Sample 5 — ASP.NET Core API

Concept: HTTP minimal-API endpoints wired straight to the mediator. Parallel to Sample 1 — pick this one if you want an HTTP front instead of a console.

• Code: samples/Stratara.Sample.AspNetCoreApi
• Lines: ~250
• Read time: 10–15 min
• Prerequisite: any of Samples 1–4. This one is parallel — readable at any point.

What you'll see

1. WebApplication.CreateBuilder(args) + app.MapAccountEndpoints() — a vanilla minimal-API.
2. Each endpoint delegates to IMediator.HandleAsync(...) — no business logic in the endpoint.
3. HTTP status codes mapped from the handler's outcome: 201 Created from OpenAccountCommand, 204 NoContent from DepositCommand, 409 Conflict from InsufficientBalanceException.
4. The RFC 7807 ProblemDetails-style error response uses ASP.NET's built-in Results.Problem(…).

Endpoints

Verb	Route	Handler
POST	/accounts	OpenAccountCommand
POST	/accounts/{id}/deposits	DepositCommand
POST	/accounts/{id}/withdrawals	WithdrawCommand (returns 409 on InsufficientBalanceException)
GET	/accounts/{id}/balance	GetBalanceQuery

Running

dotnet run --project samples/Stratara.Sample.AspNetCoreApi
# Now listening on: http://localhost:5000

Try it:

ID=$(curl -sS -X POST http://localhost:5000/accounts \
  -H 'Content-Type: application/json' \
  -d '{"ownerName":"Alice","initialBalance":100}' \
  | jq -r .id)

curl -sS -X POST http://localhost:5000/accounts/$ID/deposits \
  -H 'Content-Type: application/json' \
  -d '{"amount":50}'

curl -sS http://localhost:5000/accounts/$ID/balance
# {"accountId":"…","balance":150}

Why this layout

• Endpoint = mediator dispatch + HTTP-status translation. Nothing more. The endpoint never opens a DbContext, never speaks to the bus, never knows that OpenAccountCommand returns a Guid.
• The mediator pipeline owns auth, validation, audit, retry. The endpoint is just the HTTP-shape adapter.
• This makes the same handler reusable from a console host, a worker, a gRPC service, or a CLI — without changing the handler.

What's missing

• No outbox — for this sample, all commands run in-process. A production HTTP host would typically use the synchronous mediator for queries + creation flows (where the caller needs the result immediately) and ICommandOutboxDispatcher for fire-and-forget mutations (where async + at-least-once delivery is the right contract).
• No identity / authorization — see Auth Decorators guide to add [RequireRole].