bedrock-samples/behavior_pack/entities/minecart.json

{
  "format_version": "1.12.0",
  "minecraft:entity": {
    "description": {
      "identifier": "minecraft:minecart",
      "is_spawnable": false,
      "is_summonable": true,
      "is_experimental": false
    },

    "components": {
      "minecraft:is_stackable": {
      },
      "minecraft:type_family": {
        "family": [ "minecart", "inanimate" ]
      },
      "minecraft:collision_box": {
        "width": 0.98,
        "height": 0.7
      },
      "minecraft:rail_movement": {
      },
      "minecraft:rideable": {
        "seat_count": 1,
        "interact_text": "action.interact.ride.minecart",
        "pull_in_entities": true,

        "seats": {
          "position": [ 0.0, -0.2, 0.0 ]
        }
      },
      "minecraft:rail_sensor": {
        "eject_on_activate": true
      },
      "minecraft:physics": {
      },
      "minecraft:pushable": {
        "is_pushable": true,
        "is_pushable_by_piston": true
      },
      "minecraft:conditional_bandwidth_optimization": {
        "default_values": {
          "max_optimized_distance": 60.0,
          "max_dropped_ticks": 20,
          "use_motion_prediction_hints": true
        },
        "conditional_values": [
          {
            "max_optimized_distance": 0.0,
            "max_dropped_ticks": 0,
            "conditional_values": [
              { "test": "is_moving", "subject": "self", "operator": "==", "value": true}
            ]
          }
        ]
      }
    }
  }
}