matrix-spec/api/client-server/definitions/event_batch.json

{
  "type": "object",
  "properties": {
    "events": {
      "type": "array",
      "description": "List of events",
      "items": {
        "type": "object",
        "allOf": [{"$ref": "event.json" }]
      }
    }
  }
}