| Name | Type | Description | Notes |
|---|---|---|---|
| txid | number | Order ID; omit or `0` to return the latest order with chat for the user. | [optional] [default to undefined] |
| lastreceived | number | Timestamp of the last received message for backward incremental fetch; omit on first load. | [optional] [default to undefined] |
| firstreceived | number | Timestamp of first received message for paging backward; omit on first load. | [optional] [default to undefined] |