modulus add-query

Scaffolds a CQRS query and its handler inside a module's Application layer. Queries represent read operations and always return a result. They are dispatched through the Modulus mediator pipeline and should have no side effects.

Synopsis

modulus add-query <query-name> [options]

Arguments

Argument	Description
<query-name>	PascalCase name for the query (e.g., GetProductById, ListOrders).

Options

Option	Description	Default
--module, -m <name>	(Required) Target module where the query will be created.	--
--result-type, -r <type>	(Required) The return type wrapped in Result<T>. Every query must declare what it returns. Accepts built-in aliases, BCL types, fully-qualified names, nullable, arrays, and generic types (e.g. ProductDto, List<ProductDto>, IReadOnlyList<ProductDto>, PagedResult<OrderSummaryDto>).	--
--solution, -s <path>	Path to the .slnx solution file.	Auto-discovered
--dry-run	Print the files that would be created without writing anything.	Disabled

Generated Output

Running modulus add-query GetProductById --module Catalog --result-type ProductDto generates three files -- the query record and handler under src/Catalog.Application/Queries/GetProductById/, plus a starter unit test in tests/Catalog.Tests.Unit/Queries/. The record and handler are named exactly after the query (no Query suffix is appended):

Query record

src/Modules/Catalog/src/Catalog.Application/Queries/GetProductById/GetProductById.cs

using Modulus.Mediator.Abstractions;

namespace EShop.Catalog.Application.Queries.GetProductById;

public sealed record GetProductById : IQuery<ProductDto>;

Handler class

src/Modules/Catalog/src/Catalog.Application/Queries/GetProductById/GetProductByIdHandler.cs

using Modulus.Mediator.Abstractions;

namespace EShop.Catalog.Application.Queries.GetProductById;

public sealed class GetProductByIdHandler : IQueryHandler<GetProductById, ProductDto>
{
    public Task<Result<ProductDto>> Handle(GetProductById query, CancellationToken cancellationToken = default)
    {
        // TODO: Implement query logic
        throw new NotImplementedException();
    }
}

The result type itself (ProductDto here) is not generated -- define it in the Application layer.

No Validator Generated

Unlike commands, queries do not generate a validator class. Queries are read-only operations and typically do not require input validation beyond what the type system provides. If you need validation on a query, you can add a validator manually and it will be picked up by the validation pipeline behavior automatically.

Examples

Create a query returning a single DTO:

modulus add-query GetProductById --module Catalog --result-type ProductDto

Create a query returning a generic collection directly:

modulus add-query ListProducts --module Catalog --result-type "List<ProductDto>"

Create a query returning a paginated result:

modulus add-query SearchOrders --module Orders --result-type "PagedResult<OrderSummaryDto>"

Create a query with an explicit solution path:

modulus add-query GetCustomerProfile --module Identity --result-type CustomerProfileDto --solution ./EShop.slnx

Preview the files that would be created without writing anything:

modulus add-query GetProductById --module Catalog --result-type ProductDto --dry-run

See Also

• modulus add-command -- Scaffold write-side commands
• modulus add-endpoint -- Wire queries to HTTP GET endpoints
• Commands & Queries -- How the mediator dispatches queries
• Streaming Queries -- For queries that return IAsyncEnumerable<T>