# Bevy App Resources

Bevy ECS skill for app-wide resources and schedules.

- Repository: https://github.com/thedivergentai/Game-Dev-Agentic-Skills (917 stars)
- Category: Engineering
- License: LGPL-3.0
- Last updated: 2026-10-16
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add thedivergentai/Game-Dev-Agentic-Skills --skill bevy-app-resources -g -a claude-code -y`
Codex: `npx skills add thedivergentai/Game-Dev-Agentic-Skills --skill bevy-app-resources -g -a codex -y`
Cursor: `npx skills add thedivergentai/Game-Dev-Agentic-Skills --skill bevy-app-resources -g -a cursor -y`
Gemini CLI: `npx skills add thedivergentai/Game-Dev-Agentic-Skills --skill bevy-app-resources -g -a gemini-cli -y`

## Description

Bevy ECS skill for app-wide resources and schedules. Keywords: Bevy, Resource, App, Schedule, Plugin.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Bevy app resources

## When to use

Load this when data or logic must exist for the whole app: one clock, one ruleset, startup spawn, or an ordered pair of systems. Pair with bevy-data-resources for the component-versus-resource split.

## ECS shape

- **App.** The Apps page: an `App` contains a `World` and the outer loop. It initializes resources (one copy), adds systems to a `Schedule`, and imports other `App` changes through plugins.
- **Resources.** `Resource`, `Res`, `ResMut`, and `insert_resource` (Resources page). `Time` arrives from `add_plugins(DefaultPlugins)`.
- **Plugins.** The Resources page implements `Plugin` and inserts the resource inside `build`. `DefaultPlugins` is the plugin set that adds `Time`. Name only the plugins this page documents.
- **Schedules.** `add_systems(Startup, ...)` runs once before other systems. `add_systems(Update, ...)` is the repeating schedule in the ECS page. `.chain()` orders systems that must see each other's writes. `bevy::ecs::message` names `FixedUpdate` only as the schedule after which `signal_message_update_system` runs. Fixed-timestep clock types stay in bevy-character-movement.
- **States.** App-wide modes are `bevy::state`, not a global node. See bevy-state-machines.

## App choices

| Need | Bevy idiom |
| --- | --- |
| One copy for the whole app | A `Resource` inserted on the `App` |
| Logic that ticks every frame | A system on `Update` (or a chained pair) |
| Boot setup | A `Startup` system or `insert_resource` in a `Plugin` |
| One-shot notice | A message or event. See bevy-events-messaging. |

## Scope

- Insert app-wide data with `insert_resource` inside `Plugin::build`, or from a `Startup` system.
- Order two systems that both mutably use the same resource with `.chain()`.
- Save files are a `Resource` you serialize yourself. The running copy stays in the `World`.

## Examples

```toml
[package]
name = "app_resources"
version = "0.1.0"
edition = "2021"

[dependencies]
bevy = "0.20"
```

The rest: https://github.com/thedivergentai/Game-Dev-Agentic-Skills/blob/HEAD/skills/bevy-app-resources/SKILL.md