bevy-project-templates

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.