JasperFx Options

JasperFxOptions is the central configuration class for JasperFx. It extends SystemPartBase and participates in the describe command output.

Registering Options

public static void ConfigureOptions(IServiceCollection services)
{
    services.AddJasperFx(opts =>
    {
        // Register an environment check inline
        opts.RegisterEnvironmentCheck(
            "Database connectivity",
            async (sp, ct) =>
            {
                // Verify your database is accessible
                await Task.CompletedTask;
            });
    });
}

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Key Properties

Property	Type	Default	Description
ActiveProfile	string	"Development"	The current application profile
RequiredFiles	string[]	[]	Files that must exist at startup
RememberedApplicationAssembly	Assembly?	null	Override the detected application assembly

Profiles

Settings that should differ between development and production live on a Profile. JasperFxOptions exposes a Development and a Production profile, and selects one as the ActiveProfile at startup based on the hosting environment (Development when IHostEnvironment.IsDevelopment(), otherwise Production).

services.AddJasperFx(opts =>
{
    // Fail fast locally so developers see migration problems immediately (this is the default)
    opts.Development.ResourceMigrationFailureMode = ResourceMigrationFailureMode.FailFast;

    // In production, don't let a transient startup migration failure crash the process
    opts.Production.ResourceMigrationFailureMode = ResourceMigrationFailureMode.ContinueOnFailures;
});

ResourceMigrationFailureMode

Controls what happens when a resource (database schema/migration, message broker objects, etc.) fails to set up or migrate during application startup through the resource setup hosted service (AddResourceSetupOnStartup, or ApplyAllDatabaseChangesOnStartup in the Critter Stack tools).

Value	Behavior
FailFast (default)	A startup resource/migration failure throws and aborts application startup.
ContinueOnFailures	Startup resource/migration failures are logged but do not stop the application from starting.

ContinueOnFailures is intended for production multi-replica deployments. During a rolling deploy, several replicas can race for the migration advisory lock; a replica that loses the race would otherwise fail with "Unable to attain a global lock in time order to apply database changes" and crash-loop, even though the winning replica's committed migration has already made the schema current. With ContinueOnFailures that replica logs the failure and starts up against the now-current schema instead of crash-looping.

RequireFile

Tell JasperFx that a file path is required. This adds a file-exists check to environment tests:

opts.RequireFile("appsettings.json");

RegisterEnvironmentCheck

Register an inline environment check:

opts.RegisterEnvironmentCheck(
    "Redis is reachable",
    async (sp, ct) =>
    {
        // throw on failure
    });

Application Assembly Detection

JasperFx automatically detects the main application assembly for scanning. In test scenarios, you can override this:

JasperFxOptions.RememberedApplicationAssembly = typeof(MyApp).Assembly;

This is useful when test runners or IDEs change the entry assembly.

Next Steps

• Critter Stack Defaults -- Opinionated setup
• Environment Checks -- Startup validation