Bevy audio systems

When to use

Load this when a clip should start, loop, pause, or change volume. bevy::audio in Bevy 0.20 and the audio_control example are the sources.

ECS shape

• Play: spawn AudioPlayer::new(asset_server.load(...)). AudioPlayer<Source> holds Handle<Source> where Source: Asset + Decodable. If the asset is not ready, playback starts when it is. AudioPlayer requires PlaybackSettings.
• Settings: PlaybackSettings configures the start. PlaybackSettings::LOOP and .with_spatial(true) appear in the spatial examples. Changes to PlaybackSettings do not affect audio that is already playing. PlaybackMode is Once, Loop, Despawn, or Remove.
• Control: when playback begins, Bevy inserts AudioSink. The control example queries AudioSink and calls pause, toggle_mute, set_volume, set_speed, and position. SpatialAudioSink is the spatial counterpart named on the playback page.
• Replay: after a non-looping sound finishes and the sink is drained, that AudioPlayer cannot be reused. Remove the audio components and add them again.
• Schedule: spawn on Startup or from a system that has Res<AssetServer> and Commands. Control systems in the example run where they read ButtonInput<KeyCode> and Res<Time>.

Playback pieces

Need	Bevy idiom
Start a file	AudioPlayer::new plus AssetServer::load
Loop	PlaybackSettings::LOOP
Pause, mute, or volume while playing	AudioSink methods on the same entity
One-shot that should leave the world	PlaybackMode::Despawn or Remove
Positional emitter	PlaybackSettings with with_spatial(true) and SpatialAudioSink

Examples

[dependencies]
bevy = "0.20"

AudioPlayer starts when the handle is ready. PlaybackSettings applies only at that start. AudioSink is inserted once playback begins and is the live control.

use bevy::audio::{AudioSinkPlayback, Volume};

fn spawn_music(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn((
        AudioPlayer::new(asset_server.load("audio/music.ogg")),
        PlaybackSettings::LOOP.with_volume(Volume::Linear(0.6)),
    ));
}

fn spawn_oneshot(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn((
        AudioPlayer::new(asset_server.load("audio/ui.ogg")),
        PlaybackSettings::DESPAWN,
    ));
}

fn duck_music(mut sinks: Query<&mut AudioSink>) {
    for mut sink in &mut sinks {
        sink.set_volume(Volume::Linear(0.25));
        sink.pause();
    }
}

A positional emitter sets with_spatial(true) and a Transform. Live control of that emitter uses SpatialAudioSink.

use bevy::audio::{AudioSinkPlayback, Volume};

fn spawn_footstep(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn((
        AudioPlayer::new(asset_server.load("audio/step.ogg")),
        PlaybackSettings::ONCE.with_spatial(true),
        Transform::from_xyz(3.0, 0.0, 1.0),
    ));
}

fn quiet_nearby(mut sinks: Query<&mut SpatialAudioSink>) {
    for mut sink in &mut sinks {
        sink.set_volume(Volume::Linear(0.5));
    }
}

A finished non-looping player cannot be reused. Drop the player and the sink, then insert them again with the same handle.

use bevy::audio::AudioSinkPlayback;

fn replay_when_empty(mut commands: Commands, playing: Query<(Entity, &AudioPlayer, &AudioSink)>) {
    for (entity, player, sink) in &playing {
        if !sink.empty() {
            continue;
        }
        let handle = player.0.clone();
        commands.entity(entity).remove::<AudioPlayer>().remove::<AudioSink>();
        commands.entity(entity).insert((
            AudioPlayer::new(handle),
            PlaybackSettings::ONCE,
        ));
    }
}

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 plain struct stored outside the world
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.

• Do not change PlaybackSettings to retune audio that is already playing. WHY: those settings apply only when playback starts; live control is AudioSink.

• No volume curves or mixer nodes this file did not open. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

• No third-party audio crates. WHY: Bevy code stays idiomatic ECS and uses only documented Bevy APIs.

Reference

The library pin on bevy-master stays 0.20.0. Permalinks stay unversioned.

Official Documentation

• Assets - Official asset catalog.
• Examples - Example tree on the latest branch.
• Audio examples - Playback, spatial, and control samples.
• ECS - Component, systems, Query, Startup, Update, and .chain().

Related Skills

Prerequisites

• bevy-master - Who owns which piece of state.
• bevy-asset-scenes - AssetServer and Handle.

Complements

• bevy-input-handling - Keys the control example uses.

Downstream / consumers

• None yet. Genre skills that play stingers should route here when they exist.

Master

• bevy-master - Bevy router.