{
  "format_version": "1.21.60",
  "minecraft:feature_rules": {
    "description": {
      "identifier": "minecraft:swamp_after_surface_single_firefly_bush_cluster",
      "places_feature": "minecraft:firefly_bush_cluster_feature"
    },
    "conditions": {
      "placement_pass": "after_surface_pass",
      "minecraft:biome_filter": [
        { "test": "has_biome_tag", "value": "swamp" }
      ]
    },
    "distribution": {
      "iterations": 1,
      "scatter_chance": {
        "numerator": 1,
        "denominator": 16
      },
      "x": 0,
      "y": "query.heightmap(variable.worldx, variable.worldz)",
      "z": 0
    }
  }
}
