Bevy project templates

When to use

Load this when choosing a starting Cargo feature set. App construction details stay on bevy-project-foundations. This file does not ship a template repository.

ECS shape

• Profiles: default enables 2d, 3d, ui, and audio. Turn default features off and pick one profile when the binary should stay smaller.
• Windowed games: DefaultPlugins brings the window, input, and the renderer for the features you enabled.
• Headless: MinimalPlugins schedules the app with no window and no renderer. Pair it with default-features = false.

Examples

A 2D crate disables the default set and enables the 2d profile only. Swap the feature for 3d or ui when that is the whole binary.

[package]
name = "game"
version = "0.1.0"
edition = "2021"

[dependencies]
bevy = { version = "0.20", default-features = false, features = ["2d"] }

The 2D starter spawns a camera. The 3D starter does the same with a 3D camera. Both assume DefaultPlugins.

fn setup_2d(mut commands: Commands) {
    commands.spawn(Camera2d);
}

pub struct FlatPlugin;

impl Plugin for FlatPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(Startup, setup_2d);
    }
}

fn main() {
    App::new().add_plugins((DefaultPlugins, FlatPlugin)).run();
}

fn setup_3d(mut commands: Commands) {
    commands.spawn((Camera3d::default(), Transform::from_xyz(0.0, 2.0, 6.0)));
}

pub struct ScenePlugin;

impl Plugin for ScenePlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(Startup, setup_3d);
    }
}

A headless tool uses MinimalPlugins and a plain update system.

fn tick(mut frames: ResMut<FrameCount>) {
    frames.0 += 1;
}

#[derive(Resource, Default)]
struct FrameCount(u32);

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        .init_resource::<FrameCount>()
        .add_systems(Update, tick)
        .run();
}

Same job, Bevy types

Design	Bevy idiom
2D starter	Cargo feature 2d, DefaultPlugins, Camera2d
3D starter	Cargo feature 3d, DefaultPlugins, Camera3d
UI tool	Cargo feature ui plus DefaultPlugins
Headless	default-features = false and MinimalPlugins

Scope

Gitignore and CI files belong to the repository, not to the engine. The feature flag and the plugin set above are the starting point.

Expert Knowledge Delta

Target: Bevy 0.20+.

Core ECS types: Component, Resource, Query, Commands, Startup, Update, Fixed / FixedMain (bevy::time), .chain(), Plugin, DefaultPlugins, MinimalPlugins. Messages and observers are an ownership slot. See bevy-events-messaging for their APIs. Systems run in parallel unless .chain() orders the ones that conflict.

Who owns state

Piece	Owner	Who may mutate	Schedule
Data on one entity	Component	One system via Query	Update or FixedMain
One value for the whole app	Resource	One system	Startup to insert, then the schedule that reads it
Spawn	Commands	The spawning system	Startup for the initial world; later schedules for runtime spawn
Order that must not race	.chain()	The chained systems only	Same schedule
Plugin boundary	Plugin	build registers systems and resources	Before the app runs

Borrow rule: two systems that both mutably query the same component must be ordered (.chain()) or split so only one writes. Unrelated systems stay parallel. That is the ECS page rule, not a guess at a system-set API.

Decision

If you need	Do this	Do not
Per-entity data	Component + Query	A scene-tree script hung on the entity
App-wide config or clock	Resource	Copy the value onto every entity
Stable simulation step	FixedMain and the Fixed clock	Tie simulation to raw frame Update
Startup spawn	Commands in Startup	Spawn from a render system
Cross-system notice that is not shared state	Message or observer slot in bevy-events-messaging	A new event type invented in this file
An API outside the documented set	Check the official docs first	A made-up crate or API

Load references/ecs-ownership.md for the ownership table.

NEVER

• Do not pin /0.20.0/ in docs URLs. WHY: links stay on latest; the 0.20 target is stated once in prose.

• Do not mutably query the same component from two unordered systems. WHY: the schedule runs systems in parallel unless .chain() orders them.

• Do not invent a physics, navigation, networking, or XR crate here. WHY: this skill only names documented Bevy crates and modules.

• No Godot project.godot template or export presets. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No Godot types in Bevy code. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No invented APIs or unnamed third-party crates as the chosen solver. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

Reference

Official pages stay on unversioned bevy.org URLs. The library pin on bevy-master stays 0.20.0.

Official Documentation

• Assets - Official asset catalog. No third-party crate was selected.
• Examples - Example tree on the latest branch.
• ECS - Component, systems, Query, Startup, Update, and .chain().
• Plugins - Plugin, DefaultPlugins, MinimalPlugins, and add_plugins.

Related Skills

Prerequisites

• bevy-master - Hub.
• bevy-project-foundations - Cargo app shell.

Complements

• bevy-platform-desktop - Windowed targets.
• godot-project-templates - Equivalent Godot skill.

Downstream / consumers

• None yet.

Master

• bevy-master - Bevy router.