Bevy 0.20 — Cargo features

When to use this skill

• Authoring or auditing a Bevy project's Cargo.toml.
• Trimming the WASM bundle (the single biggest lever).
• Building a headless server (no rendering, no windowing, no audio).
• Writing a custom renderer that needs Bevy's data types but not its render pipeline.
• Migrating a 0.18 or 0.19 manifest: ui, audio, bevy_window and custom_cursor moved collections.

Canonical patterns

Top-level collections (what default is made of)

# default = ["2d", "3d", "ui", "audio"]
[dependencies]
bevy = { version = "0.20", default-features = false, features = ["3d", "ui", "audio"] }
# 3D, no bevy_ui (bring your own UI):
bevy = { version = "0.20", default-features = false, features = ["3d", "audio"] }
# 2D, no bevy_audio (e.g. bevy_seedling):
bevy = { version = "0.20", default-features = false, features = ["2d", "ui"] }

2d, 3d and ui each imply default_app + default_platform + their *_bevy_render stack + scene + picking. Since 0.19 they imply neither ui nor audio; list those explicitly.

Mid-level: API without the default renderer

bevy = { version = "0.20", default-features = false, features = ["3d_api", "bevy_winit", "x11"] }

Table derived from bevy-0.20.1/Cargo.toml.

Headless server

bevy = { version = "0.20", default-features = false, features = [
    "default_app",   # ECS + assets + state + log, no window
    "multi_threaded",
    "serialize",
    "scene",         # only if you spawn glTF / serialize worlds
] }

use bevy::prelude::*;

fn main() {
    // Headless: pair `default-features = false` + "default_app" with
    // `MinimalPlugins`, not `DefaultPlugins` (which needs the render features).
    App::new()
        .add_plugins(MinimalPlugins)
        .add_systems(Update, tick)
        .run();
}

fn tick(time: Res<Time>) {
    let _ = time.delta_secs();
}

Minimal client, opt-in input

bevy = { version = "0.20", default-features = false, features = [
    "3d_bevy_render", "bevy_winit", "x11",   # or "wayland"; "webgl2"/"webgpu" on web
    "mouse", "keyboard", "gamepad",          # input is opt-in without default_platform
    # "touch", "gestures", "bevy_gilrs" (= gamepad + gilrs backend)
] }

Dev-only extras

[features]
dev = ["bevy/dev"]   # = debug + bevy_dev_tools + render_dev_tools + file_watcher

render_dev_tools compiles RenderDebugOverlayPlugin into DefaultPlugins (disabled until you insert RenderDebugOverlayKeybindings { enable_keybindings: true, .. }). Without the feature the overlay is absent; stock DefaultPlugins do not include it.

Feature moves since 0.18

Gotchas

• default-features = false + 3d drops UI and audio. Stale 0.18 manifests then hit "no Node/AudioPlayer". Add ui and/or audio.
• default_app has no window types. Window, WindowPlugin need bevy_window (common_api or explicit).
• bevy_picking without ui_picking gives no UI focus-on-click. Add ui or ui_picking.
• bevy_math/curve no longer exists. cargo fails with "feature curve not found"; use bevy/bevy_curve.
• shader_format_wesl/shader_format_glsl fail to resolve in 0.20. Delete them; port GLSL to WESL.
• Web texture compression: use compressed_image_saver_universal; the new compressed_image_saver output is BCn (desktop) or ASTC (BEVY_COMPRESSED_IMAGE_SAVER_ASTC=4x4), not one-file-everywhere.
• multi_threaded implies std. no_std targets use default_no_std.
• trace_tracy / trace_chrome are separate log sinks; enable one.
• Asset sources: file_watcher (hot reload), embedded_watcher, http/https (ureq), web_asset_cache, asset_processor are all opt-in.

See also

• bevy-wasm-webgpu — the trimmed WASM manifest and webgl2/webgpu.
• bevy-assets — file_watcher, scene, compressed_image_saver* at runtime.
• bevy-migration-0-18-to-0-19 and bevy-migration-0-19-to-0-20 — the upstream feature-move notes.