Background Jobs

Spiderly apps run background work on Hangfire. By default Hangfire builds a job class the container doesn't know by constructing it on the spot, so a job whose dependency was never registered starts fine and fails the first time it runs. Spiderly's job seam closes that gap: every job becomes a registered service, and Hangfire builds jobs only from the container.

Opt in

Pass the assemblies that hold your jobs:

services.AddSpiderly<MyDbContext>(Configuration, spiderly =>
{
    // ...
    spiderly.AddJobs(typeof(Startup).Assembly, typeof(InvoiceExportJob).Assembly);
});

This does two things in one call:

• registers every class implementing ISpiderlyJob in those assemblies (scoped, one instance per job run);
• replaces Hangfire's job activator with SpiderlyJobActivator, which builds only registered jobs and refuses anything else with an error naming the job.

It works whether services.AddHangfire(...) runs before or after AddSpiderly. Together with a host that validates its service graph at boot (ValidateOnBuild), every job's constructor is checked before the first job runs.

Write a job

using Spiderly.Shared.Jobs;

public class InvoiceExportJob : ISpiderlyJob
{
    private readonly IApplicationDbContext _context;

    public InvoiceExportJob(IApplicationDbContext context) => _context = context;

    public async Task ExportAsync(long invoiceId)
    {
        // ...
    }
}

ISpiderlyJob has no members; it marks the class as a job. You don't register it yourself, the scan does.

Schedule it

Schedule through the typed methods. They accept only a class that implements ISpiderlyJob, so every job you schedule is one the container registered:

// Fire and forget, from an injected IBackgroundJobClient
backgroundJobClient.EnqueueJob<InvoiceExportJob>(job => job.ExportAsync(invoiceId));

// Recurring, from IRecurringJobManager in the Configure phase
IRecurringJobManager jobs = app.ApplicationServices.GetRequiredService<IRecurringJobManager>();
jobs.AddOrUpdateJob<InvoiceExportJob>(
    "invoice-export-nightly",
    job => job.ExportAllAsync(),
    "0 2 * * *",
    new RecurringJobOptions { TimeZone = TimeZoneInfo.Utc });

Hangfire's own Enqueue<T> and AddOrUpdate<T> accept any type. If you want the compiler to refuse a job that isn't marked, ban them in your app (for example with a banned-symbols analyzer) and use EnqueueJob and AddOrUpdateJob everywhere.

Spiderly's own jobs

The jobs Spiderly schedules for you are registered by the features that schedule them, whether or not you call AddJobs:

SpiderlyUseOutboxRecurringJob schedules through the container's IRecurringJobManager, so it needs services.AddHangfire(...), which every app that runs jobs already has.