Initial Baseline Data

Polecat can automatically seed data on application startup using the IInitialData interface.

IInitialData Interface

public class SeedUsers : IInitialData
{
    public async Task Populate(IDocumentStore store, CancellationToken ct)
    {
        await using var session = store.LightweightSession();

        session.Store(new User { FirstName = "Admin", LastName = "User" });
        session.Store(new User { FirstName = "Test", LastName = "User" });

        await session.SaveChangesAsync(ct);
    }
}

Register in configuration:

opts.InitialData.Add(new SeedUsers());

Lambda-Based Seeding

For simple cases, use a lambda:

opts.InitialData.Add(async (store, ct) =>
{
    await using var session = store.LightweightSession();
    session.Store(new DefaultSettings { Id = "default", Theme = "dark" });
    await session.SaveChangesAsync(ct);
});

Execution Order

Initial data runs after schema migration on application startup, before the application starts accepting requests. All registered IInitialData implementations are executed in the order they were registered.

TIP

Initial data seeding runs via the PolecatActivator which is triggered by the .NET host's startup pipeline.