{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:orbiplex:schema:middleware-channel-heartbeat:v1",
  "title": "Middleware Channel Heartbeat v1",
  "description": "Bounded application-level liveness signal for one channel session.",
  "type": "object",
  "additionalProperties": false,
  "required": ["schema", "schema/v", "sent/at"],
  "properties": {
    "schema": {"const": "middleware-channel-heartbeat.v1"},
    "schema/v": {"const": 1},
    "sent/at": {"type": "string", "format": "date-time", "maxLength": 64}
  },
  "x-dia-basis": [
    "orbidocs:doc/project/40-proposals/080-multiplexed-middleware-channel-executor.md"
  ]
}