> For the complete documentation index, see [llms.txt](https://brightercommand.gitbook.io/paramore-brighter-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker.md). # Darker - [Darker Basic Configuration](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/darkerbasicconfiguration.md): Darker is the query-side counterpart to Brighter, implementing the Query Object pattern for CQRS (Command Query Responsibility Segregation) architectures. - [Darker Configuration Reference](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/darkerbasicconfiguration/darkerconfigurationreference.md): The options AddDarker and AddHandlersFromAssemblies take: the query processor's service lifetime, and the strategies available for registering handlers. - [Queries and Query Objects](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/queriesandqueryobjects.md): The Query Object pattern separates the parameters of a query from the execution of that query. - [Query Result Types](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/queriesandqueryobjects/queryresulttypes.md): The result type specified in IQuery\ can be any C# type. - [Query Object Validation](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/queriesandqueryobjects/queryobjectvalidation.md): Query objects should validate their parameters to ensure they receive valid data. - [How to Implement a Query Handler](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/implementaqueryhandler.md): Query handlers are the entry point to your query execution logic in Darker. - [Query Handler Dependencies](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/implementaqueryhandler/queryhandlerdependencies.md): Query handlers typically need dependencies like repositories, database contexts, or services to execute queries. - [Testing Query Handlers](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/implementaqueryhandler/testingqueryhandlers.md): Query handlers are easy to test because they have clear inputs (queries) and outputs (results), with dependencies that can be mocked or replaced. - [Query Pipeline and Decorators](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypipeline.md): The Query Pipeline in Darker provides a powerful way to add cross-cutting concerns to your query handlers without modifying the handler code itself. - [Query Pipeline Policies](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypipeline/querypipelinepolicies.md): Darker's policy decorators are powered by Polly, a .NET resilience and transient-fault-handling library. - [Darker and Brighter Pipelines](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypipeline/darkerandbrighterpipelines.md): Darker's query pipeline shares many similarities with Brighter's request pipeline, as both implement the same Russian Doll Model for middleware composition. - [Query Patterns](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypatterns.md): This guide presents common query patterns you'll encounter when building real-world applications with Darker. - [Parameterized Query Patterns](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypatterns/parameterizedquerypatterns.md): Query recipes that take parameters: looking up a single entity, filtering a list, and searching on several criteria at once. - [Pagination Query Patterns](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypatterns/paginationquerypatterns.md): How to page through a large result set in Darker, by offset and by cursor, with the trade-offs of each. - [Projection Query Patterns](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypatterns/projectionquerypatterns.md): How to return only the fields a caller needs: simple projections, projections across joins, and calculated fields. - [Collection and Aggregation Query Patterns](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypatterns/aggregationquerypatterns.md): How to return whole collections, counts, and summary statistics from a query handler. - [Entity Framework Core Query Integration](https://brightercommand.gitbook.io/paramore-brighter-documentation/darker/querypatterns/efcorequeryintegration.md): How to run Darker queries against Entity Framework Core: tracking, eager loading, handler lifetime and compiled queries. --- # Agent Instructions This documentation is published with GitBook. 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