| Name | Type | Description | Notes |
|---|---|---|---|
| channel_type | int | Channel type. Supports `1` direct, `3` group, `4` open channel, and `6` system (`HistoryCleanInput`). | |
| from_user_id | string | User whose server-side history is operated on. For open channels, this is the operator ID. | |
| channel_id | string | Target channel ID (`targetId` / conversation target). | |
| sent_at | string | Optional cutoff (`msgTimestamp`). Serialized as string in `HistoryCleanInput`. | [optional] |