{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://transitapp.com/schemas/departure",
  "title": "Transit Departure",
  "description": "A scheduled or real-time transit departure from a stop",
  "type": "object",
  "required": ["route_id", "route_name", "headsign", "scheduled_time"],
  "properties": {
    "route_id": {
      "type": "string",
      "description": "Unique route identifier"
    },
    "route_name": {
      "type": "string",
      "description": "Human-readable route name or number"
    },
    "headsign": {
      "type": "string",
      "description": "Destination display text shown on the vehicle"
    },
    "scheduled_time": {
      "type": "string",
      "format": "date-time",
      "description": "Scheduled departure time in ISO 8601 format"
    },
    "real_time": {
      "type": ["string", "null"],
      "format": "date-time",
      "description": "Real-time predicted departure time, null if unavailable"
    },
    "wheelchair_accessible": {
      "type": "boolean",
      "description": "Whether the departing vehicle is wheelchair accessible"
    },
    "vehicle_id": {
      "type": ["string", "null"],
      "description": "Vehicle identifier for real-time tracking"
    }
  }
}