bevy-query

Connect to the Bevy remote inspector at http://127.0.0.1:15702 via JSON-RPC.

Methods (Bevy 0.18)

Method	Purpose
rpc.discover	List available methods
world.query	Query entities by components, with optional filter
world.get	Get components from a specific entity by ID
world.list	List all registered component types
world.spawn	Spawn a new entity
world.despawn	Despawn an entity
world.insert	Insert components on an entity
world.remove	Remove components from an entity
world.reparent	Change entity parent

Type path conventions

Component types use their full Rust module path (where defined, not re-exported):

• Crate types: hex_terrain::terrain::entities::HexSunDisc
• Bevy Transform: bevy_transform::components::transform::Transform
• Marker components: hex_terrain::drone::entities::Player

Query examples

Count entities with a component

{
  "jsonrpc": "2.0", "method": "world.query", "id": 0,
  "params": {
    "data": {
      "components": ["hex_terrain::terrain::entities::HexSunDisc"]
    }
  }
}

Response: .result is an array — use jq '.result | length' to count.

Query component data with a filter

Fetch Transform on entities that have a Player marker:

{
  "jsonrpc": "2.0", "method": "world.query", "id": 0,
  "params": {
    "data": {
      "components": ["bevy_transform::components::transform::Transform"]
    },
    "filter": {
      "with": ["hex_terrain::drone::entities::Player"]
    }
  }
}

Response structure:

{
  "result": [
    {
      "entity": "4294967298v1",
      "components": {
        "bevy_transform::components::transform::Transform": {
          "translation": { "x": 0.0, "y": 12.0, "z": 0.0 },
          "rotation": [0.0, 0.0, 0.0, 1.0],
          "scale": { "x": 1.0, "y": 1.0, "z": 1.0 }
        }
      }
    }
  ]
}

Extract a field: jq '.result[0].components["...Transform"].translation.y'

Query params reference

{
  "data": {
    "components": ["..."],  // components to return data for (required)
    "option": ["..."],      // optional components (may be absent)
    "has": ["..."]          // boolean presence check (no data returned)
  },
  "filter": {
    "with": ["..."],        // required components (not returned in data)
    "without": ["..."]      // excluded components
  }
}

curl one-liner

curl -sf -X POST http://127.0.0.1:15702 \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"world.query","id":0,"params":{"data":{"components":["COMPONENT_PATH"]}}}' \
  | jq '.result | length'