Kits

Pavex provides a rich set of first-party constructors.
To leverage them, you must register them with your application's Blueprint: after a while, it gets tedious. To make your life easier, Pavex provides kits: collections of commonly used constructors, organized by application type.

ApiKit

ApiKit is a good starting point for most APIs and it's installed by default in projects created with pavex new.

src/base/blueprint.rs

use pavex::blueprint::Blueprint;
use pavex::kit::ApiKit;

pub fn blueprint() -> Blueprint {
    let mut bp = Blueprint::new();
    ApiKit::new().register(&mut bp);
    // [...]
}

It registers constructors for:

• PathParams
• QueryParams
• BufferedBody
• BodySizeLimit
• JsonBody

Customization

Using a kit it's not an all-or-nothing deal: you can cherry-pick the constructors you need and even customize them.

Skip a constructor

If you don't need a particular constructor, you can skip its registration by setting the corresponding kit field to None:

src/skip/blueprint.rs

use pavex::blueprint::Blueprint;
use pavex::kit::ApiKit;

pub fn blueprint() -> Blueprint {
    let mut bp = Blueprint::new();
    let mut kit = ApiKit::new();
    // The constructor for `PathParams` will not be registered.
    kit.path_params = None;
    kit.register(&mut bp);
    // [...]
}

Tweak a constructor

In other cases, you may want to include a constructor, but the default configuration doesn't fit your requirements.
For example, you might want to change the cloning behavior or the associated error handler.

src/tweak/blueprint.rs

use pavex::blueprint::Blueprint;
use pavex::kit::ApiKit;

pub fn blueprint() -> Blueprint {
    let mut bp = Blueprint::new();
    let mut kit = ApiKit::new();
    kit.buffered_body = kit.buffered_body.map(|b| b.clone_if_necessary());
    kit.register(&mut bp);
    // [...]
}

Replace a constructor

You can also replace one of the constructors provided by the kit with a custom one.

src/replace/blueprint.rs

use pavex::blueprint::constructor::Constructor;
use pavex::blueprint::Blueprint;
use pavex::f;
use pavex::kit::ApiKit;

pub fn blueprint() -> Blueprint {
    let mut bp = Blueprint::new();
    let mut kit = ApiKit::new();
    let c = Constructor::request_scoped(f!(crate::custom_path_params)); // (1)!
    kit.path_params = Some(c);
    kit.register(&mut bp);
    // [...]
}

1. When working with a kit, you configure the constructor without registering it directly with the blueprint.
   The kit takes care of the registration for you when its register method is invoked.