{
  "$schema": "urn:prism:schema:v1:spec",
  "title": "Brand score (Pulse-backed bar)",
  "description": "Validates field-existence rules against the real schema in testdata/cohorts/tiny.pulse.",
  "data": {
    "name": "tiny",
    "source": "testdata/cohorts/tiny.pulse"
  },
  "mark": "bar",
  "encoding": {
    "x": {"field": "brand_id", "type": "nominal"},
    "y": {"field": "score", "type": "quantitative", "aggregate": "mean"}
  }
}