//[doc-seo]
{
    "Description": "Define ABP Low-Code entities in C# with attributes and refine them with the Fluent API. This page documents the developer-facing code-first surface, including entity/property attributes, validation behavior, attachments, file/image options, enums, and fluent configuration helpers."
}

[DynamicEnum]
public enum ProductStatus
{
    Draft = 0,
    Active = 1,
    Discontinued = 2
}

[DynamicEntity(DefaultDisplayPropertyName = nameof(Name))]
[DynamicEntityUI("Products")]
[DynamicEntityAttachments(
    "application/pdf",
    "image/png",
    "image/jpeg",
    MaxFileCount = 5,
    MaxFileSizeBytes = 5 * 1024 * 1024
)]
public class Product : DynamicEntityBase
{
    [Required]
    [StringLength(128)]
    [DynamicPropertyUnique]
    public string Name { get; set; } = null!;

    [Display(Name = "Unit Price")]
    [DynamicPropertyType(EntityPropertyType.Money)]
    [DynamicPropertyDefaultValue("0")]
    public decimal Price { get; set; }

    public ProductStatus Status { get; set; }

    [DynamicForeignKey("Catalog.Categories.Category", "Name", ForeignAccess.View)]
    public Guid? CategoryId { get; set; }

    [DynamicPropertyFileOptions(
        "application/pdf",
        MaxSizeBytes = 5 * 1024 * 1024
    )]
    public string? SpecSheet { get; set; }

    [DynamicPropertyImageOptions(
        "image/png",
        "image/jpeg",
        MaxWidth = 1024,
        MaxHeight = 1024,
        MaxSizeBytes = 2 * 1024 * 1024,
        ResizeMode = "fit"
    )]
    public string? HeroImage { get; set; }

    [DynamicPropertyNotMapped]
    public string? SearchSummary { get; set; }
}

AbpDynamicEntityConfig.SourceAssemblies.Add(
    new DynamicEntityAssemblyInfo(typeof(MyDomainModule).Assembly)
);

await DynamicModelManager.Instance.InitializeAsync();

AbpDynamicEntityConfig.EntityConfigurations.Configure<Product>(entity =>
{
    entity.WithDisplayName("Catalog Products");
    entity.EnableAttachments(
        10,
        5 * 1024 * 1024,
        20 * 1024 * 1024,
        "application/pdf",
        "image/png",
        "image/jpeg"
    );

    entity.AddOrGetProperty("DiscountedPrice")
        .AsMoney()
        .WithDefaultValue("0");

    entity.AddCrossFieldValidation(
        "DiscountedPrice",
        "Price",
        EntityCrossFieldValidationOperators.LessThanOrEqual,
        "Discounted price cannot exceed unit price."
    );

    entity.GetProperty("HeroImage").AsImage(
        2 * 1024 * 1024,
        1024,
        1024,
        "fit",
        "image/png",
        "image/jpeg"
    );
});

[DynamicEntity(DefaultDisplayPropertyName = nameof(Name))]
public class Product : DynamicEntityBase
{
    public string Name { get; set; } = null!;
}

[DynamicEntity("Catalog.Orders.Order")]
public class OrderLine : DynamicEntityBase
{
    [DynamicForeignKey("Catalog.Products.Product", "Name")]
    public Guid ProductId { get; set; }
}

[DynamicEntity]
[DynamicEntityUI("Products")]
public class Product : DynamicEntityBase
{
}

[DynamicEntity]
[DynamicEntityAttachments(
    "application/pdf",
    "image/png",
    MaxFileCount = 3,
    MaxFileSizeBytes = 5 * 1024 * 1024,
    MaxTotalSizeBytes = 15 * 1024 * 1024
)]
public class Product : DynamicEntityBase
{
}

[DynamicEntity]
[DynamicEntityCommandInterceptor(
    "Create",
    InterceptorType.Pre,
    "if (!context.commandArgs.data['Name']) { globalError = 'Name is required.'; }"
)]
[DynamicEntityCommandInterceptor(
    "Delete",
    InterceptorType.Post,
    "context.log('Deleted: ' + context.commandArgs.entityId);"
)]
public class Product : DynamicEntityBase
{
    public string Name { get; set; } = null!;
}

[DynamicEnum]
public enum ProductStatus
{
    Draft = 0,
    Active = 1,
    Discontinued = 2
}

[DynamicEntity]
public class Product : DynamicEntityBase
{
    public ProductStatus Status { get; set; }
}

{
  "culture": "en",
  "texts": {
    "Enum:ProductStatus.Draft": "Draft",
    "Enum:ProductStatus.Active": "Active",
    "Enum:ProductStatus.Discontinued": "Discontinued"
  }
}

[DynamicPropertyUI(DisplayName = "SKU")]
public string Code { get; set; } = null!;

[Display(Name = "Unit Price")]
public decimal Price { get; set; }

public class Product : DynamicEntityBase
{
    [DynamicPropertyType(EntityPropertyType.Money)]
    [DynamicPropertyDefaultValue("0")]
    public decimal Price { get; set; }

    [DynamicForeignKey(
        "Catalog.Categories.Category",
        "Name",
        ForeignAccess.View
    )]
    public Guid? CategoryId { get; set; }

    [DynamicForeignKey(
        "Catalog.Products.Product",
        "Name",
        ForeignAccess.View,
        DependsOnPropertyName = nameof(CategoryId),
        DependsOnFilterPropertyName = "CategoryId"
    )]
    public Guid? RelatedProductId { get; set; }

    [DynamicPropertyNotMapped]
    public string? SearchSummary { get; set; }

    [DynamicPropertySetByClients(false)]
    public string? GeneratedCode { get; set; }

    [DynamicPropertyServerOnly]
    public string? InternalNotes { get; set; }

    [DynamicPropertyUnique]
    public string Code { get; set; } = null!;

    [DynamicPropertyFileOptions(
        "application/pdf",
        MaxSizeBytes = 5 * 1024 * 1024
    )]
    public string? SpecSheet { get; set; }

    [DynamicPropertyImageOptions(
        "image/png",
        "image/jpeg",
        MaxWidth = 1024,
        MaxHeight = 1024,
        MaxSizeBytes = 2 * 1024 * 1024,
        ResizeMode = "fit"
    )]
    public string? HeroImage { get; set; }
}

public class Product : DynamicEntityBase
{
    [Required]
    [StringLength(128, MinimumLength = 3)]
    public string Name { get; set; } = null!;

    [Range(0, 100000)]
    public decimal Price { get; set; }

    [EmailAddress]
    public string? ContactEmail { get; set; }
}

AbpDynamicEntityConfig.SourceAssemblies.Add(
    new DynamicEntityAssemblyInfo(
        typeof(MyDomainModule).Assembly,
        rootNamespace: "Catalog",
        projectRootPath: sourcePath
    )
);

await DynamicModelManager.Instance.InitializeAsync();

AbpDynamicEntityConfig.DynamicEntityTypes.Add(typeof(Product));
AbpDynamicEntityConfig.DynamicEnumTypes.Add(typeof(ProductStatus));

AbpDynamicEntityConfig.EntityConfigurations.Configure<Product>(entity =>
{
    entity.WithDisplayName("Products");
});

AbpDynamicEntityConfig.EntityConfigurations.Configure(
    "Catalog.Products.Product",
    entity =>
    {
        entity.WithDisplayName("Products");
    }
);

AbpDynamicEntityConfig.EntityConfigurations.Configure(
    "Catalog.Products.Product",
    entity =>
    {
        entity.WithDisplayName("Products");
        entity.DefaultDisplayPropertyName = "Name";
        entity.EnableAttachments(
            5,
            5 * 1024 * 1024,
            20 * 1024 * 1024,
            "application/pdf",
            "image/png"
        );

        entity.AddOrGetProperty("Code")
            .AsRequired()
            .WithDefaultValue("P-");

        entity.GetProperty("Code").DisplayName = "SKU";

        entity.AddOrGetProperty("Price")
            .AsMoney()
            .AsRequired();

        entity.GetProperty("Price").DisplayName = "Unit Price";

        entity.AddOrGetProperty("Status")
            .WithEnumType("Catalog.Products.ProductStatus");

        entity.AddOrGetProperty("CategoryId")
            .WithForeignKey("Catalog.Categories.Category", "Name", ForeignAccess.View);

        entity.AddOrGetProperty("HeroImage")
            .AsImage(
                2 * 1024 * 1024,
                1024,
                1024,
                "fit",
                "image/png",
                "image/jpeg"
            );

        entity.AddOrGetProperty("InternalNotes")
            .AsServerOnly();

        entity.AddOrGetProperty("DiscountedPrice")
            .AsMoney()
            .WithDefaultValue("0");

        entity.AddCrossFieldValidation(
            "DiscountedPrice",
            "Price",
            EntityCrossFieldValidationOperators.LessThanOrEqual,
            "Discounted price cannot exceed unit price."
        );

        entity.Interceptors.Add(new CommandInterceptorDescriptor("Create")
        {
            Type = InterceptorType.Pre,
            Javascript = "if (!context.commandArgs.data['Name']) { globalError = 'Name is required.'; }"
        });
    }
);

public class CatalogDbContext : AbpDbContext<CatalogDbContext>, IDbContextWithDynamicEntities
{
    protected override void OnModelCreating(ModelBuilder builder)
    {
        builder.ConfigureDynamicEntities();

        base.OnModelCreating(builder);

        builder.ConfigureLowCode();
    }
}

Fluent API > JSON descriptors > Code attributes and CLR metadata > Defaults