cargo_feature_collections.md

---

title: Cargo Feature Collections
authors: ["@cart"]
pull_requests: [21472]

---

Historically, Bevy developers have lived one of two lifestyles:

1. Use all of Bevy's default features, potentially compiling many unwanted or unneeded features.

2. Disable Bevy's default features and manually define the complete list of features.

Living in the world of (2) was an exercise in frustration, as the list of bevy features is massive and the features required to accomplish a given task changes regularly across releases. This was an expert level task that required intimate knowledge of engine internals to get right.

Bevy 0.18 introduces high-level "cargo feature collections" to the bevy crate: 2d, 3d, and ui. This enables developers to easily select the kind of app they want to build, and only compile the pieces of Bevy needed for that app.

This means scenarios like using Bevy as a UI framework, without pulling in the rest of the engine, is now as easy as:

bevy = { version = "0.18", default-features = false, features = ["ui"] }

We've also added mid-level feature collections like 2d_api, which is Bevy's 2D API without the default Bevy renderer. This makes it much easier to swap out the default Bevy renderer for a custom one.

For example, the 2d profile looks like this:

2d = [
  "default_app",
  "default_platform",
  "2d_api",
  "2d_bevy_render",
  "ui",
  "scene",
  "audio",
  "picking",
]

Someone building a custom 2D renderer now just needs to remove 2d_bevy_render and provide their own.

Developers can now define their own high-level cargo feature profiles from these mid-level pieces, making it much easier to define the subset of Bevy you want to build into your app.