Janzen.Pagination — guide

Three pages, in reading order. Each stands on its own, so jumping straight to the one you need also works.

Page	What it answers
Getting started	Install, register, and get a paginated endpoint returning JSON — plus what the engine does with the request once it arrives.
Configuration	What an allow-list buys you, and the three decisions every config has to make.
Projections	The four Paginate*Async entry points and how to pick between them.

The 30-second version

// 1. Declare the contract for an entity — nothing outside it is addressable from the query string.
var config = PaginateConfig<Product>.Create(b => b
    .WithLimits(defaultLimit: 25, maxLimit: 100)
    .Sortable("name", p => p.Name)
    .DefaultSortBy("name")
    .WithTieBreaker(p => p.Id)
    .Searchable("name", p => p.Name)
    .Filterable("status", p => p.Status, PaginateFilterOperator.Eq, PaginateFilterOperator.In));

// 2. Execute it against any IQueryable.
PaginatedResponse<ProductDto> page = await db.Products.PaginateAsync<Product, ProductDto>(request, config);

GET /products?page=2&limit=25&sortBy=name:DESC&search=acme&filter.status=$in:active,pending

The engine works on its own against any IQueryable<T>; the ASP.NET Core, PostgreSQL and NodaTime packages are independent add-ons, so take only the ones you need.

When the guide is not what you want

The guide is prose you follow once. The rest of the site is shaped for other moments:

• Reference is looked up mid-task — the request and response contracts, every builder method and what it refuses, the composers that hand the query back unexecuted, and every 400.
• Integrations is per package: what changes when you add one.
• Cookbook is task-shaped — role-based configs, collection filters, aggregates, non-web callers, testing.