Momentum.Abstractions 0.9.0

Momentum.Abstractions

The contracts of Momentum, an event-driven, multi-tenant workflow framework for .NET. This package has no dependencies and is what your domain code references:

• IEvent / IExternalEvent / EventBase — event contracts (internal bus vs external broker)
• [Step] + ApiStepConfig / EventStepConfig<T> / ExternalEventStepConfig<T> / CronStepConfig — step declarations consumed by Momentum.SourceGenerator
• StepResult — step outcomes mapped to HTTP responses by the generated endpoints
• IMomentumBus / IMomentumPublisher — publish internal/external events from steps
• ScheduleAsync extensions / IScheduledMomentumBus — opt-in durable delayed internal delivery; the runtime binds schedules to the tenant business transaction
• MomentumMessageContext.ScheduledMessageId — stable scheduled-message identity during handling, retry, and replay
• Momentum.Infrastructure — store contracts (IInfrastructureStore and its facets), records, filters and status constants for back-office tooling
• Momentum.Metadata / Momentum.Upcasting — step/topology metadata and event contract upcasting

Install

dotnet add package Momentum.Abstractions

Application projects normally use this package together with Momentum.SourceGenerator for compile-time code generation and Momentum.Runtime for hosting.

Define an event and API step

using Momentum;

public sealed record UserCreated(Guid UserId, string Email) : EventBase;

[Step]
public static partial class CreateUserStep
{
    public static ApiStepConfig Config => new()
    {
        Name = "CreateUser",
        Path = "/users",
        Method = HttpVerb.Post,
        Emits = [typeof(UserCreated)]
    };

    public static async Task<StepResult> Execute(
        CreateUserRequest request,
        IMomentumBus bus,
        Guid tenantId)
    {
        var userId = Guid.NewGuid();
        await bus.PublishAsync(new UserCreated(userId, request.Email)
        {
            TenantId = tenantId
        });

        return StepResult.Created($"/users/{userId}", new { userId });
    }
}

Step classes must be static partial, carry [Step], and expose a supported Config property plus a public static Execute method. The source generator reports invalid definitions with MOM0xx build diagnostics.

License

Momentum is free for qualifying non-commercial open-source projects. Commercial use requires a separate written license agreement. The complete terms are included in the package.