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Use BaseDbContext for EF Core mapping in Arc

Cratis Arc’s BaseDbContext applies JSON, ConceptAs<T> and Guid conversions so you do not repeat them in every EF Core context. Register the context through Arc’s helpers to also apply your IEntityTypeConfiguration<T> entity mappings.

Define and register a context

Section titled “Define and register a context”

Inherit from BaseDbContext, pass the options to its constructor, and expose your application’s Customer entity through a DbSet<Customer>:

using Cratis.Arc.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;


public class StoreDbContext(DbContextOptions<StoreDbContext> options) : BaseDbContext(options)
{
    public DbSet<Customer> Customers => Set<Customer>();
}

Register the context in your existing host’s service collection:

services.AddDbContextWithConnectionString<StoreDbContext>(
    "Data Source=store.db",
    (serviceProvider, options) => options.EnableDetailedErrors());

Import Microsoft.Extensions.DependencyInjection for service registration. The callback is Action<IServiceProvider, DbContextOptionsBuilder>.

Converters and entity maps

Section titled “Converters and entity maps”

During OnModelCreating, the base context applies:

Relevant types include owned entities, types directly exposed through DbSet<T>, and entity types referenced directly or through generic properties on those set types. Types stored exclusively inside JSON are excluded from relational concept/Guid mapping.

For geometry properties, configure AsPoint(), AsLineString(), or AsPolygon() explicitly; the base context does not apply those conversions. Choose the separate [Json] path if you want JSON storage instead. See point conversion to choose a representation.

Arc registration supplies an IEntityTypeRegistrar through EF’s application service provider. BaseDbContext uses it to apply entity maps before the conversions. If maps are missing from the model, check registration first: constructing the context directly or using ordinary EF registration without those services and options does not supply the registrar.

Pooling and customization

Section titled “Pooling and customization”

Arc’s helpers register a pooled IDbContextFactory<T> and a scoped context. Configure options at registration time; do not change them in OnConfiguring on a pooled context. Contexts created directly through a factory must be disposed by their caller.

If you override OnModelCreating, call base.OnModelCreating(modelBuilder) to retain the conventions. Configuration ordering matters: configure explicit overrides after the base call where appropriate.

For tenant-specific databases or identities, configure connection resolution rather than changing pooled options. Arc resolves those values when a connection opens, including on a reused context. See registration and provider limits before choosing a tenant isolation strategy.

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