register-referentie/services/domain/Big.Api/Program.cs

using Big.Application;
using Big.Domain;
using Big.Infrastructure;

var builder = WebApplication.CreateBuilder(args);

// Options bound from configuration (compose sets Flowable__* and Acl__* env vars).
builder.Services.AddSingleton(sp => sp.GetRequiredService<IConfiguration>()
    .GetSection("Flowable").Get<FlowableOptions>()
    ?? throw new InvalidOperationException("Missing configuration section 'Flowable'"));
builder.Services.AddSingleton(sp => sp.GetRequiredService<IConfiguration>()
    .GetSection("Acl").Get<AclOptions>()
    ?? throw new InvalidOperationException("Missing configuration section 'Acl'"));

// The in-memory registration store is shared between the submit endpoint and the worker (ADR-0009).
builder.Services.AddSingleton<IRegistrationStore, InMemoryRegistrationStore>();

// The Workflow Client is one type behind two ports (start side + worker side); both resolve to the
// same HttpClient-backed implementation — the only code that talks to Flowable (§8.2).
builder.Services.AddHttpClient<FlowableWorkflowClient>();
builder.Services.AddTransient<IWorkflowClient>(sp => sp.GetRequiredService<FlowableWorkflowClient>());
builder.Services.AddTransient<IExternalWorkerClient>(sp => sp.GetRequiredService<FlowableWorkflowClient>());
builder.Services.AddHttpClient<IAclClient, AclHttpClient>();

builder.Services.AddScoped<SubmitRegistration>();
builder.Services.AddScoped<ApproveRegistration>();
builder.Services.AddScoped<OpenZaakWorker>();
builder.Services.AddScoped<OpenZaakJobProcessor>();

// The hosted external-task job worker polls Flowable and drives OpenZaakAanmaken to completion.
builder.Services.AddHostedService<OpenZaakJobPump>();

var app = builder.Build();

app.MapGet("/health", () => "Healthy");

// Submit a registration. The aggregate is created (INGEDIEND) and the registratie process started;
// the zaak is opened later, off the request path, by the worker — so this returns 202 Accepted with
// a location to read the registration's progress (ADR-0009, eventual consistency).
app.MapPost("/registrations", async (SubmitRegistrationRequest body, SubmitRegistration submit, CancellationToken ct) =>
{
    var id = await submit.HandleAsync(new SubmitRegistrationCommand(body.Bsn), ct);
    return Results.Accepted($"/registrations/{id}", new RegistrationResponse(id.ToString(), RegistrationStatus.Ingediend.ToString(), null));
});

// Temporary admin endpoint (S-09b): approve a registration — the behandelaar's decision, until the
// behandel-portal exists (S-12). The zaak's final status is set via the ACL, which flows back over
// NRC to the projection, making the entry publicly visible as INGESCHREVEN. Idempotent.
app.MapPost("/registrations/{id}/approve", async (string id, ApproveRegistration approve, CancellationToken ct) =>
{
    if (!Guid.TryParse(id, out var guid))
        return Results.NotFound();

    await approve.HandleAsync(new ApproveRegistrationCommand(new RegistrationId(guid)), ct);
    return Results.NoContent();
});

// Read a registration. Its zaak URL appears once the worker has opened the zaak (eventually).
app.MapGet("/registrations/{id}", async (string id, IRegistrationStore store, CancellationToken ct) =>
{
    if (!Guid.TryParse(id, out var guid))
        return Results.NotFound();

    var registration = await store.GetAsync(new RegistrationId(guid), ct);
    return registration is null
        ? Results.NotFound()
        : Results.Ok(new RegistrationResponse(
            registration.Id.ToString(), registration.Status.ToString(), registration.ZaakUrl?.ToString()));
});

await app.RunAsync();

public sealed record SubmitRegistrationRequest(string Bsn);

public sealed record RegistrationResponse(string RegistrationId, string Status, string? ZaakUrl);

public partial class Program;