Bevy app resources (docs-first stub)
Not a full port. App-wide data is a Resource on the World. There is no autoload and no singleton node.
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
Appcontains aWorldand the outer loop. It initializes resources (one copy), adds systems to aSchedule, and imports otherAppchanges through plugins. - Resources.
Resource,Res,ResMut, andinsert_resource(Resources page).Timearrives fromadd_plugins(DefaultPlugins). - Plugins. The Resources page implements
Pluginand inserts the resource insidebuild.DefaultPluginsis the plugin set that addsTime. Do not add further plugin names in this stub. - 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::messagenamesFixedUpdateonly as the schedule after whichsignal_message_update_systemruns. Fixed-timestep clock types stay in bevy-character-movement. - States. App-wide modes are
bevy::state, not a global node. See bevy-state-machines.
Godot idea to Bevy idiom
| Idea | Bevy idiom (idea only) |
|---|---|
| Autoload singleton | A Resource inserted on the App |
| Global script that ticks | A system on Update (or a chained pair) |
| Boot setup | A Startup system or insert_resource in a Plugin |
| Cross-scene bus | A message or event. See bevy-events-messaging. Not a persistent node |
Gaps
- Plugin dependency order and groups were not opened.
- Sub-apps were named on the state module (
SubApp) and not opened here. - Save-game resources and settings files were not opened (
bevy_settingsis a feature name on the crate page only).
Expert Knowledge Delta
Library target in prose: Bevy 0.20.0. Lattice URLs stay unversioned.
Opened canon only: Component, Resource, Query, Commands, Startup, Update, Fixed / FixedMain (bevy::time), .chain(), Plugin, DefaultPlugins, MinimalPlugins. Messages and observers are an ownership slot. This file does not invent their struct 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 Godot node script |
| 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 this skill did not open | A Gaps row | A fabricated crate (solver, navmesh module, net, XR) |
Load references/a-gate-notes.md for the same table plus the gap rule.
NEVER
-
Do not put
/0.20.0/in lattice URLs. WHY: permalinks stay onlatest. The 0.20.0 pin belongs in prose once. -
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: those rows are gaps, blocked, or revisit.
-
No autoload, singleton node, or signal bus. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar.
-
No Godot types. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar.
-
No invented plugin lists beyond
DefaultPluginsand thePlugintrait the Resources page uses. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar. -
No third-party crates. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar.
-
No Creation Station content. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar.
-
No umbrella skill over Godot and Bevy. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar.
-
Do not mark this row
ported. It isdocs_mapped. WHY: a Godot port, an unopened API, or a public lie fails the docs-first bar.
Reference
docs.rs links use the unversioned latest permalink. The library pin on bevy-master stays 0.20.0.
Official Documentation
- Migration guides - Unversioned hop index.
- bevy crate - Unversioned API index.
default_appincludesbevy_stateandbevy_log. - Apps -
App,World, resources,Schedule, plugins. - Resources -
Resource,insert_resource,Plugin::build,DefaultPlugins,Time. - Quick Start: ECS -
Startup,Update,add_systems,.chain(). - Examples - Example tree on the
latestbranch.
Related Skills
Prerequisites
- bevy-master - No autoload layer on top of the schedule.
- bevy-project-foundations - Crate and
App::new().
Complements
- bevy-data-resources - When data is a component instead of a resource.
- bevy-state-machines - App-wide
Statesinstead of a global mode flag on a node. - godot-autoload-architecture - Godot counterpart. Source idea only. Do not import Godot types.
Downstream / consumers
- None yet. Save, audio, and scene skills are not ported.
Master
- bevy-master - Bevy router.


