| Name | Type | Description | Notes |
|---|---|---|---|
| fromUserId | String | Sender user ID. | |
| toChannelIds | List<String> | Target open channel IDs. Multiple channels are allowed; the official documentation recommends up to 10 IDs per request. | |
| messageType | String | Message type. Supports built-in types and custom types registered in the client SDK. Custom types must not start with `RC:` and must not exceed 32 characters. | |
| content | String | Message content payload serialized as a string. Built-in message types should use a JSON object string. Maximum size is 128 KB. | |
| shouldPersist | Integer | Whether to store the message in open channel cloud history. `0` means do not store and `1` means store. | [optional] |
| isEchoToSender | Integer | Whether to sync the sent message to the sender's client while online. `1` enables sync and `0` disables it. | [optional] |
| priority | Integer | Message priority. `0` standard, `1` allowlisted, `2` high priority, `3` low priority. | [optional] |