let connection_kind_type = [|
  'LibraryDependency,
  'DeployedBy,
  'CoDeveloped,
  'DataSource,
  'EventConsumer,
  'EventProducer,
  'Monitoring,
  'Unknown,
|] in

let connection_type = {
  project | String,
  kind    | connection_kind_type,
  note    | String | default = "",
  url     | String | default = "",
  # Ontology node ID in the target project's DAG (e.g. "dag-formalized").
  # Enables cross-project node resolution for impact analysis.
  node    | String | default = "",
  # Transport or protocol used to reach the target (e.g. "http", "nats", "direct", "git").
  # Used by federation.rs to select the resolution strategy.
  via     | String | default = "",
} in

let connections_type = {
  upstream   | Array connection_type | default = [],
  downstream | Array connection_type | default = [],
  peers      | Array connection_type | default = [],
} in

{
  Connection  = connection_type,
  Connections = connections_type,
}