> For the complete documentation index, see [llms.txt](https://draekien-industries.wpei.me/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://draekien-industries.wpei.me/reference/integrations.md).

# Integrations

Packages that connect Waystone.Monads to a library you already use. None is required, and none changes how Waystone.Monads behaves.

Each of these bridges `Waystone.Monads` to a library from somewhere else. They put their types in that library's namespaces, so you reach them from a `using` you already have. All ship from the same repository as `Waystone.Monads`, on the same version number, and all are purely additive.

Packages that add to `Waystone.Monads` itself are under [Add-ons](/reference/packages.md).

## Pick a package

| If you need to                                | Install                                          | Page                                                                    |
| --------------------------------------------- | ------------------------------------------------ | ----------------------------------------------------------------------- |
| Assert on an `Option` or a `Result` in a test | `Waystone.Monads.Shouldly`                       | [Shouldly](/reference/integrations/shouldly.md)                         |
| Configure the library from a container        | `Waystone.Monads.Extensions.DependencyInjection` | [Dependency injection](/reference/integrations/dependency-injection.md) |
| Do that, on `Microsoft.Extensions.Hosting`    | `Waystone.Monads.Extensions.Hosting`             | [Hosting](/reference/integrations/hosting.md)                           |
| Get a `Result` back from a validator          | `Waystone.Monads.FluentValidation`               | [FluentValidation](/reference/integrations/fluent-validation.md)        |
| Serialize either type with `System.Text.Json` | `Waystone.Monads.SystemTextJson`                 | [System.Text.Json](/reference/integrations/system-text-json.md)         |
| Serialize either type with Json.NET           | `Waystone.Monads.NewtonsoftJson`                 | [Newtonsoft.Json](/reference/integrations/newtonsoft-json.md)           |

## Two of these are a pair

The two JSON packages write the same format on purpose. Pick the serializer your application already uses — a payload one of them writes is a payload the other reads, and a test in the repository asserts that in both directions.

One exception: if you publish with `PublishAot`, use [System.Text.Json](/reference/integrations/system-text-json.md). Json.NET has no NativeAOT story of its own.

## Two more are a pair

[Hosting](/reference/integrations/hosting.md) depends on [Dependency injection](/reference/integrations/dependency-injection.md), so installing Hosting gives you both. On a host, install Hosting. Everywhere else — a console application, a test, a container you built by hand — install the dependency injection package alone.

## None of them changes the library

No package here changes the behaviour of anything in `Waystone.Monads`.

* Two add vocabulary. Remove [Shouldly](/reference/integrations/shouldly.md) or [FluentValidation](/reference/integrations/fluent-validation.md) and the code that used it stops compiling, and nothing else moves.
* Two change only *who writes* your configuration, not what the settings mean. You can write the same settings by hand with `MonadOptions.Configure`.
* Two teach a serializer a format it did not know. Your own code does not change at all.