bevy

name	bevy
description	Build Rust games with Bevy: ECS mental model, plugins, schedules, states, assets, 2D sprites, fast iteration (cargo check, dynamic_linking, opt-level), backgrounded cargo run plus game_playtest. Use when the owner mentions Bevy or Cargo.toml depends on bevy.
version	1.0.0
author	Remedy
tags	["game","bevy","rust","ecs","cargo"]
requires	[]
tools	["game_project_info","bash_exec","file_read","file_write","file_edit","repo_search","list_dir","game_playtest","computer_screenshot","vision_decode"]
triggers	["\\bbevy\\b"]

Bevy (Rust ECS engine)

Bevy compiles slowly and changes API every minor version. Two habits keep you honest: check the version in Cargo.toml before writing a line, and use cargo check as the oracle between edits instead of full builds.

Fingerprint

1. game_project_info(path); file_read Cargo.toml → bevy = "0.x" and its features. Cargo.lock has the exact patch.
2. src/main.rs (App builder), src/** plugins, assets/ (default asset root, relative to the crate).
3. .cargo/config.toml → linker / -Zshare-generics tweaks already set.
4. Rust toolchain: cargo --version, rustc --version. No cargo → say so; you can still write code but cannot verify it.

Version discipline. Names moved between releases (SpriteBundle → Sprite component in 0.15; Camera2dBundle → Camera2d; add_system → add_systems(Schedule, …) in 0.11; Color::rgb → Color::srgb in 0.14). When unsure, repo_search the crate source under ~/.cargo/registry/src/*/bevy_*-<ver>/ or read docs.rs/bevy/<ver>. Do not write from memory for a version you have not checked.

ECS in one breath

Entities are ids; components are plain structs (#[derive(Component)]); systems are functions whose parameters are queries and resources; resources are singletons (#[derive(Resource)]); events are queued messages (#[derive(Event)], EventWriter/EventReader). Systems run inside schedules: Startup once, Update every frame, FixedUpdate at a fixed rate (Time<Fixed>). Patterns, ordering, commands, change detection: references/ecs-patterns.md.

App skeleton

use bevy::prelude::*;

fn main() {
    App::new()
        .(DefaultPlugins)
        .(Startup, setup)
        .(Update, (movement, bounce).())
        .();
}