Bevy Ecs
gamedev-skills/awesome-gamedev-agent-skills
Structure a Bevy app around its Entity Component System: build the App with plugins, define Component/Resource types, write systems with Query/Res/Commands, filter and order systems, and use the…
Reference for writing Bevy ECS queries — Query<D, F, Single, filters, component access, iteration patterns, lenses, disjointed access, and testing.
MITAuto-check passed
Install Bevy Queries
$ npx skills add nolantait/bevy-starter --skill bevy-queries -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install nolantait/bevy-starter bevy-queries --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/nolantait/bevy-starter.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/bevy-queries .claude/skills/bevy-queries && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "bevy-queries" agent skill from https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queries into .claude/skills/bevy-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bevy-queries", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queriesType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add nolantait/bevy-starter --skill bevy-queries -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install nolantait/bevy-starter bevy-queries --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nolantait/bevy-starter.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/bevy-queries .agents/skills/bevy-queries && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "bevy-queries" agent skill from https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queries into .agents/skills/bevy-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bevy-queries", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add nolantait/bevy-starter --skill bevy-queries -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install nolantait/bevy-starter bevy-queries --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nolantait/bevy-starter.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/bevy-queries .cursor/skills/bevy-queries && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "bevy-queries" agent skill from https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queries into .cursor/skills/bevy-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bevy-queries", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/nolantait/bevy-starter.git --path .agents/skills/bevy-queries--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add nolantait/bevy-starter --skill bevy-queries -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install nolantait/bevy-starter bevy-queries --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nolantait/bevy-starter.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/bevy-queries .gemini/skills/bevy-queries && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "bevy-queries" agent skill from https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queries into .gemini/skills/bevy-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bevy-queries", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install nolantait/bevy-starter bevy-queriesInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add nolantait/bevy-starter --skill bevy-queries -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/nolantait/bevy-starter.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/bevy-queries .github/skills/bevy-queries && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "bevy-queries" agent skill from https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queries into .github/skills/bevy-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bevy-queries", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add nolantait/bevy-starter --skill bevy-queries -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install nolantait/bevy-starter bevy-queries --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/nolantait/bevy-starter.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/bevy-queries .opencode/skills/bevy-queries && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "bevy-queries" agent skill from https://github.com/nolantait/bevy-starter/tree/master/.agents/skills/bevy-queries into .opencode/skills/bevy-queries/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bevy-queries", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
bevy-queries- GitHub stars
- 132
- Token cost
- ~1.7k tokens
- SKILL.md length
- 451 words
- Files
- 1
- Skills in repo
- 24
- Repo updated
- First seen
- Licence
- MIT
At a glance
Reference for writing Bevy ECS queries — Query<D, F, Single, filters, component access, iteration patterns, lenses, disjointed access, and testing.
- SKILL.md covers Basics, Component mutability, Tuple = AND logic and Alternative query parameters, plus 7 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Bevy Queries is an agent skill from nolantait/bevy-starter. Reference for writing Bevy ECS queries — Query<D, F, Single, filters, component access, iteration patterns, lenses, disjointed access, and testing.
Its SKILL.md is about 1.7k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: A minimalist starter for bevy and rust. The licence is MIT.
Example prompts
- “/bevy-queries”
What it can do on your machine
Read from SKILL.md and the folder at commit dd6f56b. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are rust).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Bevy Queries loads about 1.7k tokens when it runs. Until then it costs about 40 tokens; SKILL.md has 451 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from nolantait/bevy-starter at commit dd6f56b, republished under its MIT licence (© nolantait). 451 words, ~1,661 tokens.
Download SKILL.mdSave it as
.claude/skills/bevy-queries/SKILL.md (or your agent's skills folder).- name
- bevy-queries
- description
- Reference for writing Bevy ECS queries — Query<D, F>, Single, filters, component access, iteration patterns, lenses, disjointed access, and testing.
- metadata.crate
- bevy_ecs
- metadata.bevy
- 0.19
Basics
Query<D, F> is a system parameter. D = query data (what to fetch), F = query filter (conditions). Data is only fetched when iterated.
fn system(query: Query<&Transform>) {
for transform in &query { }
}Component mutability
| Syntax | Meaning |
|---|---|
Query<&T> | Readonly borrow — parallel-friendly |
Query<&mut T> | Mutable borrow — blocks parallel access to same component |
Query<Option<&T>> | Optional component — entity may or may not have it |
Tuple = AND logic
Each generic parameter in Query<D, F> can be a tuple. All types must match.
Query<(&Ball, &Player)> // entities with both Ball AND Player
Query<&Transform, (With<Player>, With<Living>)> // Transform on entities with Player AND LivingAlternative query parameters
| Parameter | Behavior |
|---|---|
Single<D, F> | Exactly one match, or system skipped |
Option<Single<D, F>> | Zero or one match; yields None if there are none or more than one |
Populated<D, F> | One or more matches, skips if none |
fn move(mut t: Single<&mut Transform, With<Player>>) {
t.translation.x += 1.;
}
fn destructure(s: Single<(&mut Pos, &Vel), With<Player>>) {
let (mut pos, vel) = s.into_inner();
}QueryData (D parameter)
| Type | Description |
|---|---|
&T / &mut T | Read or write component |
Option<T> | Component or None |
AnyOf<T> | Fetch entities matching any of the tuple types |
Ref<T> | Readonly with change detection methods |
Has<T> | Returns bool if entity has component |
Entity | The entity ID |
SpawnDetails | When paired with the Spawned filter, gives access to when and where an entity was spawned |
AnyOf
Query<AnyOf<(&Player, &Rocket, &mut Astroid)>>
// Expands to: Query<(Option<&P>, Option<&R>, Option<&mut A>), Or<(With<P>, With<R>, With<A>)>>Ref (change detection)
fn check(q: Query<Ref<Player>>) {
for p in &q {
if p.is_added() { }
if p.is_changed() { }
// p.last_changed()
}
}Entity ID
fn with_id(q: Query<(Entity, &Transform)>) {
for (entity, transform) in &q { }
}
fn lookup(players: Query<Entity, With<Player>>, transforms: Query<&Transform>) {
for e in &players {
let t = transforms.get(e).unwrap();
}
}QueryFilter (F parameter)
| Filter | Description |
|---|---|
With<T> | Only entities with component T |
Without<T> | Only entities without component T |
Or<F> | Checks if any filters in the tuple F apply |
Changed<T> | Components of type T that changed since the system last ran |
Added<T> | Components of type T that were added since the system last ran |
Spawned | Only entities that were spawned since the system last ran |
Query<&Transform, (With<Player>, Without<Dead>)>
Query<Player, Added<Player>> // equivalent to Ref<Player> + is_added check
Query<(&Player, SpawnDetails), Spawned> // newly spawned entitiesShow full SKILL.md (217 more words)Show less
Retrieval methods
| Method | Description |
|---|---|
iter / iter_mut | Iterator over all matches |
iter_many / iter_many_mut | Iterate over only the items matching a list of entities |
iter_combinations / iter_combinations_mut | All K-combinations of matches |
contiguous_iter / contiguous_iter_mut | Receives whole table slices at once, enabling SIMD optimizations |
par_iter / par_iter_mut | Parallel iterator |
get / get_mut | Fetch a single entity's components by Entity |
get_many / get_many_mut | Fetch items for each entity in a fixed-size array |
single / single_mut | The only query item as a Result, Err unless there is exactly one |
is_empty | Check if query has matches |
contains | Check if query contains a specific entity |
Every method that returns query items has a *_mut variant; the *_mut methods
require a mutable Query parameter.
// Iteration
for mut t in &mut query { }
query.iter_mut().for_each(|mut t| { });
// Specific entity
if let Ok(t) = query.get(entity) { }
// Combinations
for [a, b] in query.iter_combinations() { }
// Many entities
let mut iter = query.iter_many_mut(&entities);
while let Some(mut h) = iter.fetch_next() { }Query lenses
Share common query logic without duplicating system parameters.
fn print_health(lens: &mut QueryLens<&Health>) {
for h in &mut lens.query() {
if h.0 > 50.0 { info!("healthy"); }
}
}
fn player_system(mut q: Query<(&Health, &Player)>) {
print_health(&mut q.transmute_lens::<&Health>());
}
fn enemy_system(mut q: Query<(&Health, &Enemy, &Transform)>) {
print_health(&mut q.transmute_lens::<&Health>());
}transmute_lens— narrow query datatransmute_lens_filtered— include filterjoin/join_filtered— combine queries
Disjointed queries & ParamSet
Two queries with mutable access to overlapping component sets: use Without to disambiguate, or use ParamSet (which serializes access at runtime).
// Will panic at runtime — ambiguous borrows
fn bad(p: Query<&mut Player, With<Rocket>>, e: Query<&mut Player, With<Invincibility>>) { }
// Safe: serialized access
fn ok(p: ParamSet<(Query<&mut Player, With<Rocket>>, Query<&mut Player, With<Invincibility>>)>) { }
// Or with disjoint archetypes (Bevy 0.12+):
fn disjoint(t: Query<EntityMut, With<Transform>>, e: Query<EntityMut, Without<Transform>>) { }Performance notes
Tablestorage iterates faster thanSparseSet- Two systems with conflicting mutable access to the same component type cannot run in parallel
for_eachis generally faster thaniteron worlds with high archetype fragmentation- Prefer
iteroverfor_eachunless profiling shows a need - Accessing
entity.get_components_mut::<(&mut A, &mut B)>()has quadratic cost over number of components
Testing
Use app.world_mut().run_system_once(fn) or access app.world_mut().query::<T>():
#[cfg(test)]
mod tests {
use super::*;
fn setup_app() -> App {
let mut app = App::new();
app.add_plugins((MinimalPlugins, plugin));
app
}
fn check_ship(query: Query<&Ship>) {
assert_eq!(query.iter().count(), 1);
}
#[test]
fn test_spawn() {
let mut app = setup_app();
app.update();
app.world_mut().run_system_once(check_ship).unwrap();
}
}© nolantait, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .agents/skills/bevy-queries of nolantait/bevy-starter.
Open the folder on GitHubat commit dd6f56b
Compare with similar skills
Bevy Queries next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Bevy Queries this skillnolantait/bevy-starter | 132 | — | ~1.7k | Automated safety check: Pass | MIT | |
| Bevy Ecsgamedev-skills/awesome-gamedev-agent-skills | 1.4k | — | ~2.5k | Automated safety check: Pass | Apache-2.0 | |
| ClickHouse Query Performance Validationcomet-ml/opik | 22k | — | ~2.1k | Automated safety check: Pass | Apache-2.0 | |
| Analyzing Experiment Query PerformancePostHog/posthog | 40k | — | ~3.7k | Automated safety check: Pass | Custom licence | |
| Bevy Ecs Expertaiskillstore/marketplace | 433 | 3 repos | ~924 | Automated safety check: Pass | None | |
| Frontend Query Mutationlangflow-ai/langflow | 155k | — | ~979 | Automated safety check: Pass | MIT |
Similar skills
ClickHouse Query Performance Validation
comet-ml/opik
Measures what a ClickHouse query change actually costs, turning a suspicion that a query is slow into numbers a reviewer can act on before it merges.
- Official
Analyzing Experiment Query Performance
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Pull and interpret production experiment query-performance data from the staff-only /api/debugchqueries endpoints backing the /experiments/staff scene: slowest experiment queries, precompute…
Bevy Ecs Expert
aiskillstore/marketplace
Master Bevy's Entity Component System (ECS) in Rust, covering Systems, Queries, Resources, and parallel scheduling.
Frontend Query Mutation
langflow-ai/langflow
Guide for implementing Langflow frontend query and mutation patterns with Axios and TanStack React Query v5.
- Official
Studio Queries
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React Query conventions for data fetching in Supabase Studio.
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Questions about Bevy Queries
What does Bevy Queries do?
Reference for writing Bevy ECS queries — Query<D, F, Single, filters, component access, iteration patterns, lenses, disjointed access, and testing. Bevy Queries is an agent skill from nolantait/bevy-starter. Reference for writing Bevy ECS queries — Query<D, F, Single, filters, component access, iteration patterns, lenses, disjointed access, and testing.
How do I install Bevy Queries in Claude Code?
Run `npx skills add nolantait/bevy-starter --skill bevy-queries -a claude-code`. Or copy the skill folder (.agents/skills/bevy-queries in nolantait/bevy-starter) into .claude/skills/bevy-queries in your project. Claude Code loads it when a task matches its description.
How do I install Bevy Queries in Codex?
Run `npx skills add nolantait/bevy-starter --skill bevy-queries -a codex`. Or copy the skill folder (.agents/skills/bevy-queries in nolantait/bevy-starter) into .agents/skills/bevy-queries in your project. Codex loads it when a task matches its description.
Can I use Bevy Queries in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add nolantait/bevy-starter --skill bevy-queries -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/bevy-queries, .gemini/skills/bevy-queries, .github/skills/bevy-queries and .opencode/skills/bevy-queries in your project.
What does Bevy Queries need to run?
SKILL.md names no scripts, command-line tools or credentials: Bevy Queries is instructions for the agent only.
Does Bevy Queries access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Bevy Queries safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Bevy Queries use?
Bevy Queries is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Bevy Queries use?
About 1.7k tokens (SKILL.md is roughly 6.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Bevy Queries?
Skills that share tags, products or a category with Bevy Queries: Bevy Ecs (gamedev-skills/awesome-gamedev-agent-skills, 1.4k stars), ClickHouse Query Performance Validation (comet-ml/opik, 22k stars), Analyzing Experiment Query Performance (PostHog/posthog, 40k stars) and Bevy Ecs Expert (aiskillstore/marketplace, 433 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Bevy Queries?
nolantait (a GitHub user) maintains it in nolantait/bevy-starter, which has 132 GitHub stars. The repository holds 24 skills in this directory. The repository was last updated on October 8, 2026.
Source: nolantait/bevy-starter on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.