Bevy Migration 0 18 To 0 19

Bevy 0.18 → 0.19 — Migration cheat sheet

Released 2026-06-18. Apply top-down — earlier items break later builds if skipped.

When to use this skill

• Compiler errors after a bevy = "0.18" → bevy = "0.19" bump.
• LLM emits 0.18-era text/font/scene API names from training data.
• A #[derive(Resource)] type suddenly behaves like a component.
• A third-party crate (bevy_capture, etc.) hasn't shipped 0.19 yet.

The renames you'll hit first

Text layout: drop the new_with_ prefix

// 0.19
TextLayout::justify(Justify::Left)   // was new_with_justify
TextLayout::linebreak(/* … */)       // was new_with_linebreak
TextLayout::no_wrap()                // was new_with_no_wrap

TextFont fields changed type: FontSource + FontSize

// 0.19 — font is FontSource (handle OR family), font_size is FontSize
TextFont {
    font: asset_server.load("fonts/FiraSans-Bold.ttf").into(), // Handle → FontSource via .into()
    font_size: FontSize::Px(24.0),                             // f32 → FontSize::Px / ::Vh / ::Rem
    ..default()
}
// Select by family (needs the `bevy/system_font_discovery` feature for installed fonts):
TextFont { font: FontSource::family("Fira Sans"), ..default() }

0.19 swapped the cosmic-text layout backend for Parley, which does font fallback automatically via fontique. The old "insert a DefaultFontHandle so ..default() entities inherit a font" trick is obsolete — see [references/text-and-fonts.md](references/text-and-fonts.md).

Scene serialization crate was renamed (silent wrong-crate trap)

bevy_scene is reused for the new BSN system. Classic DynamicScene round-trip serialization moved to bevy_world_serialization:

// 0.18  → 0.19
// bevy_scene::DynamicScene          → bevy_world_serialization::DynamicWorld
// bevy::scene::SceneRoot            → bevy::world_serialization::WorldAssetRoot
// DynamicSceneBuilder               → DynamicWorldBuilder
// SceneSpawner                      → WorldInstanceSpawner

glTF scene spawning still uses the old (now world_serialization) system. Full table: [references/scene-serialization.md](references/scene-serialization.md).

Resources are now Components (mostly a mental-model change)

Res, ResMut, #[derive(Resource)], and insert_resource all still work. The narrow breakages:

// ILLEGAL in 0.19 — a type can no longer be both:
#[derive(Component, Resource)] struct Health(u32);

Plus: a resource type now also matches Query, and inserting it as a component can despawn other copies. Non-send resource methods were renamed (deprecated, not removed):

world.init_non_send::();    // was init_non_send_resource
world.get_non_send::();     // was get_non_send_resource

Details + the query/despawn footgun: [references/resources-as-components.md](references/resources-as-components.md).

Cargo feature implications tightened

# 0.19: audio is NO LONGER implied by 2d / 3d / ui — add it explicitly:
bevy = { version = "0.19", features = ["3d", "bevy_audio", "vorbis"] }
# ui is NO LONGER implied by 2d / 3d either — add "ui" if you build UI.

Feathers UI stabilized

experimental_ dropped. FeathersPlugin → FeathersCorePlugin, and widget components lost their Core prefix (CoreScrollbarThumb → ScrollbarThumb, CoreSliderDragState → SliderDragState, etc.). Only relevant if you use Feathers.

Third-party crates lag the release

bevy_capture (the crate behind bevy-capture) tracks Bevy and may not have a 0.19 release yet — verify a 0.19-compatible version exists before bumping. When it does, EasyScreenRecordPlugin gained a required output_dir: Option field (only breaks manual struct construction; ..default() is fine).

Gotchas

• #[reflect(Resource)] reflection access now also needs ReflectComponent in some paths.
• TextFont::default().font is a FontSource, not a Handle — code that read it as a handle won't compile.
• System font discovery needs the bevy/system_font_discovery feature; on Linux also libfontconfig1-dev.
• The fallback setters (set_serif_family, etc.) now return Result — and you mostly shouldn't need them under Parley.

See also

• bevy-migration-0-17-to-0-18 — the previous release's rename catalogue.
• bevy-ui — TextFont/FontSize/FontSource in everyday UI code.
• bevy-cargo-features — feature-implication table and renames.
• bevy-ecs-components — the Component model the new Resource subtrait plugs into.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: chrisgliddon
• Source: chrisgliddon/bevy-skills
• License: MIT

Install and usage instructions live in the source repository linked above.