OpenMetrics

message Metric {
  string       name  
  string       help  
  Type         type  # float64 / int64 / bool / enum
  Kind         kind  # cumulative / gauge / untyped
  Structure    struct  # scalar / historgram / summary
  
  repeated     Child    children

  # Q: list label keys here
}

message Child {
  repeated LabelPair labels
  int64     timestamp_ms  # Q: here?

  # One off:
  Scalar         scalar
  Summary        summary
  Histogram      gauge_histogram    

  # Q: also multiply out each type?
}

message Scalar {
  Value value
}

message Summary {
  uint64   sample_count
  Value    sample_sum   
  repeated Quantile quantile
}

message Quantile {
  double quantile
  Value value
}

message Histogram {
  uint64   sample_count
  Value    sample_sum
  repeated Bucket bucket
}

message Bucket {
  uint64 count = 1
  Value  upper_bound = 2
}

message Value {
  double double
  int64  int64
  bool   bool
  string enum
}