pass through `Permissive`.
- **Upgrade the hosts that handle commands before a host dispatches a command that names an owner.** A command
worker or silo on an earlier release cannot read the owner. It does not run the handler with the fields emptied:
in `Strict` mode the signature does not verify, otherwise the read fails authentication, and the message is
retried and then kept. Two deployments are the simple order — this release first, the declarations after.
- **Nothing changes for a command that names no owner.** It is serialized, stored, published and signed as before.
That includes a divergence this release states rather than removes: its travelling copy is written for the
session's tenant and the *acting* user, its audit record for the session's tenant and the session's *data-owner*
user — for an ordinary signed-in request, a user and nobody. Aligning that default would re-key every protected
command field in transit and is left to a major version; a command that names its owner is not affected.
### Security
- **An erasure now reaches a command's protected fields where the command names its owner.** `ISubjectEraser`'s
documentation said the command audit log and the outbox are left alone. Their rows still are; what it now also
says is what happens to protected fields in them. A command that names its owner has them under that owner's key
in both places, so the owner's erasure leaves the record of the command with those fields unreadable, and a
command still waiting reaches its handler with them absent.
- **A command that names an empty tenant, or an empty user, as its owner is refused.** It fails with
`ArgumentException` naming the command type where it is recorded and where it is dispatched, and nothing is
recorded or sent. It does not fall back to the session, which would hide a caller's mistake in valid ciphertext
under the wrong tenant's key.
- **Naming an owner authorizes nothing, and the owner is taken as stated.** Nothing compares the named owner
against the session; the handler runs under the dispatching session, and authorization and tenant isolation decide
as they do for any other command. Nothing checks that the named tenant exists either, and key material is created
for it on first use — name an owner the code resolved from something it trusts, never one copied from a request.
- **A command encrypted as a whole does not outlive its owner.** With `[EncryptData]` on individual fields, a
command still waiting when its owner is erased reaches its handler with those fields absent. With `[EncryptData]`
on the class there is nothing left to rebuild: the command is retried and then kept, and its handler does not run.
That is how a command whose session tenant was erased already behaved; it is now stated.